Canon Canonscan FS4000us scanner review

Bob Atkins Photography

Canon Canoscan FS4000US

What does it scan?

The FS4000US is designed to scan mounted 35mm slides (up to 4 at a time), 35mm negatives or unmounted 35mm slide strips (up to 6 frames) and APS film (up to 40 exposures). There is no provision for scanning uncut rolls of 35mm film and there is no slide feeder for unattended scanning of more than 4 slides at a time. If you want to scan more than 6 frames at once, APS is your best bet (actually your only option) as the FS4000US will automatically scan all 40 frames on a roll of APS film.

Scans can be made of positives (transparencies) or negatives in either in B&W at 8-bit or 14-bit depth or in color at 24-bit or 42-bit color depth.

This is a 35mm film scanner of course, so it does not scan prints or medium or large format slides and negatives.

How good is the Software (Canon FilmGet)

Some people make a big deal about scanner software. Can you correct colors easily? Can you correct contrast? Can you sharpen the image? Personally this doesn't bother me too much, since I expect to tweak every scan in a real image processing program like Photoshop, Picture Publisher (which the a program I tend to use most) or even Photoshop LE or Photoshop Elements which are bundled with most scanners (Photoshop LE 5.0 ships with the FS4000US). Just about any image processing program is better than just about any scanner software. The only advantage that using the scanner software might have is if the scanner software worked at greater bit depth than the final output image. For example if you told the scanner to output a 24-bit color image, but the scanner internally scanned at 42-bits and did all its corrections at 42-bits, then converted the result to 24-bits and output the file, then that would be better than editing the uncorrected 24-bit file. However this scanner doesn't do that. All the software corrections seem to be done at the 24-bit (8 bits per channel) level, whether the final output file is 42-bit or 24-bit. For the very best possible results, scan at 42-bit color depth, don't do any corrections with the supplied "FilmGet" software, output a 42-bit file and edit that in a 42-bit editing program. Then convert to a 24-bit file if that's the final form that you want.

The software installed easily. The scanner is plug and play of course, so you simply attach it to a USB port, power up the PC and the usual hardware install dialog pops up. You put the CD in your CD drive, tell the installer to look on the CD for the driver and away it goes. The first time I tried this, for some reason it installed the Spanish language version. Fine if you speak Spanish I guess, but I don't. A simple reinstall, making sure it got the file from the "English" subdirectory, fixed the problem.

The Filmget software which is supplied with the scanner is a TWAIN module, not a stand alone program. It is called from your image processing software and transfers the scanned image to the calling program. It has modest capabilities for correcting
  • Color
  • Histograms
  • Curves
  • Brightness
  • Rotation

As well as the usual controls over:

  • Scanning resolution
  • Cropping
  • Color Depth
  • Media type
  • Dust removal level
  • Focus (auto/manual)
  • Exposure (auto/manual)

In general the software is functional if not state of the art. Image update (showing the results of your changes) is somewhat slow and the degree of control is somewhat limited. That being said,  the software works, doesn't crash, is reasonably intuitive and is capable of transferring the image into an image processing program, which is more or less all I need it to do!

One slightly annoying feature is that the preview scan is done with the current dust removal setting and dust is removed in the preview image. One the one had this is useful to get a very general feel for how effective dust removal will be. On the other hand it slows the preview scan, and if you decide to change the dust removal setting, you have to do another preview scan since the old one (with whatever cropping and corrections you made to it) is erased. I suppose this is a feature, but it's one I could live without.

As mentioned earlier, one software "quirk" that others have noted is that it seems that the Canon Filmget software does all its image processing at the 8 bit level. This isn't a big deal with 8 bit images (i.e. 24 bit color images), but it is for 14 bit (42 bit color) images. If you process the 14 bit image at 8 bit precision and then save it at 14 bits, you lose information. If you want to scan 42 bit color images and need to process them to do color, density or histogram corrections, take the unprocessed output from the FS4000US and use an image processing program that can handle processing 16 bit (48 bit color) files.

Ed Hamrick's popular Vuescan program supports the FS4000US if you don't like the Canon software. It's much more flexible and offers many more options, though the price for this is a steeper learning curve and less intuitive interface. There's also a financial cost for the software too ($40), but you can get a trial version for free to see if you like it. Try it, see if you like it and register it if you do. Personally I still se the Canon software.

Neither Filmget nor Vuescan will allow you to scan 35mm true panoramic negatives (24mm x 60-72mm) in one scan, even though the filmholder windows are 72mm wide. Apparently this is due to a hardware, not software, limitations so don't expect any software to be able to do it. For panoramic negatives you have to scan in two parts then combine them with software.

How good is the hardware?

Pretty good! The FS4000US has the reputation for excellent optics and is regarded as one of the sharpest 4000dpi scanners around. I have no reason to question that based on my scans. So far mine (which is around one year old) has shown no mechanical problems, though it's only been subjected to light "amateur" use. The film and negative holders are good and the APS module worked perfectly the first time I plugged itin. The scanner makes all sorts of "whirring" noises and moves the film carrier back and forth several times before each scan, but that's the way it's designed I guess. Doesn't seem to result in any problems.

Above are a set of cropped scans of a high resolution "chrome on glass" copy of the 1951 USAF resolution test pattern. The leftmost image was scanned at 2000dpi and upsized by 200%. The middle image was scanned at 3000dpi and upsized by 133%. The rightmost image is a direct scan at 4000dpi, original size. It's quite clear that image quality improves as resolution increases. This isn't surprising of course, but it does show that the scanner isn't optically limited, i.e. the imaging system can take full advantage of the smaller step size used in high resolution scans. This image also answers the question "is it worth the extra expense of a 4000dpi scanner". The answer is, that, if you want to extract the maximum possible information from a slide, scanning at 4000 dpi is an advantage. As in all things it's really a user decision whether any added expense is worth any added performance. You don't need 4000dpi to scan for the web, but it's very useful if you're making large prints.


If you want real numbers, at 4000 dpi the last resolved pattern is group 6, set 2, which is 72 lp/mm. The horizontal component of group 6, set 3 is resolved, corresponding to 80 lp/mm. The theoretical maximum resolution at 4000 dpi, based on the Nyquist theorem which requires sampling at twice the signal frequency, should be 78 lp/mm. These numbers are approximate since we're looking at square waves not sine waves, but still it seems clear that the scanner is operating very close to the theoretical limit of resolution. It is also apparent that the autofocus funtion is working well, since any focus errors would result in lower resolution.

Real World Example

While the difference between the 2400dpi and 4000dpi scans isn't "night and day", the 4000 dpi scan clearly resolves more detail. The film grain is just starting to show up at 4000dpi, wheras at 2400dpi the grain isn't resolved. This image was shot on Sensia 100 film. With a higher resolution film like Velvia, the difference between scans at 2400dpi and 4000dpi might be expected to be greater since more detail would be recorded on the film.

Scan times

All these scan times were measured on a 550MHz AMD K6 PC (Windows 2000 Pro, 512MB RAM, 20GB free disk space) using the USB 1.1 interface. The times are from clicking on the "go" button to the end of the operation and so take into account time taken to move the slide carrier to the correct location (slide #3 in these tests) plus any other setup time as well as the actual scan and data processing and transfer time. Prior to full frame scan the scanning area was limited to the actual visible area of the mounted slide (the slide crops a little off the full frame image). The size of the full frame scans was approximately 5380 x 3550 pixels, making a 19MP image (57MB file at 24-bit color) and a 34.16mm x 22.54mm scanned area.

(all in color mode)

Dust Removal OFF Dust Removal ON Standard Dust Removal ON Strong
Calibration (done once at startup) 33s 33s 33s
Thumbnail scan (4 slides) 15s 15s 15s
Preview scan 38s 54s 54s
4000dpi 24 bit full frame scan of mounted slide (5380 x 3550 pixels) 4m 01s 6m 28s 6m 38s
4000dpi 42 bit full frame scan of mounted slide (5380 x 3550 pixels) 4m 13s 6m 45 6m 58s

It's interesting to note that scan times don't depend on whether the scan is done at 24 bit color depth or 42 bit color depth. This suggests that either scanning is always done at 42 bit, or that scan time is limited by the scanning itself, not by the data transfer rate. The extra time required for standard and strong dust removal is almost the same, suggesting the same algorithm is used in each case but with slightly different parameters. The scanner also has a SCSI port and connecting via SCSI may result in somewhat shorter scan times. I haven't tested this because the scanner is fast enough for my needs and I don't really want to mess with SCSI devices unless I have to! A faster processor would slightly reduce the overall times by speeding up the image processing functions (e.g. dust removal), but the difference would not likely be very significant since a faster processor won't speed up the scanner itself or the USB data transfer rate. This scanner isn't a speed king, but it's fast enough for me.

FARE (Film Automatic Retouching and Enhancement)

That's "dust and scratch removal" to most of us! Does it work...YES. It really does. Does it reduce sharpness...NO, or at least so little that it's hard to tell. Dust removal works by recording an infrared channel along with the usual red, green and blue channels, then using the information in the IR channel to tell the difference between dust and image. Scans take maybe 50% longer, but for a dusty slide it's well worth the extra time. The images bellow were cropped from full frame scans. Hardware techniques such as this are much more effective at dust removal than purely software techniques and cause much less loss of sharpness.

FARE does not work on conventional B&W negatives or on Kodachrome color slides. It does work on all C-41 and E-6 process films (color slides other than Kodachrome, color negatives and chromogenic B&W films). The reason it doesn't work is related to the infrared transmission characteristics of the film, which are different for C41/E6 and conventional B&W/Kodachrome.

Scanning or a Digital SLR?

I don't think there's much doubt that if your goal is digital images, you are better off shooting with a digital SLR than shooting film and scanning. It's cheaper, MUCH faster and a LOT less work. The drawback is that the digital SLR will cost you from $2000 to $8000 depending on the image quality you need. However, shooting with a digital SLR doesn't get any of your existing slides and negatives into digital form, and most photographers have LOTS of existing film based images. So even the digital SLR shooter probably still needs a film and slide scanner!

Digital SLRs are also a rapidly evolving technology, so today's new model is likely to be next month's "also ran" and next year's "obsolete model". Given that DSLRs are now fairly common, I think that we will see much slower evolution of film scanners. Higher resolution probably won't buy you much and the market for higher resolution scanners will be affected by the dropping prices on DSLRs. If I'm going to spend $2000+, I'm going to be looking at a DSLR, not a 6000dpi 35mm film scanner. So I think that now is a pretty good time to buy a scanner. Prices are reasonable, the technology isn't obsoleting new models every few months and even if higher resolution models appear, the marginal improvement in scan quality will probably be quite small. Though scanners with a larger dynamic range would certainly help with "difficult" (dense) slides, today's scanners are pretty good for 95% of properly exposed images. Canon claim a D-max of 3.4 in 24-bit mode and 4.2 in 42-bit mode for the FS4000US.


If you want a 4000dpi scanner with dust removal, this one is a bargain. If you want the ability to scan APS film it's even more of a bargain as it comes complete with an adapter for APS film! The scan quality is very high and the price is reasonable - in fact it's a real bargin since it has dropped from close to $1000 to around $550 over the last year. The price drop isn't because it's not a good scanner - it's a great scanner - it's just that demand for scanners has fallen since digital cameras became affordable, plus prices drop when any item of digital equipment has been around for a year or two!

Canon FS4000 at Amazon - now only $549.95

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