Canon PowerShot G5The next generation of Canon's popular "G" model updates the line with a larger, 5.0-megapixel CCD.
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G5 Sample ImagesReview First Posted: 08/18/2003
Digital Cameras - Canon PowerShot G5 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, ISO setting, compression setting, etc. Rather than clutter the page below with *all* that detail, we're posting the Thumber index so only those interested in the information need wade through it!|
|Outdoor Portrait: |
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 G5 performed very well, particularly when I used its low contrast option.
The shot at right was taken with a +0.7 EV exposure compensation adjustment, and a Low contrast adjustment. Midtones are bright with good detail, though the highlights are slightly blown out. At the default contrast setting, highlights were much too bright, with even less visible detail. I chose the Daylight white balance as the most accurate overall color balance, though the Auto setting produced similar results (just slightly warmer). The Manual setting produced a stronger warm cast.
Marti's skin tones are a little orange here, with some stronger magenta tints in the lighter shadows, but the color is well within acceptable limits. The blue flowers in the bouquet are almost perfect. (This is a very difficult blue for many digicams to get right. The G5 pretty much nails their color.) The camera also did a good job with the strong red and green tones, and the bright yellow flower looks very good as well. Overall saturation is just a bit high, but again, well within what I'd consider an acceptable range. Resolution is excellent, with a lot of fine detail visible throughout the frame, even in the shadows. Details are also sharp, and image noise the shadows is quite low. A very nice job. Following is a contrast comparison and a saturation series.
To view the entire exposure series from zero to +1.3 EV, see files G5OUTDLCP0.HTM through G5OUTDLCP4.HTM on the thumbnail index page.
Excellent resolution and detail.
Overall results are similar to the wider shot above, in terms of color, and the G5's 4x zoom lens helps prevent distortion of Marti's features. Detail is much stronger in this shot, with excellent definition in Marti's face and hair. You can easily count the strands of her hair in some areas. The shot at right was taken with no exposure compensation adjustment, although some of the shadows on her face are a little deeper than I felt they were in the original scene. I didn't want to add any exposure compensation though, as the highlights were already blown out on the collar of her shirt, and the highlight on her nose was on the verge of losing detail. Detail is also very good in the shadows, with low noise.
To view the entire exposure series from -0.3 to +1.0 EV, see files G5FACM1.HTM through G5FACP3.HTM on the thumbnail index page.
Pretty good intensity and coverage with the built-in flash, but a strong color cast from the household lighting.
The G5's built-in flash illuminated the subject fairly well, though intensity was just a bit dim at the default exposure. I found the best results with a +0.3 EV exposure compensation adjustment, which left the highlight detail intact, but brightened the image sufficiently otherwise. The background incandescent lighting results in an orange cast overall, more than I'd really like to see on this shot. I also shot with the camera's Slow Sync flash mode, which combines the flash with a longer shutter time. The best image in that mode was obtained with a +1.7 EV exposure compensation adjustment, which is quite a bit more than average. Color balance was still quite orange from the incandescent lighting, but overall results are similar to the normal flash shot. (Here's a sample image at the default exposure.)
To view the entire exposure series in the normal flash mode from -0.3 to +1.7 EV, see files G5INAFM1.HTM through G5INAFP5.HTM on the thumbnail index page.
To view the exposure series in the Slow Sync flash mode from -0.3 to +2.0 EV, see files G5INAFSM1.HTM through G5INAFSP6.HTM on the thumbnail index page.
Excellent color with the Incandescent white balance option, but good results with Manual 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 G5's Incandescent white balance did an excellent job here, producing a very natural-looking image with just a hint of warmth to suggest the warm tones of the original lighting. The Manual option also produced nice overall color, albeit with a slightly greenish tint. The Auto setting had a lot of trouble here though, producing a strong orange cast. Marti's skin tone is slightly pinkish, and the blue flowers are just a little dark. Still, overall color is pretty good. The main shot has a +1.0 EV exposure compensation adjustment, about average for this shot among the digicams I've tested. Anything brighter increased the magenta cast and lost detail in the highlights.
Excellent resolution, detail, and color.
The G5's Daylight white balance setting produced great results here, with the most accurate white value on the house trim and best overall color. That said, the Auto and Manual settings produced good results as well, though the Auto setting was slightly reddish and the Manual setting slightly cool. Resolution is excellent, and the G5 captures nearly all the detail that's to be found here. The tree limbs above the roof show great detail, as does the shrubbery in front of the house and the house front. (Even though the poster was made from a 500MB scan of a 4x5 negative shot with a tack-sharp lens, the G5 extracts nearly all of the detail that's present.) Details are also sharp throughout the frame, though the top corners betray some softness. Overall, a great job.
Excellent resolution, detail, and color, although a little softness in the corners, and some flare in the tree branches against the sky. Excellent dynamic range, though.
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 G5 performs very well. Detail is strong in the central portion of the tree limbs over the roof, but strongest in the fine foliage in front of the house. Leaf patterns in the shrubbery are very well defined, as are the tiny details of the house front. Details are sharp throughout most of the frame, however, there's some softness in the upper corners of the image, which encroaches on the top center of the frame as well. I also noticed some flare from the lens, which appears as a purplish halo around areas of blue sky in the top of the frame, and a ghostly appearance in the pine branches against the sky. To its credit, the camera picks up good detail in the bright white paint surrounding the bay window, which is a trouble spot for many digicams. Detail is also strong in the shadow area above the front door, further evidence of the G5's excellent dynamic range. Overall color looks good, and exposure is about right. The table below shows a standard resolution and quality series, followed by ISO, sharpness, contrast, saturation, and effects series.
Lens Zoom Range
Excellent 4x 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 (4x, in this case), and at full telephoto with the digital zoom enabled. The G5's lens is equivalent to a 35-140mm zoom on a 35mm camera. That corresponds to an average wide angle to a fairly substantial telephoto. Following are the results at each zoom setting.
Pretty good color, although none of the white balance settings totally nailed it. Good good detail.
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. The G5's Manual white balance setting did the best job here, with good skin tones and overall color. The Daylight setting produced nearly accurate results, but with a very slight magenta cast. The Auto setting had a lot of trouble here, and produced a strong orange/red cast. Even with the (very) slight cool tone of the Manual white balance, the blue background has a few faint purplish tints that aren't in the original image. The blue robe is also slightly purplish, mainly in the shadow areas. Resolution is very high, with great detail in the embroidery of the blue robe. (The original data file for this poster was only 20MB, so cameras like the G5 are definitely capable of showing more detail than the poster has in it.)
A tiny macro area with great detail.
The G5 performed well in the macro category, capturing a minimum area of 2.74 x 2.05 inches (69 x 52 millimeters). Resolution is very high, with strong detail in the dollar bill, coins, and brooch. Corner softness is only slightly visible in the top corners. The G5's flash had trouble throttling down for the macro area, overexposing the top left corner of the frame, and the camera's lens cast a dark shadow in the bottom right corner. - Plan on using external illumination for close-in macro shots.
Good overall color and exposure, with low noise and a good dynamic range.
The G5's Auto white balance produced the best
color here, with the most accurate white value in the mini-resolution
target and large, white color block, despite a slight warm cast. The Daylight
setting was just a hint warmer, and the Manual
setting had a slight greenish tint. Exposure looks about right, and the
G5 has no trouble distinguishing the subtle tonal variations of the Q60
target. Colors are bright and vibrant in the large color blocks, though
the red and blue additive primary color blocks are slightly oversaturated.
The shadow area of the charcoal briquettes has strong detail, with low
noise, and the last steps of both gray scales are just barely distinguishable,
showing excellent shadow detail.
Image Noise, across the generations:
One thing that's happening, as manufacturers press on toward ever-higher pixel counts, is that CCD noise is gradually creeping upward as well. This is a largely unavoidable fact of life, because the factors that produce image noise increase as sensor pixels become physically smaller. Overall, we're clearly approaching the point at which picky users will need to choose between higher resolution and lower image noise. (Although the high end of the market seems to be more or less forcing users toward more pixels, regardless of how they feel about image noise.) While this is true overall, Canon appears to have done an excellent job of holding the line on noise, through improved electronics and image processing algorithms, somewhat compensating for the increase in baseline sensor noise. I put together the table below, comparing image noise in ISO 50 shots of the Davebox, shot with the original 3-megapixel G1, the 4-megapixel G2, and the 5-megapixel G5. (I didn't have a copy of the relevant test shot from the G3 captured at ISO 50 to measure it's noise with, so my comparison only involved the G1, G2, and G5.) What I found interesting here was how little the image noise increased in going from the 3-megapixel G1 to the 5-megapixel G5. Also interesting was the way in which the noise tradeoffs seemed to move around the color spectrum with changes in the camera model. (The G1 had particularly low noise in the yellow block, and was highest in the blues, while the G2 was lowest in the magenta block, highest in the cyan. The G5 seemed to generally track the G2's noise pattern.) This also shows why it's not sufficient to simply look at image noise in neutral gray shades, as the noise is often very color-dependent. The graph below shows how the three cameras' noise levels compare across the spectrum, with the numerical standard deviation (noise) numbers listed below the chart. You can see how little difference there is between the three cameras, and how the G5 actually slightly beats the lower-reolution G2 in many parts of the spectrum. Great job, Canon!
Excellent low-light performance with good color and exposure at all sensitivity settings.
The G5 features full manual exposure control and a maximum exposure time of 15 seconds, which provides great low-light shooting capabilities. The camera produced clear, bright, usable images down to the 1/16 foot-candle (0.67 lux) limit of my test, with good color at all four ISO settings. The camera also has a bright autofocus illuminator, so it had no trouble focusing, even in total darkness. Noise was low in most cases, and even at ISO 400 remained reasonable. The table below shows the best exposure we were able to obtain for each of a range of illumination levels. Images in this table (like all of our sample photos) are untouched, exactly as they came from the camera.
Flash Range Test
A powerful flash, only a little falloff at the 14 foot limit of our test.
In my testing, the G5's flash illuminated the test target all the way out to 14 feet, without any significant decrease in intensity. Like many current consumer digicams though, I suspect that the G5 is "cheating" slightly by boosting its ISO setting when the flash is active. My software for reading EXIF header information isn't able to extract ISO information from the G5's files, but the noise levels in flash images are noticeably higher than those lit by bright external light sources. Below is the flash range series, with distances from eight to 14 feet from the target.
Very high resolution, 1,250 lines of "strong detail." Average barrel distortion, higher than average pincushion though.
The G5 performed very well on the "laboratory" resolution test chart. It started showing artifacts in the test patterns at resolutions as low as 750 lines per picture height, in both horizontal and vertical directions. I found "strong detail" out to at least 1,250 lines. "Extinction" of the target patterns didn't occur until about 1,600 lines. The G5's performance though, shows the tradeoff manufacturers face between aliasing and resolution. In the G5, Canon seems to have cut their antialiasing filter to the bare minimum, while keeping their unsharp masking operator very tight. The result is excellent rendition of fine detail, and minimum perturbation to the raw image data, but at the cost of a greater tendency to alias (visible in the form of "jaggies" and varying widths of the fine target lines here) than some of the competition. (By contrast, Nikon tends to be much more conservative in their antialiasing, using a stronger AA filter (producing images that are softer, but with fewer artifacts), then trying to compensate by cranking up the in-camera sharpening. The result are images with slight "halos" around strong contrast edges and less fine detail, but virtually no aliasing visible. -- To see what I mean, compare the vertically oriented resolution wedges here with those from Nikon's Coolpix 5700 in the Comparometer. - You'll see more jagginess on the G5's images, but also a good bit crisper-looking image. I don't think there's a "right" or "wrong" here, they're just different choices in how to make the tradeoffs. Some photographers will prefer one, some will prefer the other...) -- To see what I mean, compare the vertically oriented resolution wedges here with those from Nikon's Coolpix 5700 in the Comparometer. - You'll see more jagginess on the G5's images, but also a good bit crisper-looking image. I don't think there's a "right" or "wrong" here, they're just different choices in how to make the tradeoffs. Some photographers will prefer one, some will prefer the other...)
Optical distortion on the G5 is slightly better than average at the wide-angle end, where I measured approximately 0.7 percent barrel distortion. The telephoto end fared much better, as I found only 0.3 percent pincushion distortion. Chromatic aberration is very low, showing only about two or three pixels of very faint coloration on either side of the target lines. (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.) The only other distortion I noticed was some flare in the patches of blue sky in the outdoor house shot, and some occasional softness in the corners of the frame.
Resolution Series, Wide Angle
Resolution Test, Telephoto
Viewfinder Accuracy/Flash Uniformity
An average optical viewfinder, but very accurate LCD monitor.
The G5's optical viewfinder is a little tight, showing approximately 86 percent frame accuracy at wide angle, and approximately 85 percent at telephoto. (This is quite typical of the optical viewfinders on digicams I test, but IMHO is too tight - I'd really like to see optical viewfinders on cameras more in the 95% range.) The LCD monitor proved much more accurate, showing roughly 100 percent accuracy at both zoom settings. Given that I like LCD monitors to be as close to 100 percent accuracy as possible, the G5's LCD monitor is essentially perfect in this regard. 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 more uniform.