HP PhotoSmart S20 Scanner Test Images
|A word about our scanner testing philosophy: Some publications
have taken the position of scanning everything using the scanner's
default settings, believing this to be most fair, neutral methodology.
The problem with this approach is it may show unacceptable results
for an otherwise perfectly usable scanner. (Most users are willing
to engage in some tweaking of the scanning parameters to get
the best result.) For our part, we believe the most accurate
representation of real-world performance is to allow for a reasonable
level of twiddling of the scan parameters. In the interest of
objectivity though, we also show scans performed with default
settings, to provide a completely neutral reference point.
Also note that all images here have been JPEG compressed for compatibility with 'web browsers. This will degrade image quality somewhat, but we used a very conservative compression setting ("9" in Photoshop for the images below) to minimize this.
II" image: (760k) The main
image here was scanned at 1200x800 pixels (maximum res is about
3600 x 2400), and no tonal adjustments were made. Normally,
we'd comment here about all the manual adjustments we made to
improve the scan, but in this case, we didn't feel any were needed!
Here's a sample with the sharpening set
to 60, (1100k) (beautiful!) up from
the default value of 15 used in the main
(NOTE that this is NOT the identical "Musicians" image as used in our digital cameras test! It's very similar, but the models are different, and the digital-camera version is a couple of reproduction generations removed from this particular version.)
"Musicians II" detail clip: (756k) The PhotoSmart's 2400 dpi is solidly in the mainstream of high-resolution film scanners. This clip was taken from a maximum-resolution scan of the Musicians II image. Note how easily you can see individual strands of the model's hair, and how completely free from pixelation the overall image is! We mentioned earlier how well and subtly the PhotoSmart's sharpening algorithm worked: The table below has links to samples scanned with sharpening settings of 30, 60, and 100 (the default value is 15). The setting of 100 is really too much, as it tends to emphasize noise & grain, but overall the sharpening is really beautiful. (Well, maybe we wax a little euphoric, but it's really, really good!) Here's a composite (288K) of the small shots we referenced in the main review, showing the effects of Photoshop unsharp masking (top), default sharpening in the scanner (center), and scanner sharpening set to 60 (bottom).
|Kodak Royal Gold 25
"House" detail clip: (596k)
This is a detail clip from the same negative used to produce
the "house" poster for our digital camera tests. It
was shot on Kodak Royal Gold 25 film, which is extremely fine-grained,
but which has very different color characteristics from most
normal color negative films. The new PhotoSmart did a fairly
good job of handling this unusual film producing a default
scan (556k) that's somewhat light
and a little reddish, but overall surprisingly well-balanced
for this subject. This was one of the few images we had to tweak
manually to improve relative to the default settings: For our
main image (596k),
we stretched both the highlight and shadow portions of the tonal
range, and moved the color balance a bit more toward green and
away from magenta.
Print scan sample: We also ran a low-res scan of a mini-lab print (604k) made from this negative, showing the color balance there, which was more normal. (The strangeness of the film having been largely corrected for by the mini-lab photo printer.)
|"Train" Shot (Extreme shadow detail): (492k) This slide is a tremendously tough test of scanner performance in extreme shadow regions. The PhotoSmart S20 again did surprisingly well here. The default scan (680k) came out rather dark, as befits the subject. For our main image (492k), we boosted the overall brightness a fair bit, and the shadow values slightly. (We wanted to open up the shadows, but also wanted the shadows to run all the way to maximum black, to make best use of the tonal range.) The result is quite good, on a par with many more-expensive scanners we've tested. This shot (640k) shows the results of some additional tweaking in Photoshop, bringing out more detail in the shadows and adjusting the color balance at that end of the tone curve somewhat. Overall, performance on this difficult subject was very good, and noise was surprisingly low for such an inexpensive input device.
|Q60 Color Target: (136k) Kodak's "Q60" color target (formally adopted by the ISO as part of the IT8 color standard) is a good test of color accuracy and tonal rendition. Once again, we found no need to adjust the scanning options away from their default settings! Tonal range is excellent, with even step 22 of the grayscale showing some differentiation from step 21, although there's a fair bit of noise that far down, and the color balance shifts to the magenta. Notably though, step 20 of the scale is very neutral in color, and shows almost no noise at all. Color accuracy is excellent everywhere, with good saturation in the strong primaries, but delicate handling of the pastels as well.
|"Davebox" test target: (292k) As we've commented on in the past, color negative film is weird, but the S20 seems to handle most common types remarkably well. The main image (292k) here was shot on Kodak Gold 100, and once again, we felt no need to adjust the scanning parameters away from their default values. Print Scan sample: This image (320k) was scanned from a print made from the Kodak Gold 100 negative used above. It shows the lighter bands in the dark areas we noted in the main review. Our test of the previous PhotoSmart scanner using this subject showed light bands running across the image, caused by shadows of the transport rollers affecting the calibration process. We saw none of this behavior on our test unit of the S20, but have heard from at least one reader saying he saw the effect in his unit. For our part, it appears that this problem is cured
|WG-18 Resolution Target Horizontal Clip: (48k) The full WG-18 target is very large (see below), so we cropped-out these snippets to show the scanner resolution on this familiar target. The original shot here was taken on Kodak Tech Pan black & white negative film, probably the highest-resolution film currently made, shot with the very sharp Nikon 50mm f/1.4 lens. Still, it is definitely not to be considered a laboratory-grade standard. Nevertheless, this will give a fair indication of maximum performance with the upper end of consumer-grade film emulsions. The horizontally oriented target (vertical resolution) shows a visual resolution of about 1400-1600 line pairs/picture height, a very good performance, about the same as the earlier PhotoSmart.
|WG-18 Resolution Target Vertical Clip: (44k) Here's the corresponding vertically-oriented clip of the WG-18/Kodak Tech Pan target. Visual resolution is virtually identical to the horizontal clip, although with perhaps a shade less contrast at the highest line frequencies. Very impressive resolution performance!
Full-Size WG-18 Resolution Target: (1,292k!) For the real masochists, here's the full-size WG-18 target, scanned at the maximum resolution of 2400 dpi. A side note: We didn't explicitly set up a test for frame coverage by scanners, but our WG-18 shot goes right to the edges of the 35mm frame. This shot shows that the PhotoSmart S20 Scanner can scan all the way to (and even slightly beyond) the edges of the 35mm frame.
WARNING: This JPEG expands to a 7.7 megabyte file, which will may crash your browser if viewed directly! To view it, you must first download it directly to your hard drive (right-click in Windows, click & hold in Mac Netscape), then open it in an image-editing application. Here is the link to the RAW JPEG IMAGE (1,292k!) (No surrounding HTML file.)
|USAF 1951 Resolution Target: (340k) (Elderly technoids only ;-) Old-line lens and film testers will be well-familiar with the "USAF 1951" resolution test target. (1951 is the year it was created, giving you an idea of what we mean when we say "old-line".) This was scanned at the maximum 2400 dpi from a laboratory-grade target (chrome on glass slide) before being cropped down, and would normally give an excellent view of the scanner's ultimate capabilities. In this case though, the exterior-surface test pattern falls slightly outside the optimum focal range of the PhotoSmart's fixed-focus optics. The results are still impressive, with the last distinguishable feature being group 5, element 5 vertically, at 50.5 line cycles/mm (1290 line pairs/inch); and group 5, element 3 horizontally, at 40.3 line cycles/mm (1024 line pairs/inch). The short extent of the USAF pattern targets doesn't permit the sort of visual interpolation our eyes do naturally on the more extended WG-18 pattern. As a result, the USAF target should yield much more conservative resolution numbers.