Canon PowerShot S20Canon packs 3 megapixels and a 2x optical zoom into their "smallest digicam" body!<<Video, Power, Software :(Previous) | (Next): Reference: Datasheet>> Page 12:Test Results & ConclusionReview First Posted: 4/4/2000 |
Test Results
In keeping with our standard policy, our comments here are rather condensed, summarizing our key findings: For a full commentary on each of the test images, see the Powershot S20's "pictures" page.
As with all Imaging Resource camera tests, we encourage you to let your own eyes be the judge of how well the devices performed: Explore the images on the pictures page, to see how well the S20 performed, and how its images compare to other cameras you may be considering buying.
Besides its small size and rugged body, the thing that most impressed us about the Powershot S20 was its exceptional resolution: We were expecting a good performance, due to the excellent detail it showed in some of our "natural" test targets, and in the very delicate in-camera sharpening it applied. We were frankly surprised though, when we saw just how well it performed in the laboratory resolution test. We were impressed with the resolution of some of the other 3 megapixel cameras we tested prior to the S20, most notably the Nikon Coolpix 990, but the S20 clearly has even the Coolpix beat in the resolution department. The S20's resolution appears to exceed what should be possible, based solely on its pixel count, a fact we attribute to its excellent suppression of artifacts. We "called" the S20's resolution as 900 lines per picture height in the horizontal direction, and 850-900 in the vertical, with detail visible in both directions as far out as 1000 lines. The lens also shows virtually no falloff of sharpness in the corners of the image, something we've become accustomed to seeing to one degree or another in most digicam images. As is commonly the case, sharpness at telephoto was slightly less than at wide angle, but the falloff really wasn't terribly significant. Really an exceptional performance!
Beyond the excellent resolution, detail, and sharpness, the S20's pictures showed pleasing color and saturation (neither over- nor under-saturated). It handled the difficult blues in our outdoor portrait test quite well, and generally had accurate color overall. The only fault we found in the color rendition was a tendency for strong highlights to go slightly magenta, the green channel dropping by about 2% relative to the red and blue. One reader had commented on this tendency in a unit he purchased, but we didn't find the amount of magenta in the highlights from our test unit objectionable. (Check the test images yourself, YMMV - Your Mileage May Vary.)
A further note to the above, added at the last minute: While we saw only the barest hints of it, some S20 owners have reported a tendency to shift bright blue colors markedly toward purple. We saw just the slightest tendency toward purple in the sky of our own outdoor shots, but feel we should also refer readers to this page, which shows several samples of images with rather purplish skies. That said, this is an absolutely tailor-made application for our favorite image-adjusting program PhotoGenetics: It's "IsoColor Evolution" function can develop a standardized correction for color problems of this sort, that you can then batch-apply to all your images. Although we didn't encounter the purple/blue problem to any significant extent in our own testing, we highly recommend the $45 PhotoGenetics program ($30 for the program, $15 for the IsoColor plug-in) to prospective S20 owners!
We would have liked to see more exposure control (such as aperture-priority and shutter-priority exposure modes, preferably even full manual), but that may not be as big an issue for a camera such as the S20, obviously aimed at the bring-it-anywhere recreational shooter rather than the technically-oriented enthusiast. (It does provide "action" and "slow shutter" modes that correspond to wide aperture/fast shutter/shallow depth of field and small aperture/slow shutter/greater depth of field respectively. This will cover many situations that would normally lead one to use either aperture- or shutter-priority metering.) Automatic exposure was quite accurate, with the default exposure being closer to correct on the outdoor/bright sun shots than most cameras we've tested.
One area we'd really like to see improved in the S20 is low-light shooting: It's adequate down to light levels you'd typically encounter at night under bright streetlights (1 footcandle), but we think at least another f-stop of speed would be helpful. (It's possible that production models may do better in this respect than the unit we tested, which had a maximum of 1 second exposure time in normal operating modes. The manual claims 2 second exposures for Night Mode, which would yield the extra factor of two in low-light we were looking for.) Three big positives about the S20's performance under dim lighting: 1) It has an autofocus-assist light, so it can focus in total darkness. 2) It isn't subject to the extreme color shifts at very low light levels we've seen in other cameras. 3) At moderate light levels (residential interiors), its incandescent white balance is a good bit better than most, producing well-balanced images with accurate color.
Another area with at least some room for improvement is the S20's optical viewfinder, as the current design only shows 76% of the final image area. Fortunately, the LCD viewfinder gives about 95% coverage, so you can look to it for critical framing.
The S20 performed well in Macro mode, with a minimum coverage area of 2.86 x 2.14 inches (72.63 x 54.47 mm). This is about average among digicams we've tested.
As a bottom line to our tests, the S20 delivered exceptional resolution and sharpness across the full frame (it has a great lens), with very good color and tonal rendition, in an exceptionally compact package.
Conclusion
With the S20, Canon kept the sleek, sophisticated, compact styling of the S10 and added a 3.3 megapixel CCD capable of delivering a much larger image resolution size (2048 x 1536). They also gave it an exceptionally sharp lens to match the sensor's resolution (producing the highest resolution we've measured on a digicam to date, as of late March, 2000). We found its color to be very good as well, both hue-accurate and properly saturated. (Neither over-bright nor dull.) While it lacks traditional aperture- and shutter-priority metering modes, much the same effects can be achieved through the "Fast Shutter" and "Slow Shutter" exposure modes. Overall, a great camera and a great extension of Canon's "Elph-like" digicam line. Highly recommended!
Follow Imaging Resource: