Canon S100 Exposure

Saturation & Hue Accuracy
Very good overall color and hue accuracy.

Saturation. The Canon S100 produced good saturation overall, with minor to moderate oversaturation in reds, greens, browns, blues and purples. Some colors such as bright yellow, aqua and cyan were actually undersaturated by a small amount. Average saturation was 110.7%, or 10.7% oversaturated, which is fairly typical for a compact camera. Overall, the Canon S100's images appeared to have natural looking color that wasn't too vivid, and you can always adjust saturation to your liking. 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. Here, when using Manual white balance in simulated daylight, the Canon S100 also did well, producing natural-looking skin tones, though just slightly on the pink side. With Auto white balance, lighter skin tones were a little yellow and flat. 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 PowerShot S100 produced a few color shifts relative to the correct mathematical translation of colors in its subjects, most visibly pushing cyan toward blue (probably for better-looking skies), red toward orange, and yellow toward green. Mean "delta-C" color error after correcting for saturation was excellent though, at only 4.12; much better than average. Hue is "what color" the color is.

Exposure and White Balance

Indoors, incandescent lighting
Slight yellow/green cast with Auto and Manual white balance, though Auto is better than average. Slightly better than average exposure accuracy.

Color balance indoors under incandescent lighting had a slight yellow/green cast with the Auto white balance setting, but was pretty good. The Canon S100 did better here than the majority of digital cameras we test. The Incandescent white balance option resulted in a fairly strong pinkish cast. The Manual white balance setting produced fairly accurate color, though a touch cool also with slightly green bias. The PowerShot S100's exposure system handled this lighting well, producing good results with with no exposure compensation. (The average for this shot is + 0.3 EV.), though the manual white balance exposure was a little brighter than the others. 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
Good color, but high default contrast can make for tricky exposures.

The Canon PowerShot S100 performed reasonably well under harsh outdoor lighting for its class, though default contrast was quite high. Slightly above average exposure compensation of +1.0 EV was needed to keep the model's facial skin tones bright, resulting in quite a few blown highlights in her shirt and flowers. Most cameras require about +0.7 EV. On the other hand, overall exposure was very good in the outdoor far-field shot at the default exposure, with just a few clipped highlights and lost shadows. Color outdoors is good with the Auto white balance setting, though we preferred Manual white balance for our Outdoor Portrait shot, as Auto rendered skin tones a little too flat and yellow. Though contrast is high, the shadows hold onto a fair amount of detail. Fortunately, there's a contrast adjustment to help tame the highlights a bit, though it works better at bringing out shadows. (See below.)

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Resolution
High resolution, 1,700 lines of strong detail from in-camera JPEGs, 1,800 to 1,900 lines from converted RAW files.

Our laboratory resolution chart revealed sharp, distinct line patterns down to about 1,700 lines per picture height in both the horizontal and vertical directions in JPEGs straight out of the camera. (Some might argue for over 1,800 lines, but artifacts such as moire patterns begin to appear at much lower resolutions.) Extinction of the pattern occurred between 2,400 and 2,600 lines. Adobe Camera RAW 6.6 was able to extract significantly more resolution (1,800 to 1,900 lines per picture height), but also showed more color moire and didn't do as well as the camera at reducing the visibility of defective pixels. 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
Fairly sharp, detailed images overall, with only minor edge-enhancement on high-contrast subjects. Noise suppression limits definition in low contrast areas, though better than average results here.

Sharpness. The Canon PowerShot S100 captures very good detail and fairly sharp JPEG images at default settings. Only slight enhancement artifacts are visible on high-contrast subjects such as the crop above left.. Very good results here. 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 levels of noise suppression, as the low contrast areas of hair show less distinct detail. However, many individual strands remain fairly well defined, so performance here is actually better than average for a compact digicam. 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 S100 produces fairly sharp, detailed in-camera JPEGs. With a good RAW converter, more detail can be extracted, though. See below:

In the table above, mousing over a link at the bottom will load the corresponding crop in the area above, and clicking twice will open the full resolution image.

The image on the left is a crop from an in-camera Fine JPEG taken with default settings. The image in the center is a RAW file processed using Canon's included Digital Photo Professional software, using default settings. The right-most image was converted with Adobe Camera RAW 6.6 then sharpened in Photoshop with an unsharp mask of 500% and radius 0.3. As you can see, Canon's Digital Photo Professional  software wasn't really able to extract more detail than the in-camera JPEG, as it appears to apply some significant noise reduction under the hood. It also applies more sharpening than the camera default, leaving more noticeable sharpening halos. The ACR converted image reveals more fine detail than both the other images, but at the cost of showing more noise. Still, shooting RAW and using a good quality RAW converter gives you control over the detail versus noise tradeoff as well as other benefits such as highlight recovery, exposure adjustment, white balance, output format, etc.

ISO & Noise Performance
Low noise at the normal sensitivity settings, with pretty good results up to ISO 400. Strong noise and loss of detail at higher settings, however.

The PowerShot S100 produced low to moderate noise at the lower sensitivity settings, though the effects of noise reduction such as smudging and loss of fine detail can already be seen even at the lowest ISO if you look carefully. Fine detail was quite strong up to ISO 200, though. At ISO 400, noise was still quite reasonable and a lot of fine detail remained intact, but additional smudging was evident as well as chroma noise in the shadows.  Fine detail really starts to take a big hit at ISO 800, and chroma noise in the form of yellow splotches is more evident not just in the shadows, but in midtones as well. ISO 1,600 was softer from more aggressive noise reduction, as one would expect. At ISO 3,200 and above, luminance noise becomes much more visible, along with stronger chroma noise especially at ISO 6,400. Still, overall handling of detail versus noise is better than the typical compact camera, similar to if not a bit better than the S95 at higher ISOs. To see how these images held up to printing at various sizes, read the Output Quality section below.

Extremes: Sunlit and low light tests
High resolution with strong detail, though high default contrast doesn't make the best of the available dynamic range. Fair low-light performance, capable of getting bright images in near darkness at some ISOs, though autofocus struggled.

Sunlight. The Canon PowerShot S100 struggled a bit under the deliberately harsh lighting in the test above. To keep facial tones bright +1.0 EV compensation was require, but that led to a lot of washed-out highlights. Detail was pretty good in the shadows, though. Some may prefer the +0.7 EV setting for its reduced highlight clipping, but we found the face a bit too dim. The PowerShot S100 offers five contrast levels settings, but as mentioned previously they work better at lightening shadows than reducing clipped highlights, so be sure to adjust your exposure accordingly. Also consider using fill flash in situations like the one shown above; and it's better to shoot in the shade when possible.

As part of the S100's Intelligent Contrast (i-Contrast) feature, the camera has "Dynamic Range Correction" to tame highlights, and "Shadow Correct" to bring out more shadow detail.

Above are examples of our "Sunlit" Portrait scene shot with the S100's four available i-Contrast settings. Mouse over the links about right to compare, and click on the links to get to the full-resolution images. The resulting images are a little dim at +0.3 EV exposure (in hindsight, it would have been better to shoot these at +0.7 or +1.0 EV compensation), but you can see that highlights were toned-down progressively with the DR 200% and DR 400% settings. The results with DR Auto were very similar to it being set to Off since few highlights were blown to begin with at +0.3 EV. Shadow Correct worked well to boost the shadows without impacting highlights, leading to the best overall exposure here.

Note that Dynamic Range Correction may boost ISO depending on your current setting, so more noise and/or stronger NR may be visible with it enabled. (In our samples above, DR 200% used ISO 160 and DR 400% used ISO 320, while DR Auto and Shadow Correct left ISO at 80.)

The table above shows results with the default exposure using Aperture Priority AE, as well as Face Detection enabled and Smart Auto. As you can see, the S100's face detection and Smart Auto mode both improved exposure automatically compared to the default exposure in Aperture Priority mode, going from very underexposed to usable images. Face detection dropped the shutter speed from 1/80s to 1/30s to improve the exposure for the face, while keeping ISO (80) and aperture (f/5.6) the same as before. Smart Auto also detected the face, but boosted ISO to 500, used a larger aperture (f/5.0) and a faster shutter speed (1/200s). Overall, we preferred the Smart Auto image as the camera also applied some Intelligent Contrast resulting in far fewer blown highlights and more open shadows, but there is some detail loss due to the higher ISO.

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.)

Low Light. The Canon PowerShot S100 did fairly well overall in our low-light tests, though shutter speed limitations prevented us from capturing a full matrix of low light images here. The S100's longest shutter speed is 15 seconds which resulted in a dim image at our lowest light level of 1/16 foot-candle at ISO 80, and shutter speeds longer than 1.3 seconds are not supported at ISOs other than 80 (which is why there are no ISO 100 and 200 rows in the table above). Noise is very well controlled to ISO 400, and color balance looks good though slightly cool with the Auto white balance setting. The camera does have some special low light modes such as Hand-held NightScene mode which combines several images to reduce noise and keep the shutter speed relatively high, though results were dim in our test here.

The camera's AF system was only able to focus unassisted to just below the 1/2 foot-candle light level in our tests, which is rather poor given the relatively bright lens. (The S95 managed to focus to below 1/16 foot-candle on the same subject.) The S100 was however able to focus in complete darkness with the aid of its AF assist lamp.

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.) 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
A reasonably powerful flash for its size, with uneven coverage at wide-angle. Good exposure from Auto flash mode in our indoor portrait test shot.

Coverage and Exposure. Flash coverage was quite uneven at wide-angle, with much more uniform results at full telephoto. The S100's flash didn't have enough power to properly expose our Indoor Portrait scene at ISO 100 even with flash exposure compensation, but that's no surprise given the size of the flash. Slow-sync flash mode helped, producing a brighter image that captured more ambient light, but the slow shutter speed of 1/5 second would require the use of a tripod and a very still subject. The white balance here is actually pretty good, as slow-sync mode normally produces quite an orange cast. We can attribute the improved flash white balance to the new DIGIC 5 processor. Auto flash mode however did a good job with our indoor flash portrait test, resulting in a bright image at ISO 320 (automatically selected). The S100 used a fairly slow shutter speed of 1/25 second however, which could still lead to some issues with subject motion blur.

ISO 100 Range. At wide-angle and ISO 100, flash shots were bright to about 11 feet (thanks to the S100's bright f/2.0 lens), decreasing in brightness from that point on. At full telephoto, flash shots started out quite dim at 6 feet, and got darker from there.

Manufacturer Specified Flash Test. Canon rates the PowerShot S100's flash range at 7 meters / 23 feet at wide-angle and 2.3 meters / 7.5 feet at telephoto, when using Auto ISO. In the shots above, the PowerShot S100's flash performs to Canon's specifications, producing bright images at wide-angle and full telephoto, though the camera boosted ISO to 640 in both cases.

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 shoot 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.

Print Quality: ISO 80 and 100 look great at 13 x 19 inches, and make a nice wall display print at 16 x 20.

ISO 200 also looks quite nice at 13 x 19 inches.

ISO 400 images are usable for wall display at 13 x 19, but softness in the red channel is more noticeable. Reduction to 11 x 14 looks a lot better.

ISO 800 shots are soft at 11 x 14. They look quite good at 8 x 10, with the exception of a slight loss of contrast in our red swatch.

ISO 1,600 images are good at 5 x 7 and usable at 8 x 10 for less critical applications.

ISO 3,200 shots are soft at 8 x 10, looking more like a watercolor painting. They look better at 5 x 7, if still a bit soft in our red swatch.

ISO 6,400 files are usable at 4 x 6, but appear a little flat in the colors.

Pretty good quality overall, a general repeat of what we saw with the S95, though with a little better performance at ISO 1,600 and 3,200, and of course the new 6,400 setting.

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 Mark II studio printer, and on the Canon Pixma MP610 here in the office. (See the Canon Pixma Pro9000 Mark II review for details on that model.)