Casio EX-S10 Exposure

Saturation & Hue Accuracy
Pretty good overall color and hue accuracy, though a few color shifts and some slight oversaturation.

Skin tones. The EXILIM CARD EX-S10's skin tones range on the pinkish/reddish side, which was noticeable in a few images. Many consumers prefer warmer skin tones, but in the EX-S10's case, some may find skin tones just a little too pink. 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 EXILIM CARD EX-S10 showed several color shifts relative to the correct mathematical translation of colors in its subjects. Reds were pushed toward orange, orange toward yellow, and yellow toward green. Cyan tones were also pushed toward blue. (As noted below in the Output Quality section, we found the color shift of yellows most noticeable.) Hue is "what color" the color is.

Exposure and White Balance

Indoors, incandescent lighting
Best color with Manual white balance, though a hint cool. Slightly more than average positive exposure compensation required.

Color balance indoors under incandescent lighting was quite warm in both the Auto and Incandescent white balance modes, the Manual option producing more accurate results. The white value in Manual mode is pretty close to accurate, but the resulting image does feel a little cool. Overall color is good, but skin tones are slightly cool, and the red flowers have an orange tinge. (Perhaps more a result of the red to orange color shift we noted in the color accuracy analysis than any artifact of the light source here.) The Casio S10 required a +0.7 EV exposure compensation boost to get a good exposure, a little more than average for this shot. 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
Slightly high contrast, but generally good exposure and color.

Outdoors, the Casio EXILIM CARD EX-S10 produced good overall color and exposure, though results were slightly contrasty when it had to deal with harsh lighting. In direct sun, the S10 tends to lose detail in strong highlights, but does a pretty good job with the shadows, albeit with some loss of definition there from noise and noise suppression. Skin tones in the outdoor portrait are a little pinkish, but overall color in both images still looks pretty good. The EX-S10 does feature an adjustable contrast setting, as well as a dynamic range optimizer, both of which can help with exposures under conditions like these. (See examples of both in the section below, titled "Extremes.")

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

Resolution
Very high resolution, about 1,500 lines of strong detail.

Our laboratory resolution chart revealed sharp, distinct line patterns down to about 1,500-1,600 lines per picture height horizontally, and to about 1,400 lines vertically (some may argue for 1,500). Extinction didn't really occur on our 1x resolution target, though lines began to merge slightly around 1,900 lines. 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 details in areas of high contrast, with some evidence of edge-enhancement. Areas of subtle detail show less definition, with marked detail loss from noise suppression.

Sharpness. The Casio EXILIM CARD EX-S10 does a good job of capturing fine detail, though some "halo" artifacts are evident from the camera's edge enhancement, as in the crop above left. 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 substantial loss of detail from the camera's noise suppression, as seen in the image crop above right: In areas where the local contrast is low (as in the subtle tonal variations in the mannequin's hair), the Casio S10's noise reduction processing blurs the image in an attempt to remove the image noise. 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
Moderate noise at the normal sensitivity settings, though stronger noise and noise suppression artifacts at the higher settings, with noticeable loss of detail.

The Casio EXILIM CARD EX-S10 produced moderate noise at its lower sensitivity settings, with moderate noise suppression even at the lowest setting (ISO 50). At ISO 400, noise level becomes higher, progressing to a very strong pattern at ISO 1,600. The camera's attempts at noise suppression also increase, resulting in some loss of detail.

It's important to note here, though, that we're pixel-peeping terribly: As we'll see below in the Output Quality section, when you shrink the Casio S10's 10 megapixels of resolution down to reasonable print sizes, the noise becomes much less apparent.

Extremes: Sunlit and low light tests
High resolution with strong overall detail, but high contrast. Limited low-light capabilities, fair exposures under normal city street lighting conditions.

Sunlight:
The Casio EXILIM CARD EX-S10 produced high contrast under the deliberately harsh lighting in the test above, with washed-out highlights and deep shadows. Though contrast is high, detail remains pretty good in the shadows, albeit with interference from noise suppression which limits definition. At +0.7 EV, the highlights on the white shirt are a bit hot, but the exposure at +0.3 EV proved too dim for good skin tones. The camera does offer adjustable contrast and a dynamic range optimizer, both of which attempt to produce a more balanced exposure in situations like this. Still, be sure to use fill flash in situations like the one shown above; and it's better to shoot in the shade when possible.

Contrast & Dynamic Range Adjustments

The Casio S10 does provide some control over the camera's contrast, and offers a dynamic range expansion option that's handy for dealing with conditions of extreme tonal range. The contrast adjustment seems to work mainly by opening up (lightening) the shadows; in the shots above, we'd probably have wanted to decrease the overall exposure to take advantage of this. (Since we were shooting across the full range of the contrast settings though, we left it at the nominal setting, so the shadows on the high-contrast sample wouldn't be more badly plugged than they already were.) The Dynamic Range expansion option has somewhat the same effect, but boosts saturation a little bit, to avoid the slightly washed-out look of the low contrast setting.

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 Casio EXILIM CARD EX-S10 had some trouble in low lighting, only capturing bright images at the lowest light level at its ISO 800 and 1,600 settings. At the lower settings, the target was visible at the lowest light level, but quite dim. Exposures under average city street lighting at night (the highest level in this test, about one foot-candle) weren't too bad across the board, though color balance was a bit cool in the Auto setting. The camera's AF system struggled to focus at these light levels, so manual focus was used. Keep in mind that the longer shutter times require the use of a tripod to prevent blurring from camera movement. Alternatively, you can always brace the camera against a wall or other solid structure, depending on the shutter speed.

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 weak flash with limited range. Our standard shots were quite dim, and exposure compensation had no effect.

Flash coverage was uneven at wide angle, with about average falloff in the corners of the frame. At full telephoto, coverage was more uniform, but flash power was quite weak. In the Indoor test, the EXILIM CARD EX-S10's flash underexposed our subject quite a bit at its default setting, and boosting the exposure compensation didn't brighten the image at all. The camera's Slow-Sync flash mode produced similar results, though in this case, a boost to +0.3 EV did show a tiny increase in brightness. Not favorable results here.

ISO 100 Range. At wide angle and ISO 100, flash shots were a little dim at 6 feet, but maintained that intensity to about 8 feet. At telephoto, shots were fairly dark at 6 feet and decreased in brightness from there.

Manufacturer Specified Flash Test. In the shots above, the EXILIM CARD EX-S10 performs about as Casio says it will, though intensity is low. However, it should be noted that the camera's Auto ISO setting only increased sensitivity to 200 at wide angle to get what it considers bright results, and at telephoto, ISO is at a normal 100 setting. 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.

Print Quality
Good print quality, good color, decent 13x19 inch prints, sharp 11x14 inch ones. ISO 800 images are soft and noisy but usable at 8x10, ISO 400 shots make surprisingly good-looking 8x10s.

The Casio EX-S10 had enough resolution to make 13x19 inch prints sharp enough for mounting on a wall and viewing at a distance of a foot or two, while 11x14 inch prints from its images were quite sharp indeed. At higher sensitivity settings, shots at ISO 800 made somewhat soft and noisy 8x10 inch prints, but we think many consumers would find them perfectly acceptable to frame and display on a table or wall. ISO 400 shots made surprisingly nice-looking 8x10s. At ISO 1,600, the Casio S10's images were usable only to 5x7 inches, and looked better as 4-6s.

Color-wise, the Casio S10's images made bright, colorful prints that we think most consumers would find appealing. That said, the color shifts we saw with Imatest in the lab also showed up in other shots. (Interestingly, Imatest showed the greatest color shifts in oranges, which were shifted toward blue, but the color shift we were most aware of was in strong yellows, which tended to have a slightly greenish tinge.)

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.)