Digital Cameras - Canon PowerShot S500 Digital ELPH Test Images
|I've begun including links in our reviews to a Thumber-generated index page for the test shots. The Thumber data includes a host of information on the images, including shutter speed, ISOsetting, compression setting, etc. Rather than clutter the page below with *all*that detail, we're posting the Thumber index so only those interested inthe information need wade through it!|
NOTE: For those of you who've already read my review of Canon's PowerShot S410, you can save yourself some reading here. The results are very between the two cameras, so many of my remarks here are almost word for word the same as those for the S410. Overall though, the S500 has:
The extreme tonal range of this image makes it a tough shot for many digicams, which is precisely why I set it up this way, and why I shoot it with no fill flash or reflector to open the shadows. The object is to hold both highlight and shadow detail without producing a "flat" picture with muddy colors, and the PowerShot S500 Digital ELPH produced good color, but somewhat high contrast.
The shot at right was taken with a +0.3 EV exposure compensation adjustment, producing reasonably good midtones but dark shadows and lost detail in the strong highlights. (To my eye, this shot is marginally too dark, but felt that an exposure compensation of +0.7 EV resulted in too much lost highlight detail.) I felt that the Daylight white balance setting produced the best color balance here, although the Auto setting was fairly close. The Manual white balance setting seemed a little too warm.
Marti's skin tone looks very good, just slightly pink in some areas, but within acceptable limits and generally pleasing to the eye. The always-difficult blue flowers are just about perfect, a tough job for most digicams. (This is a difficult blue for many digicams to get right, but the S500 does an excellent job.) The strong reds, greens, and yellows also look good, with appropriate saturation despite the harsh lighting. Resolution is excellent, and details are crisp and well-defined, although it looks like the S500's anti-noise processing flattens out some of the subtle detail in Marti's hair. Shadow detail also looks good, with moderately low noise, although as noted, subtle detail suffers due to anti-noise processing. Overall, an excellent performance though.
To view the entire exposure series from zero to +1.0 EV, see files S50OUTMP0.HTM
through S50OUTMP3.HTM on the thumbnail index page.
Excellent resolution and detail, though high contrast once again.
Color and exposure are similar to the wider shot above, and the S500's 3x optical zoom lens helps prevent distortion of Marti's features. (A zoom lens is important for close-up portraits like this, to avoid the "chipmunk" distortion that a wide-angle lens causes.) The shot at right was also taken with a +0.3 EV exposure compensation adjustment, which again resulted in some blown highlights, but moderate midtones. The S500 again responded to the deliberately harsh lighting of the shot with high contrast, as in the wider shot above. Resolution and detail are much stronger here, with great definition in Marti's face, as well as in her hair. Skin tones are again good, just slightly pinkish in some areas, but appealing overall.
To view the entire exposure series from -0.3 to +0.7 EV, see files S50FACM1.HTM
through S50FACP2.HTM on the thumbnail index page.
Indoor Portrait, Flash:
Good intensity and coverage with the built-in flash, even at its default exposure setting, with good color as well.
The S500's built-in flash illuminated the subject very well, with good color, but some color cast from the fairly bright incandescent room lighting. The shot at right has a +1.3 EV exposure compensation adjustment (slightly more than usual for this shot), as the default exposure setting was rather dim. The overall color balance is warm from the background incandescent lighting, but still looks pretty good. Skin tones are reddish in places, but the blue flowers are surprisingly good. I also shot with the camera's Slow-Sync flash mode, which required only a +1.0 EV exposure compensation boost. The longer exposure time allows more ambient light into the image, which results in a stronger yellow-orange cast from the household incandescent lighting. Still, overall color is good, and the exposure is slightly more even than the normal flash shot.
To view the entire exposure series from zero to +1.7 EV in the normal flash mode, see files S50INFP01.HTM through S50INFP5.HTM on the thumbnail index page.
To see the same exposure series in the Slow-Sync mode, see files S50INFSP0.HTM
through S50INFSP5.HTM on the thumbnail index page.
Indoor Portrait, No Flash:
Good color with the Incandescent white balance option. Good exposure as well.
This shot is always a very tough test of a camera's white balance capability, given the strong, yellowish color cast of the household incandescent bulbs used for the lighting. The S500's Auto white balance had a lot of trouble here, producing a strong warm cast. The Manual setting produced nearly accurate results, though slightly yellow, while the Incandescent setting produced the best results overall, doing a truly excellent job with this difficult light source. Though just a tad reddish, the Incandescent image has the most accurate white value on Marti's shirt, and color is very good throughout the rest of the frame, even in the difficult blue flowers of the bouquet. The shots at right have a +1.0 EV exposure compensation adjustment, which is about average for this shot.
To view the entire exposure series from zero to +1.3 EV, see files S50INTP0.HTM
through S50INTP4.HTM on the thumbnail index page.
Great resolution, detail, and color.
The S500's Manual white balance setting produced
the best overall color here, with the most accurate white value on the
house trim. That said, the Auto and Daylight
settings both produced good color as well, just slightly warm. Resolution
is very high, with a lot of fine detail visible in the tree limbs and
front shrubbery. (The S500's five-megapixel CCD stretches the limits of
this poster as a test target. Even though the poster was made from a 500MB
scan of a 4x5 negative shot with a tack-sharp lens, the S500 extracts
nearly all the detail that's to be found here.) Details are also sharp
throughout most of the frame, but there's quite a bit of softness in the
corners on the left side.
High resolution, with a lot of fine detail visible. Good dynamic range, but some unfortunate distortion in the corners.
This image is shot at infinity to test far-field lens performance. NOTE that this image cannot be directly compared to the other "house" shot, which is a poster, shot in the studio. The rendering of detail in the poster will be very different than in this shot, and color values (and even the presence or absence of leaves on the trees!) will vary in this subject as the seasons progress. In general though, you can evaluate detail in the bricks, shingles and window detail, and in the tree branches against the sky. Compression artifacts are most likely to show in the trim along the edge of the roof, in the bricks, or in the relatively "flat" areas in the windows.
This is my ultimate "resolution shot," given the infinite range of detail in a natural scene like this, and the S500 does an excellent job with it. Detail is very strong in the tree limbs over the roof, as well as in the fine foliage in front of the house, with strong definition and clarity in the leaf patterns and tree bark. In-camera sharpening does a good job here, with crisp details throughout most of the frame, without visible "halos." The camera picks up moderate detail in the bright white paint surrounding the bay window, and detail is also strong in the shadow area above the front door. Exposure is a little bright, but overall color is good.
The biggest problem with this shot is that the S500's lens shows a lot of "coma" (blurring in the corners), and a fair amount of chromatic aberration there too. While the S500's lens is quite sharp, it does appear to lose sharpness in the corners of the frame.
The table below shows a standard resolution and quality series, followed by ISO and effects series.
Lens Zoom Range
A typical 3x zoom range.
I routinely shoot this series of images to show the field of view for each camera, with the lens at full wide angle, at maximum telephoto (3x, in this case), and at full telephoto with the digital zoom enabled. The S500's lens is equivalent to a 36-108mm zoom on a 35mm camera. That corresponds to a moderate wide angle to a moderate telephoto. Following are the results at each zoom setting.
Slight color casts with each white balance setting, but good results overall.
This shot is often a tough test for digicams, as the abundance of blue
in the composition frequently tricks white balance systems into producing
a warm color balance. Both the S500's Auto
and Daylight settings produced warm images,
while the Manual setting resulted in a cooler
image. Although it was a little too cool for my tastes, I preferred the
Manual white balance version to the overly-warm cast of the Auto and Daylight
shots. The blue robe looks about right, without any strong purple tints
in the deep shadows. Resolution is very high, with excellent detail in
the embroidery of the blue robe, as well as in the beaded necklaces and
flower garland. (The original data file for this poster was only 20MB
though, so cameras like the S500 are definitely capable of showing more
detail than the poster has in it.)
A very good performance, a very small macro area with good detail.
The S500 did a good job in the macro category, capturing a minimum area
of only 2.18 x 1.63 inches (55 x 41 millimeters). Resolution is very high,
and detail is strong in the dollar bill, coins, and brooch. Details are
softer in the coins and brooch, due the shallow depth of field caused
by the short shooting distance. There's also some softness in all four
corners of the frame, but this is fairly typical for digicam macro shots.
The S500's flash throttles down surprisingly
well for the macro area, but its position on the camera results in a dark
shadow in the lower right corner. - Plan on using external lighting for
the closest macro shots with the S500.
"Davebox" Test Target
Great color, good exposure.
The S500's Auto and Manual
settings both produced good color here, though I chose the Manual setting
for the main shot. (The Daylight setting was
too warm.) Though just slightly bright, exposure looks pretty good and
the S500 distinguishes the subtle tonal variations of the Q60 target well.
The large color blocks are accurate and well-saturated, although the additive
primaries (red, green, and blue) seem just slightly oversaturated Detail
is good in the shadow area of the charcoal briquettes, with moderate noise.
Overall, the biggest defect I see here is that there's a fair bit of lens
flare, visible as slight, glowing "halos" wherever there's a
bright white or colored area next to a darker one.
Excellent low-light performance, with great color balance and low noise.
The S500 did an excellent job here, and produced clear, bright, usable images down to the 1/16 foot-candle (0.67 lux) limit of my test at all four ISO settings. Color was good throughout the series, even at the darkest light levels. Given the S500's slightly higher-than-average noise under daylight conditions, I found the noise here surprisingly low in most cases, and even at ISO 400 was lower than I had anticipated. The S500 is also helped in its low light shooting by a bright autofocus assist illuminator, that lets it focus even in complete darkness. (At least on nearby subjects.) The table below shows the best exposure I was able to obtain for each of a range of illumination levels. Images in this table (like all sample photos) are untouched, exactly as they came from the camera.
(Note: If you'd like to use a light meter to check light levels for subjects you might be interested in shooting, a light level of 1 foot-candle corresponds to a normal exposure of 2 seconds at F/2.8 and ISO 100.)
Flash Range Test
Very good flash range, but perhaps a little "cheating" on the ISO? In any case, no significant falloff at the 14 foot limit of our test.
In my testing, the S500's flash illuminated the test target all the way out to 14 feet, without any significant decrease in image brightness. Looking closely at the images though, it seems that the S500 may be "cheating" a little, by secretly boosting the ISO to achieve the longer flash range. This tactic has actually become quite common in digicams, and it makes sense in most situations. I do wish though, that the manufacturers were a little more up-front about it. I'd like to see the cameras warn the user when the ISO was being boosted, and possibly provide an option to disable the boost, via a menu selection. Below is the flash range series, with distances from eight to 14 feet from the target.
High resolution, 1,200-1,250 lines of "strong detail." Average barrel distortion, though very low pincushion.
The S500 performed pretty well on the "laboratory" resolution test chart for its five-megapixel class. It started showing artifacts in the test patterns at resolutions as low as 800 lines per picture height, in both horizontal and vertical directions. I found "strong detail" out to 1,200-1,250 lines. (Actually, resolution is a little hard to call on the S500, as there's what appears to be meaningful detail visible well beyond the 1,250 line point, but there's also very strong aliasing. Some reviewers might be inclined to go as far as to say that there's 1,400 lines of resolution here, but my conservative nature says to call it quits when the aliasing gets as strong as the primary detail.) "Extinction" of the target patterns didn't occur until about 1,650 lines.
Geometric distortion on the S500 is about average at the wide-angle end, where I measured approximately 0.8 percent barrel distortion. The telephoto end fared much better, as I found only a half a pixel of pincushion distortion there. The S500's lens has some problems with coma and/or flare in the corners of the frame though, with a fair bit of softness evident, particularly along the left side. That said, chromatic aberration doesn't appear to be all that strong, as there's only fairly weak color visible on the fringes of the target elements. (This distortion is visible as a very slight colored fringe around the objects at the edges of the field of view on the resolution target.) Somewhat belying this though, is my experience on the outdoor, far-field test, in which I saw a fair bit of both softness and chromatic aberration in the corners of the frame.
Resolution Series, Wide Angle
Resolution Test, Telephoto
Viewfinder Accuracy/Flash Uniformity
Excellent accuracy from the LCD monitor, though the optical viewfinder is rather tight.
The S500's optical viewfinder is quite tight, showing only about 77 percent of the final frame area at wide angle, and about 78 percent at telephoto. The LCD monitor is much more accurate, with roughly 99 percent accuracy at both wide angle and telephoto. Given that I like LCD monitors to be as close to 100 percent accuracy as possible, the S500's LCD monitor is essentially perfect in this regard, but its optical viewfinder could definitely use some help. Flash distribution is fairly even at wide angle, with just a little falloff at the corners and edges of the frame. At telephoto, flash distribution is even more uniform.
S500 Test Images
S500 "Picky Details"
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