The current generation of scanners is already very good as far as resolution and image quality are concerned. However, there are areas where future technical advances will hopefully make the user’s life easier. As there are often misleading ideas about the capabilities of the units, it is important to address a few points. I started this list in 2004 and was quite confident that we would see a new generation of high-quality scanners soon. Unfortunately, it is now 2009 and no major changes happened in the meantime! Anyway, I think it is important to point out the technical limitations of current scanning devices.
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At the time of writing (January 2009), it is not worth waiting for new generation scanners to hit the market. Scanner manufacturers are not funding serious development, and we do not expect to see any significant technological advances in the near future. In contrast, even Nikon – the only residual manufacturer for high-quality desktop scanners – has announced it will completely stop its scanner production soon.
For many scanners, the speed of the scanning still leaves room for improvement. The norm is several minutes per image, which obviously slows down work. Faster scanning would be preferable. Scanning times of around one minute per image with image corrections turned on would clearly make scanning more enjoyable. With the current state of scanner technology, one weekend will not be enough to scan an archive of a few hundred images. Several weeks would be more realistic.
The fastest desktop film scanner I know is the Nikon Super Coolscan 5000 ED. Hooked up to a powerful computer, it allows for speedy work. Scanning a slide with activated ICE takes around one minute, which is quite acceptable. However, GEM and ROC further increase this time. Other scanner models are substantially slower. Scanning times of up to nine minutes for one image with ICE correction surely will not allow you to work efficiently.
Once you have learned to appreciate the benefits of ICE, you will no longer want to do without it. Without much user interaction; slides will appear free of dust and scratches. Unfortunately, there is still no process supported by scanner manufacturers that also works for traditional black-and-white film. Especially with high-quality scanners, black-and-white negatives produce less than ideal results. The soft lens of a bad scanner makes some of the smaller blemishes disappear; yet, a good scanner scans not only the film but also every grain of dust on it and even the tiniest scratch with merciless precision.
Depending on the type of light source and the quality of the scanner lens, this effect will be more or less pronounced. You can remove the dust and scratches with software, but it is very tedious and cannot attain the results of ICE for color film. Scanhancer is a good tool to generally suppress dust and scratches. However, there is still no sound solution. Since all scanner manufacturers have frozen their development budgets, this problem will remain for the foreseeable future.
In my scans, the depth of field issue has often reared its ugly head. The color of the scan is fine, but the sharpness is often limited to certain areas of the image. This problem always happens with warped originals and can be reduced only with tensioning mounts. In such cases, one has to choose whether to focus on the image center or the edge. A certain loss of sharpness toward the corners of the image is a natural characteristic of any camera lens, so the film is already less sharp there. Unfortunately, the limited depth of field of the scanner lens further adds to the softness in the picture, and ultimately this leads to visibly blurry portions in the scanned image. This problem varies with different manufacturers. Nikon scanners are infamous for their shallow depth of field.
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Scan softness can have various causes, including the original itself. You can best check the sharpness of your original using a loupe and a light box. Scanners sometimes simply focus incorrectly, and warps and bends in the original are also often the cause of the problem.
Originals are not always sufficiently flat to be scanned equally sharp from center to edge. The images on the previous page demonstrate this nicely. At first, a curved slide was scanned. It was not possible to maintain even sharpness across the entire image; the eyes and the bell on the jester’s stomach cannot be sharp at the same time. Then the slide was remounted into a Wess slide mount with a tensioning feature, which pulls the film reasonably flat. With reasonably flat film, the sharpness extends across the entire area. In both cases, the focus point was the left eye of the jester. ICE was deliberately disabled, since it causes slight blurring.
Tensioning slide frames is too troublesome and expensive for a large number of slides. The Wess website has not been accessible for some time now, so the company may be out of business already, but you will still be able to find some of their frames at www.filmscanner.info. Furthermore, it is not common to frame negatives, although it is possible for the purpose of scanning. Keep in mind that once the negatives are cut, they are no longer accepted at photo lab chains.
Nikon has not found an ideal solution for curved filmstrips either. In my opinion, Nikon’s FH-3 filmstrip holder still has plenty of room for improvement. Wavy filmstrips become a little less wavy, but a proper flatness is not achieved. Unfortunately, I don’t know of any better film adapters from other makers. In the twenty-first century, it ought to be possible to build a film holder that can pull curved film flat.
Anyone who has used a film scanner before will understand why the issue of ergonomics is brought up here. Many models produce buzzing and chattering noises that can be unpleasantly loud. You have to be very indifferent to noise if you want to run a scanner in your living room and do other things at the same time. Flatbed scanners are better in that respect; their noise level is usually more agreeable.