Scanner Review

A Brief History of Crosfield & Fujifilm Drum Scanners

2010-12-06T09:41:00.000-08:00

http://www.colourphil.co.uk/crosfield_scanner_intro.html

A Brief History of Crosfield & Fujifilm Drum Scanners

A little information on the world's finest drum scanners.The Magnascan 530 & 540 range were launched way back in 1981. They were virtually completely digital. They were modular with separate Analyse and Expose scanner units. The Analyse scanner used a xenon lamp which had a colour temperature of approximately 6200K (similar to "daylight"). The separate expose scanner used a laser in conjunction with a modulator and "contact screens" to expose the final positive or negative film. They were largely replaced by the 640 range launched a year later. These used a laser to directly expose the output film using "EDG" (Electronic Dot Generation) technology, later known as "MagnaDot". These eventually became the 635, 645 and later the 636, 646, etc. ("6X6").

In the early 90's various attempts were made to link Crosfield scanners to DTP systems. The best of these was the Magnalink 600, which linked the Analyse scanner only to a Mac computer. Earlier versions of Magnalink had used a Sun Sparc computer, and were often combined with "MagnaRip" to output film from Postscript pages.

These scanners were developed into the "Celsis" (Crosfield Electronics Ltd. Scanning Input System) range in 1994. The 5250 and 6250 models could not only input images into a Mac, but could be largely driven by the Mac. These scanners use sophisticated proprietary software (not a Photoshop plugin). At the same time an upgrade (Magnascans were always very "upgradeable") was launched for older models. This did not include the automated aperture turret and automatic or "memory" focus and enhanced resolutions. It was however extremely worthwhile. It allowed batch scanning, while simultaneously editing "prescan" images. All colour edits could be done on the Mac, and unlimited Setup files (CVs) could be saved.

A few years later the CASC upgrade to the Celsis 5250 & 6250 was launched. This gave automatic (rather than "memory") focus. It removed many of the scanner's dedicated circuit boards, replacing them with software on the Mac. Early models had a dedicated "CRAB" colour processing board installed in the Mac, which was removed when Macs became faster (which in those days meant about 130mhz!).

Crosfield also had an OEM arrangement with Howtek to sell their small desktop drum scanners, which were badged as "Celsis 240". Although quite good in RGB mode, they used no Crosfield software or technology. The CMYK software was of no comparison to the genuine Celsis software. Why Crosfield did not develop it's own small drum scanner is a complete mystery! The general consensus is that the company had lost it's way by then, mainly due to incessant management changes.

A Brief History of Crosfield Electronics Ltd.

John Crosfield formed Crosfield Electronics in 1947 to design and manufacture press control equipment. The first colour scanner, the Scanatron, which used CRT technology, was introduced in 1958. This took up nearly a whole room! The first of many Magnascan drum scanners, the 450, was launched in 1969.

Crosfield introduced the world's first digital scanner in the mid-70's. This was soon followed by Electronic Page Composition Systems capable of combining several images together. These later handled image retouching. Very basic stuff by today's standards but revolutionary in the late seventies and early eighties. Crosfield Electronics Ltd. became part of the large and very long-established De La Rue plc group in 1974. For many years the company was located in Holloway Road, North London. Manufacturing was relocated to Peterborough in the mid-70s. The Head Office and Research & Development department moved to Hemel Hempstead, Hertfordshire in 1984, while the Training Dept. moved to nearby Watford.

In 1997 what remained of Crosfield became FFEI (FujiFilm Electronic Imaging), having for the previous few years been jointly owned by Dupont and Fujifilm. Manufacture of drum scanners ceased around 2003. In the last few years only a handful were built. In the heydays of the 1980s as many as 100 per month could be built in the Peterborough factory. About 85-90% were exported. Indeed the company won so many "Queen's Awards for Export", etc. that the reception area couldn't display them all! The Head Office in Hemel was scaled back to the former R&D building, with the former four floor office block being let to other businesses, and becoming "Catherines House". Manufacturing of platesetters, etc. remained in Peterborough, which was very fortunate, as later events were to prove.

On December 11, 2005 disaster struck in Hemel Hempstead. The adjacent massive Buncefield Oil Depot exploded. This was the largest explosion in Europe in peace-time! The very large Industrial Estate was almost obliterated. More than 40 premises were destroyed or seriously damaged. Fortunately it occured at 6 o'clock on a Sunday morning, so there were no fatalities and few injuries. The former Crosfield building was badly damaged, with the FFEI Head Office being completely destroyed. Apparently this was one of the nearest buildings to the oil tanks. Staff were relocated to Peterborough and to other temporary premises. Later in 2006 FFEI Ltd. had a management buyout from Fujifilm. Some of the best information and photos of the Buncefield disaster.

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Coast Imaging Arts - The Art of Imaging Excellence

2010-12-06T05:30:00.000-08:00

http://www.coastimagingarts.com/

Hasselblad Flextight X1 - Test report and comparison to X5

2010-12-06T03:19:00.000-08:00

http://www.filmscanner.info/en/HasselbladFlextightX1.html

Within its product range, Hasselblad offers two professional film scanners. Hasselblad Flextight X1 is a slightly reduced version of Hasselblads top-model Flextight X5, for which we already certified an outstanding performance in our detailed test report. On this page, we will get into the differences between these two top-scanners and perform some tests in order to see how the Flextight X1 performs against the Flextight X5.

In our test labour, we have positioned both devices beside each other and operated them with two different computers in order to determine some further differences. In this short test, we will exclusively get into the differences between these two scanners so that a possible purchase decision results to be easier. Concerning the basic information about the equipment, installation and the handling of both scanners, we kindly ask you to read it from our detailed Test report of Hasselblad Flextight X5.Both scanners have a very similar exterior appearance. Except the model description which is located at the front side of the devices, they only differ by a small detail in the case: While the X5 has a ribbing at the case flanks, the case of the X1 is completely smooth. Both devices are of the same size. Thus, the differences must be in the interior.

Differences between Flextight X1 and Flextight X5

In what does the Flextight X1 exactly differ from its big brother Flextight X5? Herein, we first would like to provide you with a general view. Thereby, we will observe 8 distinctive features of quality of both scanners; for now, we will discard the exterior differences of the cases as also the significant difference of the purchase price.

1. Resolution

First, there is the higher nominal maximal resolution of the Flextight X5 to be mentioned: Its 8000ppi are compared against the 6300ppi of the Flextight X1. But in practice, this difference becomes quite insignificant.

The respective maximum resolution of both scanners is only available in the 35-mm image format, and the Flextight X5 "only" achieves an effective value of about 6900 ppi in a scan resolution of 8000ppi. Thus, the difference in the effective resolution that is possible to achieve between the X5 and the X1 is of 6900ppi against 6150ppi. Both of these values are so extremely high that they exceed the resolution limit (grain boundary) of a 35-mm film.

Thus, the difference in the resolution is rather nominal, as in case of the medium and the large formats, there is no difference in the resolution of both devices. Therewith, the resolution criteria can be omitted as a real differential factor and should not have any influence in the purchase decision.

2. Maximum density, range of density

Both of the scanner models have a different maximum density: While the Flextight is still able to capture the film details of a maximum density of D=4,9, the maximum density of the X1 is of D=4,6. Therewith, the range of density of the X5 is approximately one aperture stop higher than the one of the Flextight X1.

The higher maximum density of the Hasselblad Flextight X5 means that in extremely dark image areas, the differences of brightness can be still captured while other scanners only represent the colour black. But herein, there is to mention in advance that during our tests, we could not determine in the case of any slide any differences in the dark areas of the scans done with the Flextight X1 and the ones done with the Flextight X5. Therewith, the density criterion also does not seem to be really decisive for the purchase in the comparison between both devices, but of course it is in comparison to other scanners.

3. Scan speed

According to the data sheets of the film scanners of Hasselblad, there is a huge difference in the scan speed between both devices: While the Flextight X1 provides a speed of 60 MB / minute, the Flextight X5 offers a speed that is 5 times faster which is 300 MB / minute.

This speed difference is clearly noticeable in practice, as recorded during our speed measurements. But in a straight comparison of both scanners, the factor value of 5 is not achieved but, depending on the image format, a value of about 4. This is due to the reason that during our measurements, beside the mere scanning times, the time of the film feeding is also included; in both scanners, these times are the same.

Thus, both Hasselblad scanners differ significantly in the scan speed. This is a significant and decisive distinction feature for the purchase. Those who want to scan large amounts will need a Flextight X5 in order to achieve a high productivity and capacity. But those who only occasionally need a high quality scan will also wait some minutes more until the image file is ready.

4. Compatible film formats, film adapter

Both scanners of Hasselblad practically do not differ from the exterior so that one could assume that both scanners can process the same film formats. The Flextight X1 can basically process all film formats that can be also processed by the X5, thus 35-mm films, medium formats 120/220, roll films and large formats up to 4x5". For both devices, the film adapter is identical.

But additionally, with the Hasselblad Flextight X1 it is also possible to scan large formats of 13x18cm (5x7"). This is not possible with the Flextight X5 - the light condensator that is built in it impedes the scanning of such a large film format. Therewith, the Flextight X1 does offer a decisive advantage against its big brother, specially because the large format of 13x18 cm is widely used.

5. Scans of non-transparent material

The scans of non-transparent materials can be digitalised with the Hasselblad Flextight X5 up to a format of DIN A4 (21 x 29,7 cm). This function is not available in the case of the Flextight X1, as this model only scans transparent materials. But it is easy to abstain from this feature, as on one hand, the scanning of non-transparent images/documents with the Flextight X5 is quite laborious and on the other hand, the achievable scan quality is not better than the one that results by using a high quality flat bed scanner that only costs a fraction of that what a Hasselblad Flextight costs.

6. Accessoires for the batch processing

For the Flextight X5, Hasselblad offers two feeders for the batch processing: a slide feeder for up to 50 framed 35-mm slides and a batch feeder for up to 10 film adapters of any type. With the first one, it is possible to scan up to 50 framed 35-mm slides in the automatic modus without any intervention of the user. In the latter, it is possible to insert up to 10 different film adapters so that the Flextight X5 processes up to 10 film patterns in the automatic modus. Thereby, it is not necessary that the 10 film adapters are of the same type but different formats can be mixed together.

With the Flextight X1, the use of such feeders is not possible; this device does not have any connection for these kind of accessoires. Thus, those who have large amounts of film material to process should not only choose the bigger Flextight X5 just because of the higher scan speed but also due to its expandability of the feeders.

7. Cooling of the sensor

Either the structure of the Flextight X5 as also the one of the X1 have some heat reducing features, as for example the externally arranged power supply and the appliance of a cold-cathode fluorescent tube as a light source. Moreover, the X5 additionally offers an active sensor cooling that continues reducing the image noise caused by the heat. But this is not significant until the device has been continuously used for several hours without any break in between the scanning procedures, thus specially if the optional batch feeding procedures are used, or if one works with several film adapters so that the scanner is continuously working.

The missing sensor cooling does not have a negative effect in the case of the Flextight X1, as this device does normally not work continuously. But in the case of the Flextight X5, the sensor cooling is absolutely necessary, as the device is specially made to perform a high capacity, thus for the permanent processing.

8. Light source

Compared to the Flextight X1, the Flextight X5 has a fixed installed light condensator located straight in front of the light source that disperses the light and therewith provides a soft illumination. Thereby, the smallest scratches and dust particles are outshined, a thing that eases a little the scan preparation concerning the cleaning of the film material and the post-processing concerning the photo retouching. For the scanning with the Flextight X1, the previous and thorough cleaning of the film material before the scanning is much more important as it is in the case of the Flextight X5, as every dust particle on the film is visible.

A straight comparison of the image results of both scanners gives a further insight of the effects of the harder light: The Flextight X1 makes the film grain clearly outstand. Depending on the texture of the grain, a more or less visible snow grain appears. Due to the hard light of the X1, the eventual deficiencies of the original material are mercelessly brought to light, a thing that is not necessarily a drawback. Such a high-definition reproduction can be absolutely wished. The raw scans of the X5 appear to be a little softer than those of the X1, and partly also a little less sharp.

Thus, the Flextight X1 provides some luscious, sharp scans, while the Flextight X5 provides some softer and slightly less sharp images. Which variant is the best is rather a question of taste than an objective criterion of quality. In the following, we will observe the image quality as also the scan speed of the Flextight X1, also in comparison to its bigger brother Flextight X5.

The image quality of the Hasselblad Flextight X1

In our Test report of the Flextight X5 we have shown that the top-model of Hasselblad, the Flextight X5, provides an excellent image quality. Further above on this page, we have listed the differences between this device and the Flextight X1 tested here. Some also have an effect on the image quality. In the following, we will examine this.

Let us start, as usual, with the resolution. As already mentioned, the X1 does not have the "HiRes" modus for 35-mm image scans with 8000ppi. 6300ppi as the highest resolution. In our resolution test with a USAF-1951 test chart, it is barely possible to distinguish the horizontal lines of the element 7.1 and the vertical lines of the element 6.6. Therefrom, the same effective resolution results for the Flextight X1 as the one of the X5, that is 6150 ppi.

In case of larger image formats, the maximum resolution values do not change: For the medium formats 120/220, there are 3200ppi available, and the large format 4x5" can be digitalised with maximum 2040ppi. The measured effective resolutions correspond to the ones of the X5. Thus, with some effective 6900 dpi, the Flextight X5 can achieve, compared to the 6150 dpi of the Flextight X1, a resolution that is 10% higher in the field of the 35-mm images; but this difference has no effect in the practice, as in the case of such a high resolution, the grain boundary of a film is exceeded long ago. The resulting conclusion of this is that concerning the resolution, the small Flextight X1 is equal to the large Flextight X5.

The Hasselblad Flextight X1 has a maximum density of 4,6, while the bigger brother achieves a value of Dmax = 4,9. But despite of the slightly low maximum density, the Flextight X1 provides the same good results as its bigger brother. The lights and the shadows also provide enough definition even in case of an extremely high image contrast. The difference of 0,3 in the maximum density did not have any effect in our tests. Only the tonal value curve from some very dark images of the Flextight X5, in the very left area, one recognizes some more deflections than in the ones of the Flextight X1. But in practice, the difference is not noticeable. Therewith, we can assume that concerning the range of density, both of these scanners are equal and also on a high level of quality.

What is interesting is the difference in the image effect of both scanners that results from the different quality of the light source: The light of the X5 that is soft due to the firmly installed light condensator makes the film grain to appear less dominant as also makes the smallest scratches and dust particles disappear.

This can be seen very well in our first comparison image that enlarges as soon as you click on the thumbnail shown here. Thereby, the image switches approximately any three seconds between the scan done with the Flextight X1 and the one done with the Flextight X5. The image is a 100% outcut of a medium format that was either scanned with the Flextight X1 as also with the Flextight X5. The dust particles of the test slide are clearly more visible in the scan done with the X1, and the film grain is also more strongly marked.

Here, the light condensator is missing in the X1 that provides a very hard and focussed light, the way we know it from the LED light sources, so that every imperfection on the original film, no matter how small they are, are shown: Depending on its texture, it appears more or less visible but always in a high definition and even the smallest scratches, dirt and dust particles are mercessly scanned.

Due to this difference, the scans done with the Flextight X1 appear always slightly sharper than the ones made with the X5. As an example for this, please look at the second image sample which is also a 100% outcut of a scan that is also done with both scanners. But in any case, it should not be understood that the scans of the X5 are not sharp. The X1 only provides a little bit more of sharpness. If this shlight blur effect of the X5 is to be considered as an advantage or a disadvantage depends on the desired final result.

But again, in the noise behaviour of the X1 that in theory should differ from the one of the X5 due to the missing active sensor cooling, we could not determine any difference between both scanners. Also during the test scan of 15 slides of the medium format 6x6 that had been accomplished in immediate succession, in the case of the X1, no image noise was caused as a result of the heat. We assume that the cooling system of the Flextight X5 does not unfold its effect until it is used in continuous operation during the whole day with a feeder.

It can be generally said that the Hasselblad Flextight X1 provides an excellent image quality which can compete without any problem in practice with the top model Flextight X5. Both scanners only differ in the image impression: While the X5 represents the details in a pleasant, slightly soft way, the X1 also toughly represents the finest structures as the film grain and the dirt.

The scan speed of the Hasselblad Flextight X1

Hasselblad announces the scann speed of the Flextight X1 with a value of 60 MB / minute. Compared to the Flextight X5 which has a speed value of 300 MB/minute, the Flextight X1 is therewith clearly slowlier. This huge difference in the speed can be also easily measured in practice. The actual scanning times can be taken from the following table:

Procedure	Duration
Transparency scan of a 35-mm image with a resolution of 2000ppi	1:00 min
Transparency scan of a 35-mm image with a resolution of 5000ppi	3:47 min
Transparency scan of a 35-mm image with a resolution of 6300ppi	6:29 min
Transparency scan of a medium format 6x6 with a resolution of 1600ppi	1:33 min
Transparency scan of a medium format 6x6 with a resolution of 3200ppi	5:14 min
Transparency scan of a large format 4x5" with a resolution of 1020ppi	1:27 min
Transparency scan of a large format 4x5" with a resolution of 2040ppi	4:38 min

The scanning times where detected with the same computer that we also used for the speed test of the Flextight X5: a Windows 7 64-Bit computer with an Intel Core i7 processor and 8GB RAM. With this hardware, which was a high quality hardware at the time the test had been performed, it was possible to make use of the full speed capacity of the scanner and not to thwart it due to a data processing that is eventually much too slow.

By comparing the values of the Flextight X1 and X5, the resulting speed factor is of about nominal 4; nominally, Hasselblad announces a difference value of the factor 5. The resulting factor reduced by 1 is due to the reason that in our measurements, we consider the total time of the scanning including the transporting time of the film that is equal in both devices.

Purchase decision Hasselblad Flextight X1 or X5

Both film scanners, either the Flextight X1 and Flextight X5 are absolute top-devices which really deserve the name High-End-Scanner. In our Film scanners ranking list they deservedely occupy the first and the second place. Both devices convince with an absolute top-quality of image, a high processing quality and a high flexibility concerning the scanneable material. Those who decide to purchase a Hasselblad scanner will be rewarded with an excellent image quality that cannot be achieved by any other scanner. There are currently no better film scanners than these two devices of Hasselblad on the market.

The question that still remains is which of these two models of Flextight is the right one for one. Concerning the image quality, both devices only differ insignificantly from each other. While the Flextight X1 provides some scans which are a little more sharp and luscious, the image results from the Flextight X5 are softer and with less dust particles and scratches. The choice between these two devices is purely a matter of taste. In case of the Flextight X1, the film cleaning previous to the scanning is of a more important role than in case of the Flextight X5. For cleaning the film material, the use of an Anti Dust Spray as also some special Film Cleaning Devices is recommendable.

A decisive criterion of choice for the Flextight X1 is the possibility that it offers to scan large formats of 13x18 cm (5x7". In case of Flextight X5, the normal size of 4x5" possible.

But the decisive purchase criterion for a Flextight X1 or a X5 is the speed: The Flextight X5 is absolutely designed for the fast processing of large image quantities. The scan speed of the Flextight X5 is higher as the one of the Flextight X1 by a factor of 4. In case of the Flextight X5, the active cooling avoids the noise effects caused by the increase of heat, even in the case the device is continuously used throughout the day. And due to the expandability of the optional feeders, it is even possible to work in a real batch processing with the Flextight X5.

Last but not least, the purchase price is also a decisive purchase criterion: The Hasselblad Flextight X5 costs about 7000 € more than its little brother. Therewith, the purchase criterion can be shortly resumed: Those who occasionally need an extremely high-quality scan will be perfectly served with the Hasselblad Flextight X1. But those who need a large quantity of films to be digitalised on a daily basis should get the fast X5.

Conclusion

The Hasselblad Flextight X1 is a scanner that provides an extremely high image quality that is located at the level of the top-model of the Flextight-series, the X5. While the Flextight X5 provides a soft focus effect due to the permanently installed light capacitor which reduces the film grain and dust particles, the Flextight X1 provides the highest possible sharpness of details that makes them clearly outstand. What is preferrable depends on the personal preferences and/or the desired results.

Thus, the Flextight X1 is recommendable for all those users who need the highest possible image quality but for which a high capacity is not a criterion. Those who want to scan some film material of the large size of 13x18cm can anyway only choose the Flextight X1.

Nikon LS-2000 and EverSmart Benchmarks

2010-12-06T03:00:00.000-08:00

http://www.marginalsoftware.com/Benchmarks/ls2000andES.htm

The following images were scanned on a Nikon LS-2000 and a Scitex EverSmart Supreme as possible benchmarks. Since both have more than adequate resolution, the intention was to display the effects of noise, D-max, and flare. These images were among the few that were exceptionally difficult for the LS-2000 to scan.
Original images shot on Kodachrome 64. Images adjusted for contrast and color balance only. Some spotting was done to remove dust. Building images shown without sharpening.

Nikon LS-2000 (downsampled from 1500 dpi)

16x sampling effectively suppresses noise.

EverSmart (downsampled from 1500 dpi)

Below. LS-2000 scan tonally adjusted to enhance flare

Below. EverSmart scan tonally adjusted to enhance flare

Below. Detail at original resolution

LS-2000

EverSmart

Below. Tonally enhanced to display effects of flare.

LS-2000

Eversmart

Below. Scanned on the LS-2000 60% USM applied.

Below. Scanned on the EverSmart. 60% USM applied.

A Comparison of CCD and Drum Scanners for Novices

2010-12-06T02:47:00.000-08:00

http://www.marginalsoftware.com/Scanner/Scanner_Intro.htm

A Comparison of CCD and Drum Scanners for Novices

Photography has been a hobby of mine for over two decades. Along with a professional involvement with computers, it was only natural that this hardware freak would eventually buy a scanner, the first of which was a Nikon Coolscan I. In the days before the Web and devices that could competently display the Coolscan's output, it was little used other than for recording my photography and for personal enjoyment. The Web and the Epson Stylus printer changed all that. Scanners, PCs, digital cameras, and snapshot capable color printers are now offered as mass-market items. A visit to the imaging department of a magazine publisher in New York reflects how radical changes in the mass-market can eventually drive technological developments in the high-end: off-the-shelf Macs and software have replaced specialized graphics workstations; Epson printers are being evaluated as replacements for expensive dye-sublimation printers; and networks enable rapid and widespread access of editorial material. When it comes to scanners for publishing, however, drum scanners are still the technology of choice.

If, like me, your involvement with digital scanning is as an avocation rather than as a vocation, you may have heard or read that drum scanners provide the ultimate in scanner performance. The most common technology employed in consumer scanners is the charge-coupled device (CCD). Few people, however, have had the opportunity to compare directly CCD and drum scanner output side-by-side. After a couple of friends asked me about the difference in results between the two technologies, I decided to put pictures scanned by these types of machines on the Web, kind of as a public service. My point is to demonstrate to users of consumer-grade scanners that the major area of potential improvement for generating quality scans lies in increasing density range.

Charge-Coupled Device Scanners Versus Drum Scanners

Scanners Used

As a representative CCD scanner I chose a Nikon LS-2000. The drum scans were performed on a Linotype-Hell ChromaGraph S3900. Why did I choose these devices? Mostly by default: an LS-2000 sits on my desk at home; the company where a friend of mine works has a variety of flatbed and drum scanners, but since they have a battery of S3900s, it's easier to get access to one of them.

Scanner SettingsThe Web imposes severe constraints on any author attempting to implement a scanner comparison page. First, when we're speaking of high-end scanner output we're talking big-time files and transmission times. To make retrieval time more tolerable, I've down-sampled and cropped from the full-frame images as much as possible without compromising the comparability of the scans. I've included links to higher resolution picture details for closer comparison. Second, the Web is a mass medium, accessible to users with a wide variety of devices. Most PC monitors are not very capable when it comes to displaying photographic images. Unfortunately there's not much I can do if your video card/monitor cannot display these images. The LS-2000 scans were performed at 8bits/channel and 1200 dpi, well within the limits of its capabilities of 12bits/channel and 2700 dpi. The S3900 scans were performed at 8bits/channel and 1200 dpi, also well within its capabilities.

Comparing the ImagesI've included 2 sample images for comparison of CCD and drum scanned images. These images were chosen as a test of the LS-2000's D-Max, one of the highest for CCD scanners. Other than D-Max, these scans are not representative of the ultimate capabilities of either the LS-2000 or S3900 in particular--the image files required for this would be huge--but of CCD and drum scans in general. Technically speaking, I'm showing how images compare when D-Max is the independent variable. Before clicking to display either image make sure your video card/monitor is set to at least 24-bit color.
For each image, compare the CCD and drum scanner images at 1200 dpi to verify that the drum scanner is better at imaging shadow detail at equivalent resolutions. Next, display the same CCD scanner image detail at 2700 dpi. There is a slight improvement in quality over the 1200 dpi image, but it is still not nearly definitive as the drum scanned image. This demonstrates that doubling resolution fails to improve quality sufficiently to compensate for the drum scanner's higher D-Max at 1200 dpi.

Midtown

Downtown

DiscussionTake my word on this, the two drum scanned images closely approximate the slides when viewed on a light table. They would have been dead on if more of the S3900's bit depth and resolution had been used. You might also notice that even at 1200 dpi the S3900 starts to resolve film grain, because of its very high density range and absence of noise.
By the way, did the drum-scanned images look dull and muddy? It's possible your monitor, even though the video card is set to 24-bit color, can't hack showing high quality images created by a drum scanner. That's no insult; it only highlights the essential problem of using drum-scanned images: few consumer level devices can handle the long tonal ranges producible by drum scanners.
Although the drum scanner images contain more shadow detail, that doesn't necessarily make them esthetically more pleasing or more effective at expressing the photographer's vision. Remember the Christmas pictures of the family sitting on Aunt Emma's sofa? Is it really necessary that the sofa's plaid pattern show up in your prints? And if you scan for increased resolution, will your final output device be able to make effective use of it?

The Drum Scanner OptionWhere critical scanning and volume are an intrinsic part of business operations--in publishing, engraving, and fine arts--it makes sense to own a drum scanner. For the majority of us who dabble in imaging, a competent CCD desktop scanner will fulfill the vast majority of needs. Personally, I would use a drum scanner for badly exposed shots, larger format film, posters, and archiving of fine art. For these exceptions, it's sufficient to have recourse to a service bureau that performs drum scanning.

SummaryThe drum scan images, when compared in detail with CCD images, show how good scanner technology could be if more emphasis were to be on improving D-Max. In addition, it makes little sense to do this in isolation without improving monitors and printers in parallel (as you possibly may have seen when you tried to display the pictures). Hopefully this effort will modestly change the way consumers evaluate scanners and ultimately drive the design process of scanners.

AcknowledgementsI would like to thank Janet Miller of Time Inc. and Brad Pallas of Hachette-Filipacchi Magazines, Inc. for their assistance. Austin Franklin of darkroom.com and Phil Lippincott of AZTEK, Inc. graciously contributed by explaining the distinctions between "density range" and "dynamic range".

DRUM SCANNING RESOLUTION

2010-12-05T17:26:00.000-08:00

http://www.dannyburk.com/drum_scan_resolution.htm

Drum scan resolution is unsurpassed for sharpness and contrast range. Seeing is believing!
Here are some actual UNRETOUCHED drum scan clips. Note that they have not been altered in exposure,
saturation, sharpening, or sizing: they are clips that I've taken directly from an actual drum scanned 4x5
transparency (Velvia 100F). Below the clips is a large (1200 pixels in height) illustration of the entire 4x5,
with the red box indicating the area seen in the 2000 dpi clip.

Like any scanned or digital image, a raw drum scan will always appear soft, requiring proper sharpening for
the final result. Remember that these clips are UNSHARPENED (the full-size image has been sharpened for
web viewing), but the minute detail that has been captured can easily be seen even in this unsharpened form.

The clip above is from an unretouched 2000 dpi scan. The original transparency is extremely sharp and
detailed; note that individual leaves and blades of grass are clearly visible in the scan, even though these
trees were about 1/3 mile from my camera position. (A 450mm lens was used in 4x5 format.) If your monitor
is set at a resolution of 1024x768, you are viewing this clip as it would appear in a print of about 8x10 FEET
in size!

Even higher resolution. This clip is an unretouched sample at 4000 dpi. At this resolution, the clip is comparable
to what you would see in a print of about 16 x 21 FEET in size...and remember that it hasn't been sharpened for printing.

Frost-covered trees, Lake of the Clouds, Porcupine Mountains State Park, Michigan

Here is the full image, sized to 1200 pixels along the long side. It has been sharpened for web viewing.
The red box encloses the area shown above in the 2000 dpi clip. With this scan, I can create large,
incredibly detailed prints: my 4000 dpi scan will print at about 45 x 56 inches (at 360 dpi) with no
interpolation. (Side note: be aware that the trees in the above image are coated in thick frost,
which accounts for their pastel appearance; the image is not washed out!

Scanner Comparison - Epson vs Imacon vs Howtek

2010-12-05T17:04:00.000-08:00

http://www.timparkin.co.uk/blog/scannercomparison

Scanner Comparison - Epson vs Imacon vs Howtek

I've posted previously about a comparison between drum scanners and Epson flatbeds. The fact that the drum scanner trounced the Epson was not really in contention but recently I had the opportunity to get a scan from a modern Imacon scanner (owned by Joe Cornish) and from a Howtek 4000 drum scanner (re-badged Crosfield Magnascan 200i I believe, and owned by Dav Thomas) using Silverfast Ai v 6.6 & Kami SXL 2001 fluid both using the same transparency that I had previously had problems with using my Epson.

I knew that the drum scanner was going to provide a better resolution scan than the Imacon but I was more interested in how well it scanned shadows and was it immune to some of the artefacts that I'd seen from the Imacon and the Epson. These artefacts were halation and chromatic abberation.

Halation, a glow around high brightness areas that impinges into darker areas. I have seen a small version of this, a few pixels on a 2000dpi scan, and also a larger version that spreads 2-300 pixels. In photographic terms this is similar to flare and I imagine it occurs in a similar fashion. In the example scan you can see this in the area around the cliff edge and also at the top of the worms head island.

Interactive Example of Halation

Chromatic abberation is evinced as a red and blue borders at opposite sides of a high contrast edge. In the scan you can see this the worst around the white lichen hot spots at the bottom left of the picture but it can also be seen at the top right of the cliff top and also as a strange colouring in the sea where you have a highlight off the wave top right next to a shadow from that same wave. The image at the top of this post shows one of an example of this.

Interactive example of Chromatic Abberation

In comparing these results, it should be kept in mind that the drum scan took 5 mins of mounting and 1.5 hours of scanning wheras the Imacon took 5 minutes to do both.

Here is one of the clearer examples which shows what happens if you want to pull detail out of shadow areas..

Interactive Example of pulling shadow detail - look closeley at the twig bottom left

Click on the many links on the left hand side of the Interactive Example to see more crops.

In conclusion it seems that the best way to scan images is to get a drum scanner. However, there are many other factors at play here. Wet scanning is messy and a lot of people are uncomfortable exposing transparencies in this way. Also, the whole process is a lot more time consuming. Finally, the amount of room a drum scanner takes up can be 10x as much as an Imacon. Realistically, if you want to scan more than a couple of photos a month and you have the budget, an Imacon will always be a better choice. However, for those with limited budgets, excess time and who only process a few images a month, a drum scanner will produce stunning results.

If most flatbed scanner ads try to compare their scanners with the quality of a drum scanner, don't you wonder why a drum scanner is so much better?

2010-12-05T16:32:00.000-08:00

http://www.flatbed-scanner-review.org/flatbed_scanner_drum_scanner_li/drum_scanner_quality.html

If most flatbed scanner ads try to compare their scanners with the quality of a drum scanner, don't you wonder why a drum scanner is so much better?

Clearly a scan from a drum scanner is superior in almost all respects. This should be qualified relative to entry-level drum scanners which use CCD sensors. Several companies have repackaged flatbed scanners to resemble drum scanners in physical shape and appearance or in their specs as touted in PR.

Ian Smith, at that time of ICG as Global Graphics, now handled by DCS Associates and ColourPeople. Ian is seen here many years ago either at DRUPA 2000 or Photokina of that year. He has been with the ICG scanner all these years. This continuity means you are assured of knowledgable tech support today in 2004.

To make matters worse, some of these camouflaged flatbed scanners were overpriced to make them resemble drum scanners all the more.

In summary, if you want the absolutely best scanner, then your best decision is a full-scaled drum scanner. The former Crosfield scanners now manufactured by Fuji would be one good choice for an industrial strength drum scanner. Heidelberg makes a top of the line drum scanner.

My personal choice in drum scanners would be the drum scanner models from ICG shown at left because I dislike the idea of having to put oil on my transparencies. The FLAAR Photo Archive chromes are relatively fresh, most have never been used (or abused), and hence do not have enough scratches to warrant oiling to reduce such scratches. The ICG drum scanners offer a slot system so you can insert the transparency without any liquid. I also dislike the need of cleaning up the poor transparency after this whole process (in part because I have 40,000 transparencies that would need to be oiled, and then cleaned). ICG makes a system whereby you can do a drum scan without oil. Nonetheless, you will actually get better results if you do use oil. Even on a flatbed if you oil the slides the resultant scan is better. This is why Creo offers an oil mounting station for their high-end flatbed scanners.

Dust is present on all slides and negatives, even those fresh from a darkroom (good old static electricity is to blame here). The drum scanner focuses just on the film plane and thus may miss the dust which is on or above the surface of the transparency. Also, when you clean the transparency and apply the oil, the dust and scratches disappear. It is faster to prepare and load a drum scanner (and not have to erase dust and scratches later in Photoshop) than it is to do a flatbed scan and then waste 30 minutes to an hour using a rubber stamp tool in Photoshop to cover over the blemishes.

Sure you can automatically remove dust and scratches with software, but that maneuver also removes some of the quality. Removing dust also takes time. In other words, a drum scanner may be more cost effective.

Whereas monumental specs are always impressive, it is the final results, what the image looks like to the viewer (and especially to the client) which count. In other words, 10,000 dpi may not be seriously necessary, but it is surely nice to have more than the 1200 dpi of mid-range flatbed scanners. Besides, there is no XYZ stitching with a drum scanner. You get the full dpi that you selected (usually 3000 dpi and up).

But again, beware of low-end drum scanners, of repackaged CCD scanners, and other claims of "drum scanner quality."

After all, the only scanner that can truly produce drum scanner quality is a quality drum scanner. Fuji and ICG are a good place to start. A drum scanner from Heidelberg should certainly be expected to be of professional quality. I do not have experience with Screen USA (Dainippon Screen) but they are a respected name in the prepress world. The only drum scanners that we are not overly enthusiastic about are those of Howtek. Nowadays a good flatbed scanner from Creo , such as a Creo EverSmart Pro II or especially the Creo EverSmart Supreme probably produces a better scan than a Howtek. If you want a drum scanner, might as well get a really good one, namely an ICG drum scanner. After all, if you want a "cheap scanner" you should not be reading these pages anyway. Cheap scanners produce cheap scans, which are probably okay for many users, but we prefer better quality.

If you need help deciding what high-end professional flatbed scanner to select, you cane-mail the main reviewer at FLAAR, Nicholas Hellmuth. Just be sure to specify roughly your needs (what do you scan, 35mm, medium format, 4x5), what is the end product of the scan (posters, calendars, printed, wide format, or whatever), and your realistic budget.

For us to answer you personally, however, please do not ask a question that is already covered in the pages of the web site. Please check out the Directory of all scanner pages, before you contact us.

We would provide a phone number, but the FLAAR crew is either in Germany or Guatemala or checking out digital imaging equipment at a trade show in the USA. You can write in German, Spanish, French, Italian, or naturally English. No, FLAAR does not sell scanners (this is a non-profit institute) but we can definitely suggest reliable sources.

Crosfield 6250 Scanner still in use in 2010

2010-12-05T15:56:00.000-08:00

http://www.youtube.com/watch?v=0y3RdBRED50

Photo Scanner Technology Explained

2010-12-05T15:36:00.000-08:00

http://www.kenrockwell.com/tech/scantek.htm

Photo Scanner Technology Explained
© 2006 Ken Rockwell. All rights reserved.

INTRODUCTION

I forget that most people coming to this site are new to digital imaging.

I've been studying bits and pixels since 1973, and been working with it daily to earn my living at my real job since the 1980s.

Allow me to explain about bits and pixels and DMaxs so they make sense.

Automatic Dirt and Scratch Removal (ICE)

Software alone can't do this as of 2005. Software still fails because software can't differentiate between dirt and a real image element, like a branch, anywhere near as well as our eyes can.

The founder of Applied Science Fiction, now a part of Kodak, had the brilliant idea to use a fourth infrared (IR) scanning channel, in addition to the usual three red, green and blue channels. Color film is transparent to IR, and dirt and scratches are not. BRILLIANT! The scanner knows what looks black to the IR sensor is a film defect.

Locating the dirt is the hard part. Once that's done it's easy to fill in the dirt and scratches automatically with software that patches over the known bad areas.

Because the film's image has to be transparent to IR you cannot use ICE on traditional silver B/W film. Traditional B/W film's silver is as dark to IR as it is to light, thus if you're a wise guy like me and try it you'll get totally soft highlights since the scanner will think all the dark parts of the negative (the highlights) are all scratched and the software will try to patch (smear) all over them. Remember B/W film's image is made with silver, which is why B/W film and prints last forever since metal doesn't fade away. Color film and images just use dye which all fade in time.

Thus ICE works great for color negatives and slides but not B/W. It should work on chromogenic B/W films that process in C-41 color negative chemicals. Ignore me, read your scanner's instruction book and try it. It is not supposed to work on Kodachrome since Kodachrome's dyes are also somewhat opaque to IR. I have not tried it. A reader writes in July 2005 that his Minolta 5400-II works great with Kodachrome; I haven't tried it.

In fact, today the best way to shoot B/W for digital is to shoot it on color film since 1.) ICE works and 2.) you can choose the mixing of the color channels in Photoshop to select the effects that in the old days you had to do before making the image by choosing a colored filter to put over the lens. In the old days I would sometimes shoot several images with different filters; today I just shoot it once on color film if my output is to be B/W digital.

It takes about three times as long to make a scan with this feature turned on. It saves you more time than that since you no longer have to spot the scan.

I like the way ICE works on the Nikon LS-2000 and LS-4000, but on the LS-30 it seems to dull the image. People have differing opinions on this feature.

I wouldn't buy a scanner for 35mm unless it has this feature.

It does not soften the image, but it may take some little one-pixel bites out of sharp lines. I usually use ICE, although if the image has no broad areas where dirt would be obvious I may turn it off to save scan time.

Canon's FARE system on the 2400 flatbed is awful. It replaces dirt with big blobs and erases other parts of the image. I found it to be useless except in broad sky areas, where Photoshop's dust filter also works perfectly. Use FARE on a slide with any detail in it and you will see all sorts of screwy artifacts once you learn what they look like.

Light Sources (LED vs. Cold Cathode Fluorescent)

Don't worry. The scanner makers worry about this so you don't have to. A scanner's performance depends on many, many, many factors and the interaction among many more factors. The key determinant in a scanner's performance is the designer's ability to balance these many factors to give the best performance at any price level. Yes, even $100,000 scanners have to make engineering compromises, thus any scanner's worth depends on how clever the engineers were at making good choices.

Don't be distracted by what kind of light bulb it uses or what brand of lens or any of that.The only way to determine the scanning ability of a scanner is to make some scans and look at the images.

Resolution, DPI, Definition and Image Structure Defined

These are all very different terms.

Resolution are the finest details between which a scanner can see. In other words, the scanner needs to be able to resolve the difference between very close together image elements.

Some film scanners are so sharp they can see details smaller than the size of a pixel. This is called "aliasing" or "false resolution." It can lead to emphasizing grain from print film. It also allows scanners to see details finer than their image structure (defined below). This is beyond what I feel like explaining here, but suffice it to say that even though one can see details finer than the pixel structure that they are misrepresented in the image and no longer look a fine as they do on the original. They look like Moire patterns if you are looking at test charts, or extra grain if you are scanning negatives. This usually only happens at the lower resolution settings of a scanner if the designers decided not to go to the efforts of doing the proper Nyquist anti-aliasing.

Most people and manufacturers erroneously use the term "resolution" when they really are referring to the image structure, or the number of pixels in an image defined below.

For instance, DPI or dots per inch, referred originally to the the ability of phototypesetting image setters to write small details and smooth looking type. Today this phrase refers to how many pixels one has, which is image structure (defined below) and not resolution.

Definition is a subjective term referring to how sharp something looks.

Image Structure refers to how many pixels an image has. All because an image has a certain number of pixels does not mean that all these pixels are different and can differentiate detail, or resolve parts of the image. For instance, it is trivial for scanners and cameras to add meaningless pixels as explained elsewhere. This adds to the number of pixels but does not add anything to the resolution or definition.

Resolution and phony pixels

"Real" pixels are real pixels.

Phony pixels are made in several ways. Many scanners and digital cameras add pretend pixels in between the real pixels to help make an image smooth and not pixely when enlarged, however they do not add any sharpness or detail.

All scanners can add phony pixels when set to resolutions above their legitimate optical resolution. Digital cameras do this when set to larger (but bogus) "recording resolutions" or "interpolated resolutions." You can do this yourself in a program like Photoshop when you resize the image and have "resample" box checked.

For scanners and digital cameras these claims are simply lies on the parts of the manufacturer and they are rampant today. Altimira's Genuine Fractals does the same thing: it makes pretend pixels and eliminates the obvious boxy pixely look, but does not add any more detail to your image as you enlarge.

Make very sure you are trying to compare legitimate resolution to legitimate resolution among scanners. Always ignore the larger of two numbers, for instance, a 2400 x 1200 DPI scanner is just a 1200 DPI scanner, and just forget about any "Interpolated" resolutions. Those are meaningless.

DMax

Dmax is the maximum absolute density of a piece of film. Velvia goes to almost 4.0D in its blackest blacks, the deepest black in any color film. Most slide film only goes to about 3.5D.

Color and B/W negative films only go to about 1.4D perfect negatives, and in even heavily exposed ones almost never over 2.0D, so DMax has no importance for scanning from negatives.

D range is the range between light and dark. Since 4x5" and 120 transparency film usually has a Dmin (clear area) of about 0.05D then a scanner with a Dmax of 4.0 really only would have a D range of 3.95.

As you can see, it looks better to spec Dmax and not D range. Dmax is the hard one to get. Only an idiot designs a scanner not to be able to scan to 0.01 D min.

D range is a more meaningful spec than D max, and here's why: Remember that marketing departments may choose to measure Dmax with the analog gain or the light bulb turned all the way up, in which case you can see into deeper blacks, but will lose the highlights. You have to read and ask carefully, everyone lies differently. If you see a spec of Dmax 4.2 and D range 3.9 that means that the D max of 4.2 is really a hoax. It means you really can't get to D max of 4.2 unless your highlights are dull gray at 0.3D. The only way a scanner like that gets to see 4.2D is by turning up the light bulb a stop and blowing out highlights at less than 0.3 D. With a decent transparency this hypothetical scanner really only has an effective D max of 3.95, with a D min of the good transparency probably 0.05D.

Here's more reasons to ignore a D max spec: What does the scanner do at that density? Does it have a 20dB signal-to-noise-ratio, or is that where the noise completely covers the data from the film? Is that the quiescent noise level of the scanner, or can one still see clearly what's on the film? Since no one in CCD land specs the criteria on how they determine their Dmax spec they are all meaningless.

Grasp as we may for meaning from specifications, the only way to know how well they can be made to scan is to try for yourself with a dense example of a Velvia transparency. For instance, I tried both a $300 Epson 1640SU photo (3.0 Dmax spec) and a $1,500 Microtek Artix 1100 (3.9 Dmax spec.) The two were about the same, and in fact, the noise from the Microtek was nastier because it caused visible streaks. Microtek claimed that that scanner was defective, and I have not tried other samples. I tried the same dark night Velvia transparency on those two scanners, as well as a Nikon LS-2000 and Coolscan III LS-30 and Kodak Photo CD. They were all subtly different, but nowhere near as different as the D max specs of these scanners would lead you to believe. Maybe if you are all very good (and you have been) and I get very bored I'll just post the results up here for you all to see.

Scan Times

Don't believe what the manufacturer says. Most scanners will take several minutes to scan whatever it is you want to scan. Manufacturers lie about the scan times by specifying the times at a lower resolution and for a smaller image then you will be scanning, and then lie about that, too.

The Myth of 42 or 36 or 14 or 16 Bit Scanning

You can safely forget about how many bits (8, 10, 12, 14 or 16 per channel, or 24, 30, 36, 42 or 48 bits per sample) a scanner claims to have. These have nothing to do with how good your scan will look.

The illustrations on the boxes of some Microtek scanners and sales literature for theMinolta Multi Pro are complete lies, plain and simple.

Color depth has nothing to do with shadow detail or color accuracy.

Yes, you can see more shadow detail in the illustration at the Minolta link, but that's because Minolta is deliberately deceiving you by having played with the same image in Photoshop to lighten one! In court Minolta would plea that those images were for illustration only and that they were manipulated only to allow the differences to be more visible and were not intended to deceive. Sure.

If you prefer to believe a salesman or your hobbyist friend who is an engineer in some unrelated field, fine, but if you want to listen to someone who does this for a living or can believe your own eyes read on.

Even the dumpiest scanners today brag about 42 bit scanning. That means that they use an analog-to-digital converter that just happens to have 14 bits coming out of it to digitize each of the signals from the analog outputs of the CCD preamplifier for each of three color channels (red, green and blue.)

If this sounds technical, it is. If this makes no sense to you, that's my point. I used to work where we made the A/D converters for all the world's best scanners and I can, and probably will, explain this in excruciating detail someday. What is important for you to know is that there are so many factors that relate to scanner quality that the number of these internal bits alone is completely insignificant. Skip to the end of this section for the real answer if this gets too technical.

Last years models were 36 bits (12 bits per channel) and the year before that it was 24 bits (8 bits per channel).

Let's explain why more bits are better, then I'll explain why this make no difference on scanners in the under $3,000 price range.

We only can see between 6 to 8 bits per channel log (18 to 24 bits per pixel) at best.

The reasons a scanner would like to have more than 8 bits per channel is that is so that one can 1.) convert digitally from linear analog input to log digital output instead of doing the process in analog (in other words, resolve fine differences in the black areas of the image) and 2.) to allow further fine-tuning of an image in the higher resolution so that one still has 8 good bits per channel (24 bits per pixel) after all the image tweaking is completed.

One looses accuracy in every 8 bit Photoshop operation, even though all the bits are still there. Mathematical errors accumulate with every operation, just as you would if you always had to write down your results from balancing your checkbook with only 4 digits. You need 16 bits to represent the product of two 8 bit numbers, so when the answer has to be truncated or rounded or redithered back to to 8 bits you loose something. If you only start out with 24 bits, by the time you get done in Photoshop you have lost a few bits of accuracy due to all the small mathematical errors. By starting with and working with more buts you can easily preserve your accuracy. This becomes critical if you are playing with levels and curves.

Scanning in the 42 bit mode into Photoshop lets you attempt to retain plenty of bits of accuracy even after a lot of Photoshop tweaks. This is good.

Here's the problem: The noise of the CCD and it's circuitry completely cover up any of the precision the A/D converter might have. At best the noise level of a typical scanner is at about 30 bits per pixel, and probably even worse. ALL THE EXTRA BITS ARE DOING IS REPRESENTING NOISE.

If these were $50,000 photo-multiplier tube (PMT) based scanners you might have enough signal-to-noise ratio coming from the image sensor (the tube) to justify a 12- or 14-bit per channel A/D converter

These CCDs simply don't yet have the signal to noise ratio to justify the high-bit ADCs. That's OK, since the ADCs are not likely to be accurate to as many bits as they claim as well.

Therefore, ignore people who work in computer stores and try to get you to believe that more bits are better, and can't even explain exactly what the extra bits do. In this case they mean nothing.

Even worse, unless you are using a pretty hot version of Photoshop, very few computer programs even can read anything other than 24-bit (8 bit per channel) images. Unless you have Photoshop 6.0 you can't do much of anything with 42 bit images, even if you can read them.

The JPEG (.Jpg) format only works in 8 bit mode, for example. If this is your case, the only advantage to more real bits inside a scanner is if the scanner was doing some signal processing in the digital domain in which case more bits could be better.

Hopefully by now I've convinced you that these internal details are meaningless taken outside the context of the entire system design of a scanner. All things being equal more bits are better, however things are so unequal that the number of bits is meaningless.

What is this Drum Scanner against which all other scanners compare themselves? (so you know they're not as good)

Professionals in print shops that produce all the magazines and printed catalogs we read laugh at the CCD-based scanners we photographers use. All the scanners you or I are likely to buy are based on CCDs, the same little chips that you have in your camcorder or digital camera. The only difference is the scanner CCD is much longer than the one in your camcorder (more pixels) and it's only one line that scans across your image slowly to make a complete scan.

Drum scanners spin your film around on a drum while a fixed laser or other beam of light looks at the art as it spins. The beam is them picked up by a very sensitive vacuum tube called a Photo Multiplier Tube (PMT). This big single, fixed tube is much more sensitive to light than any of the teeny-tiny pixels on a CCD and therefore can see a broader range of light from white to black, and also sees it without the noise of a CCD.

Drum scanners are good not because of the drum, but because the image is picked up by a much more sensitive PMT.

The big PMT is a zillion times more sensitive to light (read shadows in slides) than a moving CCD with teeny weeny pixels. This gives far cleaner images right into the blacks of Velvia. The microscopic pixels of the CCD fight for each photon. There are so few that honestly you start seeing the variations of single photons as noise. There are bazillions of photons that hit the huge PMT from the single bright beam that blasts the original, so low noise and cleaner scans are the result.

See Hamamatsu's site for more information here.

A drum scanner beam can be focused as small as you want. You can move the drum really slowly and get almost unlimited resolution.

Drum scanners used to cost hundreds of thousands of dollars, were about twenty feet long and took years to learn to operate.

Today new ones from Aztek start at about $20,000. Heidelberg still makes the $100,000 ones, unfortunately their website is sucky so good luck finding anything. Also look at ICG and Screen. I think you can get used from about $5,000, but beware, I hear these things are a royal pain to operate.

Of course you have to soak the film in oil before mounting the film to the drum, and then clean the film afterwards.

These things run on vacuum tubes so probably always need to be screwed with.

If regular scanners confuse you enough with color profiles and pixel densities, then don't even think about a drum scanner because you have even more new ways to screw up your scans, like selecting the correct scan apertures.

If you want it scanned as well as possible, drums are the way to go.

The Imacon, advertised as a drum scanner because they use a curved film path, is nota drum scanner. It's just marketing people trying to mislead you again.

You send your film out for drum scanning. I intend to try using photographer Mike Strickler in Northern California. Look under "Services" and then under "Digital Services" and then "High Resolution Drum Scanning." Likewise you can try local publishing and printing houses, but be very careful. Print shops can muck up and scratch your film since they're just doing this for commercial printing day in and day out and won't be going out of their way to treat your prized film as you would. I'm hoping a photographer like Mike takes the time to treat our film as carefully as his own.

How to Scan

Dynamic Range Trick for Negatives

If the dynamic range of a negative results in washed out highlights or dead shadows with the scanner set to scan a negative, trick the scanner and set it to positive (or transparency) mode for the scan and then invert it in Photoshop. After this, go into LEVELS in Photoshop and set your highlights and shadows where you want them.

Drum Scanners Vs. CCD Scanners - Is It Worth it?

2010-12-05T15:33:00.000-08:00

http://www.luminous-landscape.com/reviews/scanners/drum_scans.shtml

Drum Scanners Vs. CCD Scanners - Is It Worth it?

"To drum scan, or not to drum scan", is the question I hear often from photographers. I made my decision to buy a drum scanner and have now been using it for almost a year. With this article I will share some of my experiences. This is being written from a photographer's point of view, rather than that of a service bureau operator, and is mainly concerned with scanning film, not reflective materials. And, although drum scanners can scan negative film, it seems that there are problems with color casts. I am told though that with ICC profiling systems in the hands of a knowledgeable person this can supposedly accommodated. However, this article is based on my personal experience with scanning color transparency material, not negative film.

Although flatbed CCD scanners have come a long way in the past few years, in head-to-head comparison they are no rival for a good drum scanner. However, as this article will explain, in certain cases, flatbeds can rival a good drum scanner. The key is to first clearly define your objectives in your scanning. Then, becomes much easier to understand what products and services are best for your needs. Lets explore the pros and cons of each.

The Benefits of Drum Scanning

Resolution:

Drum scanners rule the resolution war, plain and simple. Good drum scanners can resolve 8,000 ø 11,000 dpi optically. But, is all this resolution worth it? The best answer is, "sometimes", It all is dependent on the enlargement factor one is imposing on the item being scanned.

For example, if you are scanning a 35mm transparency and want a 24x30" final print, and you are printing to an Epson printer that produces its best quality at 360 dpi, then the enlargement factor of 24x at 360 dpi = a 8,640 dpi scan. There are no flatbeds I am aware of that can scan at resolutions this high. The new high end flatbeds such as the Cezanne and Jazz range from about 1500 to 5400 dpi; not bad, but a unit that can optically scan at 5,400 dpi is priced around $55,000, so don't always think that flatbeds are a cheaper alternative to drum scanning.

Wet Mounting:

One thing I have learned the hard way is that wet mounting is mandatory for the best scan. All film have small scratches and dust that appear exaggerated when scanning for big enlargement factors. Most scanner makers advise that anything in excess of 2x or 3x enlargement factor be wet mounted Vs. dry mounted. In addition to Newton Rings the detail of the scan is much more obvious under a wet mount.

A wet mount consist of placing a mounting fluid between the film and the drum (which is shaped like a cylinder made out of a highly translucent plastic-like material), and between the film and a piece of clear acetate that is placed over the film. The wet fluid forms a wet-seal between the top and bottom surface of the film. Just looking at this wet-seal over a light box, one can clearly see the improved clarity of the film Vs. looking at film on a light-box without a wet mount. In addition to removing scratches and dust, wet mounts also blend film grain to make it unnoticeable.

This can happen even if film is not enlarged a great deal. Even film like Provia F (the least grainy of film of all) can show grain even in small enlargements. This occurs as a result of overexposures and certain colors that cause the film to display grain under lower than expected magnifications. If you want to see a final wet mount scan Vs. a dry mount scan of the same image, then look here. The differences are quite noticeable.

Most drum scanners in the past used a oil based mounting fluid. Fortunately I learned of a non-oil based product made by Kami which is alcohol-like in consistency. It is very easy to work with Vs. oil-based mounting fluid. This was a major breakthrough in time savings for both mounting and clean up.

Dmax and Dmin :

Without getting into any debates on the subject, scanner makers each rate their scanners on how much latitude the scanner can produce. Drum scanners seem to always outshine most flat-bed CCD scanners in this area. And, I do not want to leave out the fabulous Imacon FlexTight scanners which are not flat beds, and in a class of their own.

The reason I do not like discussing this is that their seems to be no readily available test for the average consumer to determine these values, and there is no single unbiased testing laboratory that publishes these values from their own tests. So therefore the makers of the scanners publish their own values and never seem to be confirmed / denied by any unbiased third parties. So it seems that every scanner is starting to claim values like 3.9, 4.0, 4.1 and some even 4.2, even though the theoretical 4.0 is the highest value possible.

I have not gotten a good explanation of this from anyone. In the actual scan these differences will mainly surface in shadow detail. The best way to determine this before buying a scanner is take a transparency that has a very wide latitude of shadow to highlights and compare the scanner you want to buy Vs. a good drum scanner. If the difference is marginal but the price difference is substantial, then you have the answer you need to make an intelligent choice based on you needs.

Bit Depth:

Bit depth is the number of colors a scanner can capture. And although good drum scanners have 16 bits per channel input for a total of 48 bits, this is not that useful if you bring the file into PhotoShop where it immediately gets compressed to 8 bit channels. However, if the file was intended to go to an output that would take advantage of this extra bit depth, such as a film recorder, then this would probably make a good bit of difference.

I have not tried this myself. From most articles I read it still pays to capture the original file with greater bit depth even if it will be compressed in PhotoShop. The reason lies in how PhotoShop compresses the file, Bottom line; if Photoshop compresses the file from a higher bit depth file it will more accurately place the colors where they should be in the 16 bit depth file Vs. the file that was scanned at 8 bit depth from the start. Once again, if one thinks this is an issue when buying a scanner, try both and compare the outputs of the prints.

Work Flow :

Drum scanners are designed for high volume. So the combination of software, drum mounting stations and extra drums is designed to increase production dramatically. Most drum scanner software is designed to coordinate several tasks at once. For example, I can be doing a final 500 MB scan on one file while setting exposure values and saturation levels on another file. When I am done, I simply put this file in the queue for final scanning, it gets in line and waits its turn.When I am done, and waiting for a scans to finish on one drum, I can prepare my film mounting on a spare drum. This is usually performed on a drum mounting station. It's a custom-made device that holds the drums so that one can easily mount the film and acetate.

When the drum in the scanner is finished, you simply remove the drum and install the next drum. So all aspects of work flow is easily accommodated by the workstation, extra drums and software. Even though a 500 MB scan may take 35 minutes, it does not tie-up the scanner, since you can be doing so many other tasks that need to be completed before putting your next drum in the scanner. There is no waiting around for the scanner to finish.

The Drawbacks:

Price! A new drum scanner costs on the low end, $16,000 (4000 dpi) and on the high end (11,000 dpi) about $65,000. This usually does not include the drums, ($1500 - $2500 each), drum mounting stations ($1500 - $3000), or software ($1500 - $4000). So when you add it all up, it gets expensive Vs. lower-end flat bed scanners.

The good news is, a good few year old used unit can be purchased very inexpensively, and these machines are tanks, and are fairly reliable. A used scanner with warranty and support can be purchased for about 40% - 60% of the new values. So if you need drum scans, and have a lot of film to scan, owning a drum scanner can pay for itself very quickly.

Labs seem to charge very high prices for drum scanning. For example, 4x5" wet-mount scans at about 300MB cost between $70 and $130 each depending on the lab, their equipment and the expertise of the operators. Do the math and figure when your payback would be. For me, it was less than 2 years.

Size:

Drum scanners are large beasts. Mine takes up about a 2 ft x 4 ft area, plus the drum mounting station has about a 4 sq ft footprint. So you'd better have room to do all this. You also need a very strong table or support system as the scanners weigh in at 150 lbs, some over 200 lbs. And they operate at high speeds, like 1600 RPM, so vibration can disturb anything in the vicinity of the scanner. Here is a look at the scanner I own, the Howtek Hi Resolve 8000.

Speed:

Drum scanning takes a long time. Each step seems to add up; cleaning and examining the film, cleaning the drum, wet mounting the film to the drum, previewing the scans, touching up the scans, and then performing the final scan. It is time-consuming, but like everything else, you get out what you put in. Never underestimate how much time it takes to wet-mount film to a drum. It is a very tedious process getting the film straight and the acetate cover fully sealed to the drum to prevent fluid from spitting out when the drum is in the scanner and moving at speeds of 1600 RPM. Also, sometimes the speed of the drum will move air bubbles into the film area, in which case you need to re-mount and start over!

Mess:

Although with the new mounting fluids and cleaners the process is much improved over the older methods and products, you'll still have chemicals all over, drum cleaner, mounting fluid, film cleaner, scratch remover, etc. So your hands are wet, the chemicals smell a bit, they drip all over... it's just a bit messy compared to placing a chrome on a flat-bed. But as you can see from the wet mount-Vs. dry-mount link above, it sure does make a difference.

Support:

Drum scanners are not mass-produced items. Therefore the software and the support systems are not like calling an 800 number with mass produced flatbeds. Tech-support sometimes tries to figure out problems as they go along. Hopefully the scanner does not need to be sent back, since the freight is outrageous on these beasts. Most weight between 150 ø 200 lbs. Repairs are usually performed on site. I would not recommend buying a used drum scanner without prior knowledge of where support will come from. Unless you are already a knowledgeable scanner operator, you will need support, and possibly training.

Image size:

Most all drum scanners will only scan film up to about 8x10". There is a few drum scanners, like the Howtek Grand, that will scan up to 11 x 24", but these units are not sold often. The point is that many flatbeds have much larger scanning areas, which is necessary if one is scanning either 11x14" film or large reflective prints.

Final Thoughts:

Drum scanners are a major commitment to your art. They are serious machines that have steep learning curves. Most makers offer classes for $2 ø $3k just to learn how to use and perfect your scans. The advantages are many as mentioned above. However the drawbacks are also many. Each person must evaluate for themselves what would be best for their requirements.

I personally am very happy with my Howtek Hi Resolve 8000 scanner. It enables full control of my art right from the film to the final print. This is very important to me. In addition the cost of scanning at labs would have been exorbitant for me. There is unfortunately no easy way of comparing scanners short of doing tests yourself. Although this is cumbersome, itÕs sure worth the effort before making such a large investment in a machine you will probably own for many years.

Even though I own a drum scanner I would clearly like to share the following story, showing how good low-end flatbeds can be. Before buying this scanner, I had a dealer send me prints made on an Epson printer from the same transparency, one was scanned with a $2,500 Agfa DuoScan, one from an Imacon FlexTight $14,000 CCD scanner, and the last was made by an ICG drum scanner, one of the most expensive made at $65,000.

The chrome that was scanned was of good quality and did not have a very large exposure latitude, probably 2.5 stops. The prints were only on 8x10" paper and since the chrome was on 6x7cm all the scanners could easily handle the dpi required with no interpolation at approximately 1500 dpi.

So what was the results? I have to admit, I was quite shocked. When looking at all three prints I could see slight differences in color gamut, but not sharpness. I concluded that none of the prints looked better than the others and any of these color differences, which were slight, could have been easily been corrected in PhotoShop. OK, I had to place my bets on which was which, so I placed them in 1,2,3 order with the best being in first place. When I turned them over and looked at their ID, the order I placed them in was, Imacon, Agfa, ICG. Go figure, right? But when associates were asked the same question, they picked different orders, so this is how I concluded that none of them looked better than the others, just a bit different.

But keep in mind, this was an ideal arrangement where the transparency fit perfectly within the operating capabilities of all the scanners. But it sure goes to show you, that unless you get a magnifying glass out on the final print, you would be hard pressed to tell the difference between a $2,500 scanner and a $65,000 scanner if the item scanned is of good quality and the requirements are within the scanners capabilities.

What seems to be a good compromise for most people is as follows. But a low-end flatbed that fully meets the requirements of 70-80% of your scanning work. This will enable you to do a lot of your own work while saving money and controlling the entire process of scanning and printing. Then for the remainder of the work that requires more scanning horsepower to meet your requirements, outsource for drum scans for those special images. This way you will be maximizing your scanning dollars and saving yourself the hardship of drum scanning when it is not required for a majority of your work. There are also some shops that will allow people to rent their drum scanner for the day. Once you learn to use it, this can be another opportunity to reduce your costs on drum scans. Prices that I have heard range from $500 - $1,000 per day. Sounds high, but if you do 30 4x5" scans in one day, it would have cost you about $3,000 to have the lab to do the scans. Substantial savings indeed. Of course with MF or 35mm, you can scan many more than 30 per day.

I hope this review gives new-comers to high-end scanning a better insight into how best to approach their scanning needs. Best of luck!.