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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Page 12:Test Results & ConclusionReview First Posted: 08/18/2003
In keeping with my standard test policy, the comments given here summarize only my key findings. For a full commentary on each of the test images, see the G5's "pictures" page.
As with all Imaging Resource product tests, I encourage you to let your own eyes be the judge of how well the camera performed. Explore the images on the pictures page, to see how G5's images compare to other cameras you may be considering.
- Color: The G5 produced excellent color throughout my testing.
Color saturation was typically just about right, and hue was nearly always
dead-on. The difficult blue flowers looked good in the Outdoor portrait, but
were slightly dark indoors, although this last is much to be expected, given
the very warm-toned lighting on that shot. Strong additive primaries such
as red and blue were often just slightly oversaturated, but not too badly.
Skin tones were typically slightly orange or slightly pink, but overall pleasing.
White balance was very good under virtually all light sources, even the very
difficult household incandescent lighting of my "indoor portrait"
test, although the G5's Auto white balance setting had trouble there, and
the indoor flash shot was quite orange from the room lighting. I noticed a
tendency for the Auto and Daylight settings to run slightly warm, and the
Manual setting to be a little cool and greenish, but the amount of deviation
was fairly small under natural light sources. Overall, a very good job.
- Exposure: The G5 did a great job with exposure in most
cases, and handled the test lighting well. As is typical, it underexposed
the very high-key outdoor portrait shot just a little, but not as much as
most cameras I test do. It did produce high contrast in response to that shots
deliberately harsh lighting, but the camera's contrast adjustment did a good
job of restoring detail to the shadows and highlights. Indoors, the camera
required an average amount of positive exposure compensation to achieve a
good exposure on my "Indoor Portrait test." On my "Davebox"
test, the G5 had no trouble distinguishing the subtle pastel tones of the
Q60 target, while still holding good detail in the deep shadows. Overall,
excellent exposure characteristics.
- Image Noise: This isn't one of my standard "Test results"
categories, but it's worth mentioning. I was surprised by how little image
noise crept up with increasing resolution, as we've gone from the original
3-megapixel G1 to the four-megapixel G2 and now to 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.) Here's a chart of my results, see the "Davebox" portion of
the pictures page for more discussion:
- Resolution/Sharpness: 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.
- See the resolution chart section of the Test Pictures
page for further details.
- Closeups: 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.
- Night Shots: 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.
- Viewfinder Accuracy: 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, but
really like to see manufacturers bring their optical viewfinders closer to
a full-frame view. (No special knock against Canon, this is unfortunately
standard across the industry.)
- Optical Distortion: 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.
- Battery Life: In a word, excellent. Like prior models in
Canon's G-series, the G5 has excellent battery life. Worst-case runtime is
162 minutes in capture mode with the LCD turned on, stretching to an exceptional
11 hours with the LCD off.
- Shutter Lag and Cycle Time: The G5's shutter lag is slightly on the slow side of average, with lag times of 1.17 seconds at telephoto and 1.04 seconds at wide angle. (Average is between 0.8 and 1.0 second.) This isn't terrible, but is probably the weakest point of the G5's design. I confess that I don't understand why digicam makers can't seem to lick the shutter lag problem. (Why don't they just add an IR-based AF system as are found in film-based point & shoots?) I'd have hoped that Canon could have done better than "average" in this critical area on their flagship prosumer model. Prefocus shutter lag is a blazing 0.095 seconds though. Cycle times are very good, right around 2 seconds for large/fine JPEG images, and the camera's buffer memory holds at least 4 shots before you'll have to wait for the memory card to catch up.
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Canon's "G" series of digicams have always been favorites of mine,
and I was especially thrilled with all the updated features found on the G3
model. When the G3 came out though, the question on everyone's lips was "Where's
the 5 megapixel model?" Well, here it is, and it's a dandy. All the features
and performance of the G3, but with an extra megapixel of resolution. - And
surprisingly good image noise for a five-megapixel sensor. With its 4x optical
zoom lens, 5 megapixel sensor, and myriad exposure controls, the G5 has enough
to suit experienced users and pros, while remaining approachable by novices
when used in full-auto mode or one of its "scene" options. It doesn't
take a crystal ball to predict big sales for Canon on this model. Highly recommended.
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