Canon PowerShot SD870 IS Exposure
Saturation & Hue Accuracy
Very good color, with good overall saturation. Some slight shifts in cyans and reds, and a small amount of oversaturation in strong reds and blues, but still very good results.
Saturation. The Canon PowerShot SD870 IS pushes the strong red and some blue tones just a bit, but overall results are very pleasing. 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.
Skin tones. The Canon SD870 IS again does a good job, and produces natural skin tones with just a hint of warmth. Where oversaturation is most problematic is on Caucasian skin tones, as it's very easy for these "memory colors" to be seen as too bright, too pink, too yellow, etc.
Hue. Though the Canon SD870 IS pushed reds toward orange slightly and cyans toward blue by quite a bit, overall results are pretty accurate, and its color is quite pleasing. The other important part of color rendition is hue accuracy. Hue is "what color" the color is.
| See full set of test images
See thumbnails of all test and gallery images
Exposure and White Balance
Indoors, incandescent lighting
Good color with the Manual white balance setting. Average positive exposure compensation required.
|Auto WB +1.0 EV||Incandescent WB +1.0 EV||Manual WB +1.0 EV|
Color balance indoors under incandescent lighting was just a hint warm with the Auto white balance setting, but more magenta and pink with the Incandescent option. Results are just a little pinkish with the Manual white balance, but overall color is the most accurate. The Canon SD870 IS performed pretty well in terms of exposure, requiring an average amount of positive exposure compensation for this shot, at +1.0 EV. Despite the slight pink tint in Marti's skin tones, overall color with the Manual white balance setting looks good, though the blue flowers do show some slight purplish tints. (Many digital cameras have trouble here.) Our test lighting for this shot is a mixture of 60 and 100 watt household incandescent bulbs, a pretty yellow light source, but a very common one in typical home settings here in the U.S.
Slightly better than average exposure accuracy. Bright colors outdoors with good hue accuracy.
|Auto White Balance,
|Auto White Balance,
Outdoors, the Canon SD870 IS performed well, with good overall color and exposure. The outdoor house shot has vibrant greens and good overall color balance. Detail is strong in both the highlights and shadows.
Lowest Contrast Setting,
Low Contrast Setting,
Normal Contrast Setting,
In the Outdoor Portrait, the Canon SD870 handled the harsh lighting pretty well, requiring less than the average amount of exposure compensation. The default contrast is slightly high, but the camera's adjustable contrast setting did help to decrease contrast while dimming the exposure slightly. It also managed to increase detail in the lighter shadows as well. Overall, good performance.
High resolution, 1,450 ~ 1,500 lines of strong detail.
|Strong detail to
1,500 lines horizontal
|Strong detail to
1,450 lines vertical
Our laboratory resolution chart revealed sharp, distinct line patterns down to about 1,500 lines per picture height horizontally, and to about 1,450 vertically. Extinction occurred beyond the 2,000 line limit of our test target. 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.
Sharpness & Detail
Sharp images overall, with excellent detail. Minimal edge enhancement on high contrast subjects, and only slight noise suppression artifacts in the shadows.
|Very good definition of high-contrast elements, though with slightly visible edge enhancement.||Subtle detail: Hair
Noise suppression tends to blur detail in areas of subtle contrast, as in the darker parts of Marti's hair here.
Sharpness. The Canon PowerShot SD870 IS captures sharp images with very nice detail. Some edge enhancement artifacts are visible on high-contrast subjects such as the crop above left, but results are still quite good, and the camera does an excellent job of preserving fine detail. Edge enhancement creates the illusion of sharpness by enhancing colors and tones right at the edge of a rapid transition in color or tone.
Detail. The crop above right shows a small amount of noise suppression, though detail is quite good in the shadows (better than average). 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.
ISO & Noise Performance
Low to moderate noise at the normal sensitivity settings, though a big jump in noise with very strong blurring at the high settings.
|ISO 80||ISO 100||ISO 200|
|ISO 400||ISO 800||ISO 1,600|
Noise levels are low to moderate at the Canon SD870 IS's lower sensitivity settings, with slightly higher noise at ISO 200. At ISO 400, noise pixels brighten and noise reduction smudges fine detail. At ISO 800, the resulting grain pattern eliminates much of the finer details, and gives the image a blotchy, stippled effect. At ISO 1,600, noise is so strong that fine detail is completely lost.
Extremes: Sunlit and low light tests
High resolution with strong overall detail. Slightly high contrast, though still pretty good shadow detail. Very good low-light performance, capable of capturing bright images in near darkness.
|+0.3 EV||+0.7 EV||+1.0 EV|
Sunlight. The Canon PowerShot SD870 IS performed pretty well under the harsh lighting of the test above, though it produced slightly high contrast with dark shadows. However, detail is reasonable in the shadows, even without the low contrast adjustment. The camera's contrast adjustment did taper down contrast somewhat, though it dimmed the exposure as well. Some areas look a little dark at +0.7 EV, but I felt the highlights were too strong at the +1.0 EV setting.
Note: 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.) 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.
Low light. The Canon PowerShot SD870 IS captured bright images down to the 1/16 foot-candle light level (about 1/16 as bright as average city street lighting at night) at all of its sensitivity settings, except for ISO 80 and 100. Color balance looks good with the Auto white balance setting, without any strong color shifts from the dim lighting. The camera's autofocus system also performed well, able to focus unassisted down to almost 1/16 foot-candle, the lowest level we test at. Do keep in mind though, that the very long shutter times necessary here absolutely demand the use of a tripod or other camera support to get sharp photos. (A useful trick is to just prop the camera on a convenient surface, and use its self-timer to release the shutter. This avoids any jiggling from your finger pressing the shutter button, and can work quite well when you don't have a tripod handy.)
How bright is this? The one foot-candle light level that this test begins at roughly corresponds to the brightness of typical city street-lighting at night. Cameras performing well at that should be able to snap good-looking photos of street-lit scenes.
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
Uneven coverage at wide angle. Somewhat dim exposure at the default exposure setting, requiring an average amount of exposure compensation. Pretty good range.
|28mm equivalent||105mm equivalent|
|Normal Flash +1.0 EV||Slow-Sync Flash +1.0 EV|
Coverage. Flash coverage was uneven at wide angle with dark areas in the corners of the frame. At telephoto, coverage was more even, though the exposure was more dim overall. Indoors, under incandescent background lighting, the Canon SD870 IS's flash underexposed our subject at its default setting, requiring a fairly typical +1.0 EV exposure compensation adjustment to get bright results. The camera's Slow-Sync flash mode also required an average amount of positive compensation at +1.0 EV, though overall coverage is more even. However, the longer shutter speed results in a strong orange cast from the background lighting.
ISO 100 Range. The Canon SD870 IS's flash was pretty bright and powerful, with good intensity out to about 12 feet at wide angle and ISO 100. At telephoto, however, it never really reached a good exposure, even at 6 feet. It would probably be acceptable, depending on the subject between 6 and 8 feet, but mildly underexposed overall.
|Manufacturer-Specified Flash Range|
Auto ISO 200
Auto ISO 200
Manufacturer Specified Flash Test. In the shots above, the Canon SD870 IS seems to perform exactly as Canon says it will, though the camera boosts the ISO to 200.
Note: Our standard test method for flash range uses a fixed setting of ISO 100, to provide a fair basis of comparison between cameras. We've now also begun shooting 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.
Good print quality, great color, good 11x14 inch prints up to ISO 400. ISO 800 images are grainy but usable at 8x10, ISO 1,600 shots are contrasty and grainy but usable at 5x7 and 4x6.
With the Canon PowerShot SD870 IS, we found that it had enough resolution to make good looking 11x14 inch prints. At 13x19, its prints were softer, but probably fine for wall display. Chroma noise sneaks into the shadows starting at ISO 200, but it's not noticeable at arm's length at this size. 11x14 inch prints were usable up to ISO 400. Results are better for 400 and 800 at 8x10. At 5x7 and ISO 800, you don't notice it's a high ISO shot. ISO 1,600 is grainy, at 5x7, but still looks good. At 4x6, it's hard to tell it's a high ISO shot. If you hope to enlarge at all, I recommend you stick to ISO 800 and below, especially indoors, which presents more of a challenge to the sensor.
Note: 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 Pro 9000, and on the Canon MP610 here in the office. (See the Canon PIXMA Pro 9000 review for details on that model.)