Canon A630 Exposure
Saturation & Hue Accuracy
Slightly oversaturated color (especially reds and blues), very typical of consumer digital cameras. Generally good hue accuracy.
Most consumer digital cameras produce color that's more highly saturated (more intense) than found in the original subjects. This is simply because most people like their color a bit brighter than life. The Canon A630 follows this trend, but the result you see at right is tempered from what we used to call "Canon color." That was never an insult, by the way, just a tendency to oversaturate colors like red and blue in a way that made for a beautiful image with somewhat clipped colors on occasion. We're happy to see it dialed back a bit, and also glad that the images still look great. Oversaturation is a big problem with Caucasian skin tones, as it's very easy for these "memory colors" to be seen as too bright, too pink, too yellow, etc. The A630 did render skin tones a bit on the pink side in most cases, but the images are still appealing.
The other important part of color rendition is hue accuracy. Hue is
"what color" the color is. Here, the Canon A630 did quite well.
Like most digicams, it shifts cyan colors toward blue, to produce better-looking
sky colors, but the rest of the hues were quite accurate.
Exposure and White Balance
Indoors, incandescent lighting
Unusually close results between Auto and Incandescent white balance settings, with Auto only slightly warm, and Incandescent only slightly cool.
|Auto White Balance +1.0EV||Incandescent WB +1.0EV|
Color balance indoors under Auto was slightly warm, and Incandescent mode was just a bit cool; both were still pleasing. The Canon A630 required a +1.0 EV exposure compensation boost to get a good exposure. Overall color well-balanced and hue accurate. Our test lighting for this shot is a mixture of 60 and 100 watt household incandescent bulb, a pretty yellow light source, but a very common one in typical home settings here in the U.S. The A630 handled this very yellow light source quite well.
Good color balance, very bright colors. Better than average exposure accuracy.
|Auto White Balance, Auto Exposure||Auto White Balance, Auto Exposure|
Outdoor shots generally showed accurate exposure with less a tendency to blow out highlights than I'm used to seeing. Shadow detail also tended to hold up pretty well for a consumer digicam. Exposure accuracy overall was better than average, the camera requiring less exposure compensation than I'm accustomed to seeing with consumer digicams.
High resolution, 1,300 lines of strong detail.
|Strong detail to 1,300 lines horizontal||Strong detail to 1,300 lines vertical|
Our laboratory resolution chart revealed sharp, distinct line patterns down to about 1,300 lines per picture height, with extinction at around 1,400. (The camera did produce slight color artifacts at lower line frequencies though, visible in the full-sized res target shots.) Use these numbers to compare with other cameras of similar resolution, or use them to see just what higher resolution can mean in terms of potential detail. Our interpretation of this standard is somewhat conservative. We watch for artifacts and color fringing then move back to the nearest pure part of the scale. In our opinion, detail with artifacts shouldn't be considered detail. You may see other numbers quoted elsewhere, but across the site, our reviews judge this parameter by the same conservative standard.
Sharpness & Detail
Fairly sharp images, with some blurring of detail from noise suppression.
The Canon A630's images are reasonably sharp, without strong over-sharpening or significant edge enhancement on the camera's part. (Edge enhancement creates the illusion of sharpness by enhancing colors and tones right at the edge of a rapid transition in color or tone.)
Noise-suppression systems in digital cameras tend to flatten-out detail in areas of subtle contrast. The effects can often be seen in shots of human hair, where the individual strands are lost and an almost "watercolor" look appears. The crop at far right shows this, with darker areas of Marti's hair showing only limited detail, even though individual strands are quite visible against her cheek in the uncropped image. The level of detail loss shown here isn't all that obvious on prints 8x10 inches or smaller, though, and this is quite a tight crop. This is a very good performance.
ISO & Noise Performance
No noticeable noise at normal sensitivity settings, which naturally increases at 400 and 800.
|ISO 80||ISO 100||ISO 200|
|ISO 400||ISO 800|
The Canon A630's sensitivity ranges from ISO 80 to 800 equivalents. Up to ISO 200, the PowerShot produced very little noise, with only slightly blurred detail in the dark areas. At ISO 400 and especially at 800, the noise level and the amount of blurring that results increases, but the images are still quite usable. The Canon A630's noise levels are lower than average for its class. At ISO 800, skin tones tend to purple a bit, but not nearly as bad as we've seen on other brands and models of camera.
Extremes: Sunlit and low light tests
High resolution with good overall detail, though high contrast and limited shadow detail. Pretty good low-light performance, capable of capturing bright images under average city street lighting and slightly darker conditions.
Because digital cameras are more like slide film than negative film (in that they tend to have a more limited tonal range), we test them in the harshest situations to see how they handle scenes with bright highlights and dark shadows, as well as what kind of sensitivity they have in low light. The shot above is designed to mimic the very harsh, contrasty effect of direct noonday sunlight, a very tough challenge for most digital cameras. (You can read details of this test here.)
The Canon A630 had a little trouble with the deliberately harsh lighting in the test above, producing very high contrast with deep shadows. We chose the +0.7EV adjusted image as the better choice, for the reasons stated above. Noise suppression is visible in both shadows and highlights as well, but plenty of detail is still evident. Exposure at least did not wash out the highlights when exposure compensation was set to zero adjustment. (In "real life" though, be sure to use fill flash in situations like the one shown above; it's better to shoot in the shade when possible.)
The Canon PowerShot A630 did very well in our low light tests, producing bright images at the lowest light levels at ISO 200 and above. At ISO 80 and 100, images were bright down to the 1/8 foot-candle level, about 1/8 as bright as average city street lighting at night. The one limitation though, is that you have to resort to Shutter Priority or Manual exposure mode to get exposure times longer than 1 second. As seen by the type in even the darkest images, the auto focus system worked well, relying on its AF assist lamp to find focus at the very darkest levels, but was also able to focus down at a bit less than 1/4 foot-candle without resorting to the AF assist. Given that typical city street-lighting at night is about one foot-candle (the brightest level shown in the test above), the Canon A630 should have no trouble handling the after-dark photography needs of most consumers.
NOTE: This low light test is conducted with a stationary subject, and the camera mounted on a sturdy tripod. Most digital cameras will fail miserably when faced with a moving subject in dim lighting. (For example, a child's ballet recital or a holiday pageant in a gymnasium.) For such applications, you may have better luck with a digital SLR camera, but even there, you'll likely need to set the focus manually. For information and reviews on digital SLRs, refer to our SLR review index page.
Coverage and Range
The A630's small flash has a limited range, produces a slight blue cast in combination with typical incandescent room lighting. Our standard shots required more exposure compensation than average.
|35mm equivalent||140mm equivalent||Normal Flash +1.0 EV|
Flash coverage was rather uneven at wide angle but very good at telephoto. In the Indoor test, the flash on the Canon A630 underexposed our subject at its default setting, requiring a +1.0 EV exposure compensation adjustment to get reasonably bright results.
Even at 16 feet, our most distant test range, the flash did illuminate the DaveBox target adequately. This agrees with camera's own spec of 14 feet for flash range, on the long side for a compact camera model.
|Manufacturer-Specified Flash Range|
Our standard test method for flash range uses a fixed setting of ISO 100, to provide a fair basis of comparison between cameras. We now also capture two shots using the manufacturer-specified camera settings, at the range the company claims for the camera, to assess the validity of the specific claims. In the shots above, the A630 seems to perform exactly as Canon says it will, producing good exposures at the rated distances with its ISO set to Auto. While the range is rather limited, the good news here is that the camera doesn't seem to be significantly boosting its ISO. This would produce greater flash range, but at the cost of higher image noise, and the noise levels from the Canon A630 seem quite acceptable.
Excellent print quality, great color, very usable 16x20 inch prints! ISO 800 images are quite usable at 8x10, excellent at 5x7 and smaller.
Testing hundreds of digital cameras, we've found that you can only tell just so much about a camera's image quality by viewing its images on-screen. Ultimately, there's no substitute for printing a lot of images and examining them closely. For this reason, we now routinely print sample images from the cameras we test on our Canon i9900 studio printer, and on the Canon iP5200 here in the office. (See the Canon i9900 review for details on that model.)
The Canon A630 made surprisingly good 16x20 inch prints at ISO 80 and 100. That's a big print. ISO 200 prints were better at 13x19 and smaller, and ISO 400 prints were still quite good at 11x14. Though some might accept ISO 800 prints at 11x14, we think 8x10 is a little better, though the color is a little more subdued. Drop the size to 5x7 and you really don't even notice that it's shot at ISO 800, except for the slightly darker colors. Quite an impressive performance from the Canon A630, almost identical to the 10 megapixel A640.