Canon XS Image Quality

Saturation & Hue Accuracy
Accurate color with minor oversaturation of strong reds and blues.

Saturation. The Canon XS pushes reds and blues just a bit, and undersaturates some greens, but overall saturation is quite accurate, especially for an entry-level model. 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. Caucasian skin tones from the XS lean toward the warm side. Some users would call this "a healthy glow;" we found it natural and pleasing. 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. The Canon XS showed a few small color shifts relative to the correct mathematical translation of colors in its subjects, but had excellent accuracy overall. Most noticeable was a shift in reds toward orange, and orange toward yellow, with some shifts in greens and cyans as well. Hue is "what color" the color is.

Saturation Adjustment
The Canon XS has a total of nine saturation settings available, four above and two below the default saturation. This covers a very wide range of saturation levels, about as wide a range as you're likely to find photographically relevant, apart from special effects that are arguably better achieved in software. The fine steps between settings mean you can program the camera to just the level of saturation you prefer. Nice.

The table above shows results with the default as well as the two extreme saturation settings. Click on any thumbnail above, then click again to see the full-sized image.

Exposure and White Balance

Indoors, incandescent lighting
Good color with the Manual white balance setting, though warm results with Auto and Incandescent. Average positive exposure compensation required.

Indoors, under normal incandescent lighting, color balance was very warm with the Auto white balance setting. The Incandescent setting was better, but still too warm for our tastes. Some users may actually prefer this, as being more representative of the original lighting, but we found the Manual setting produced the most accurate results. The Canon XS required an average amount of positive exposure compensation here, at +0.3 EV. Despite the (very) slight warm cast, overall color with the Manual white balance setting looks quite good, though the blue flowers appear very purple, and the greens are a bit dark. (Many digital cameras reproduce these flowers with a dark, purplish tint, so the Canon XS actually performs a little better than average 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.

Outdoors, daylight
Bright colors overall, though a tendency toward a warm cast and slightly high contrast under harsh lighting. Better than average exposure accuracy.

Outdoors, the Canon XS tended toward a warmer color balance, though overall color was pretty good. The Rebel XS performed a bit better than average in terms of exposure, requiring slightly less than the typical amount of positive compensation we're accustomed to seeing among consumer digital cameras. (And the far-field shot of the house came out just about ideal at the XS's default exposure setting.) The Rebel XS's default contrast is a little high, producing washed-out highlights and dark shadows under the deliberately harsh lighting of our "Sunlit" portrait test shown above left. The camera's contrast and highlight tone priority settings do tame the highlights and shadows though (see below).

See full set of test images with explanations
See thumbnails of all test and gallery images

Resolution
Very high resolution, 1,600 lines of strong detail from in-camera JPEG, about the same from processed RAW file.

Our laboratory resolution chart revealed sharp, distinct line patterns down to about 1,600 lines per picture height horizontally and in the vertical direction. Extinction didn't occur, though lines began to merge at around 1,800 - 1,900 lines per picture height. When processing the XS's CR2 files using Adobe Camera Raw, we got very similar results. 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.

See full set of test images with explanations
See thumbnails of all test and gallery images

Sharpness & Detail
Sharp images overall, though slight edge-enhancement artifacts on high-contrast subjects. Moderate (for an SLR) noise suppression visible in the shadows.

Sharpness. The Canon XS captures fairly sharp images overall, though some minor edge enhancement artifacts are visible on high-contrast subjects such as the crop above left. Note also that sharpness is set to slightly soft by default. 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 moderate noise suppression artifacts in the darkest areas of the model's hair, blurring and smudging individual strands together. There is also some chroma noise visible in the shadows, unusual at ISO 100. The camera's overall response here is below average for an SLR, and quite disappointing. 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.

RAW vs In-Camera JPEGs
As noted above, the Canon XS does a pretty good job at balancing between sharpness and visible sharpening artifacts in camera JPEGs. As is usually the case though, a little more detail can be obtained from carefully processing RAW files. Take a look below, to see what we mean:

In the table above, mousing over a link at the bottom will load the corresponding crop in the area above. You can also click on a link to view the entire image. Examples include in-camera Fine JPEG, RAW file processed through Canon's Digital Photo Professional (DPP) software with additional light sharpening (USM 100%, 0.3 pixel radius) applied in Photoshop, and RAW file processed through Adobe Camera Raw version 5.0, then sharpened in Photoshop. (For the Canon XS's converted images converted via ACR, I found best results with 300% unsharp masking with an 0.3 pixel radius, though some very fine "jaggies" do appear when sharpening that much.)

Note: ACR renders colors somewhat differently than either the XS or the Canon software, so the greens in the trees are rather different. There's no mistaking the increase in detail though, regardless of changes in color or tone.

ISO & Noise Performance
Low image noise overall, but some loss of detail and demosaicing errors at all ISOs.

The Canon Rebel XS produced low image noise overall, however we were surprised to see what looks like chroma noise and blurring in darker areas of the model's hair, even at the base ISO. At low ISOs, the "chroma noise" is likely caused by color moiré interference patterns, as there is no sign of it in darker regions that have less detail. Noise remains fairly low up to ISO 400, but more smudging and actual chroma noise is visible at ISO 800 and especially ISO 1,600.

There were also what look to be demosaicing errors in areas of fine detail and high contrast, such as the hair on the model's forehead at lower ISOs, appearing in the upper right corner of the crops displayed here. You can see some moiré and aliasing issues in our Multi, Still Life, and Low Light shots as well. It seems the XS's sensor may need a slightly stronger low-pass filter to avoid those artifacts with fine detail. As always, see the Print Quality section below, to find out what the recommended maximum print size is at each ISO setting.

Extremes: Sunlit and low light tests
Very high resolution with strong overall detail, but slightly high contrast with strong highlights. Very good low-light performance, able to capture bright images to the lowest limits of our test.

Sunlight. The Canon XS produced high contrast with slightly washed-out highlights and deep shadows under the harsh lighting of the test above. However, shadow detail is pretty good. The model's face was a little dim at the +0.3 EV setting, so we preferred the image with +0.7 EV of exposure compensation, despite the clipped highlights in her shirt. Compensation of +1.0 EV resulted in too many clipped highlights for our tastes. (In real life, be sure to use fill flash in situations like the one shown above; it's better to shoot in the shade when possible.)

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.)

Contrast Adjustment
We really like it when a camera gives us the ability to adjust contrast and saturation to our liking. It's even better when those adjustments cover a useful range, in steps small enough to allow for precise tweaks. As was the case with its saturation adjustment, the Canon XS's contrast setting meets both challenges very well.

At its lowest contrast setting, the Canon XS did an excellent job of preserving highlight detail, maintaining fairly natural-looking (if just slightly pink) skin tones, and holding nice detail in the shadows. The XS captures good color outdoors, though again, just slightly on the warm side. Overall, very good results here, especially when the contrast setting is tweaked.

The table above shows results with the default as well as the two extreme contrast settings. While you can see the extremes, it's hard to really evaluate contrast on small thumbnails like these, click on any thumbnail to go to the full-size image. The Canon XS's contrast adjustment worked well, with little effect on color saturation. Contrast and saturation are actually fairly closely coupled adjustments, it's a good trick to be able to vary one with out the other changing as well. Canon did a good job here.

Automatic Lighting Optimization

We found the effect from Canon's Automatic Lighting Optimization feature to be quite subtle. You can see the image with ALO on is slightly brighter than with it off. We did see a slight improvement in detail and noise levels in the deep shadows, but had to really play with the image's tone curve to be able to see its effect. (It's possible that ALO might have more effect in the case of significant exposure errors, but we didn't test that situation directly.)

Low light. The Canon XS performed very well on the low-light test, capturing usable images at the lowest light level (1/16 foot-candle), even with the lowest sensitivity setting (ISO 100). Noise increases as ISO goes up and light levels go down, but remains fairly low, even at higher sensitivities. There are no sign of hot pixels, even when NR is set to Off, but some very slight banding can be detected in the shadows at higher ISOs. Color balance looked very good with the Auto white balance setting. The camera's autofocus system was able to focus on the subject to just below the 1/8 foot-candle light level unassisted, and in complete darkness with the AF assist enabled. Keep in mind that the longer shutter speeds here demand the use of a tripod to prevent any blurring from camera movement. (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 level 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.) Digital SLRs like the Canon XS do much better than point & shoots, but you still shouldn't expect a quick autofocus lock with moving subjects.

Print Quality
Great print quality, good color, sharp 13 x 19-inch prints.

The Canon XS's printed output is quite good, able to output usable 13 x 19-inch prints at ISO 100. They're a little over-sharpened, but still good. 13x19-inch prints are a little better. ISO 200 shots print the same as 100, producing a good 16x20 or great 13x19. ISO 400 images do just fine at 13x19, and of course are better 11x14, but not by much. ISO 800 shots are still quite good at 11x14, with only a little chroma noise in dark areas. ISO 1,600 shots really look good at 11x14. Yes, there's some chroma noise in darker areas, and it becomes noticeable in the bottles of the Still Life shot, but still not bad. At 8x10, that chroma noise is only noticeable on close inspection; though the contrast is increased somewhat.

Detail throughout the ISO range remains surprisingly strong. I'd like to see a little more detail at the lower ISO settings, but you can raise in-camera sharpening to achieve that, or sharpen after. An excellent performance that should make you confident to shoot at any ISO setting, in just about any kind of light, Tungsten included.

Demosaicing errors do appear in large prints, including the color errors and diagonal lines that are discussed in the User Report. The chroma noise is actually the worse of the two, noticeable even at 8x10 (to the trained eye), while the diagonal line errors don't really have an impact on the image until 13x19-inch print sizes, and even then they're only noticeable on close inspection.

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 Pro9000 studio printer, and on the Canon iP5200 here in the office. (See the Canon PIXMA Pro9000 review for details on that model.)