Pentax A10 Exposure

Saturation & Hue Accuracy
Generally good color, but larger than average hue shifts and a slight tendency toward cooler color balances outdoors. Good saturation overall, cool skin tones.

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 Pentax Optio A10 oversaturates slightly (a typical amount for consumer cameras), though in some cases, it may visually appear to undersaturate. Reds and greens in particular are very technically accurate, but that may make them appear dull when compared with images from competing cameras. 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. Here, the Optio A10 tended to produce a slight blue-magenta cast in skin tones, which is less flattering than too much warmth. The cool cast isn't strong enough to produce adverse results, but consumers drawn to warmer skin tones may want to tweak the color balance post capture. (Though that said, skin tones captured with the Manual white balance option were generally warmer.)

The other important part of color rendition is hue accuracy. Hue is "what color" the color is. The Optio A10 did show a tendency toward cooler color balances, particularly outdoors. It pushed cyan toward blue, blue toward violet, and yellows toward green, making its color less accurate than that of many competing models. Overall color was still pleasing, but reds definitely looked dull when compared to other cameras' output.

Exposure and White Balance

Indoors, incandescent lighting
Slight color casts with each white balance setting, though nearly accurate results with Manual, and Auto did better than average. About average exposure compensation for the main shot, though other white balance settings required much more.

Both the Auto and Incandescent white balance settings had trouble indoors under incandescent lighting, producing warm and magenta color casts respectively, but results with the Auto setting were better than most cameras we test manage in Auto mode. With the Manual white balance option, color was closest to accurate, but a slight yellow cast is present, with pinkish-magenta tints visible in some areas. The net effect though, was to preserve a little of the warmth of the original lighting though, without overdoing it. In the Manual white balance mode, the Optio A10 only required a +1.0 EV exposure boost, while the Auto and Incandescent settings required a +1.7 EV exposure adjustment. Though the overall exposure looks about right at +1.0 EV in Manual mode, the white shirt does have a few overly "hot" highlights. The slight yellow color cast in Manual mode flattens color somewhat, and the blue flowers in the bouquet are very dark and purplish. (A common problem with 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
High contrast under harsh lighting, though moderate shadow detail. A tendency toward a cooler color balance with Auto white balance, and somewhat dark-looking color overall.

Outdoors, the Pentax Optio A10 produced high contrast, especially under harsh lighting. In the Outdoor Portrait above, the high contrast also resulted in distinct tonal variations in skin tone (with strong magenta tints and stark contrasts in tone). The camera's Low Contrast adjustment did tone things down slightly, though the images became darker as a result and the tonal variations in the skin did not improve. The camera's Auto white balance setting tended toward a cooler color balance in daylight, but the Manual option warmed things up a little in the Outdoor Portrait. Shadow detail was pretty good though definition was broken up by image noise. Still, the Optio A10 did hold onto a fair amount of detail even in the deep shadows.

See full set of test images with explanations
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Resolution
High resolution, ~1,500 lines of strong detail.

Our laboratory resolution chart revealed sharp, distinct line patterns down to about 1,450 lines per picture height in the vertical direction, 1,600 lines along the horizontal axis, with extinction past the 2,000 line point. 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. Beware that while you might be able to make out what looks like distinct lines at numbers higher than those we've mentioned here, the camera is just doing its best to continue interpreting the lines. If you zoom in and follow them from the wider portions, you'll see the lines converge and reappear several times, so the lines you see at 1,800 and higher are really only artifacts generated by the camera's imaging system.

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

Sharpness & Detail
Pretty sharp images overall. Some visible edge enhancement artifacts, and some noticeable noise suppression as well. Still, good results.

The Pentax Optio A10 captures fairly sharp images overall, albeit with some visible edge enhancement artifacts on high-contrast subjects such as the crop above left. (Edge enhancement creates the illusion of sharpness by enhancing color and brightness changes 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 above right shows this, with darker areas of Marti's hair showing slightly limited detail. Still, fine detail is quite good, with individual strands of hair visible even in the shadows.

ISO & Noise Performance
Low to moderate noise at the normal sensitivity settings, higher noise and softer images at ISO 400.

The Pentax Optio A10 produced low to moderate noise at the lower ISO settings, and moderately high noise at ISO 200. At ISO 400, noise is higher, with more visible blurring in the fine details, though strands of hair are still quite distinct. At both ISO 200 and 400, the higher sensitivity results in a brighter overall exposure (a slight metering inaccuracy?), and the higher number of blue noise pixels shifts overall color toward a cooler cast.

Extremes: Sunlit and low light tests
High resolution with strong overall detail, but high contrast. Fair low-light performance, capable of capturing bright images under average city street lighting and slightly darker conditions.

Sunlight:
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.)

Under the harsh lighting of the test above, the Pentax Optio A10 produced high contrast with very hot highlights and deep shadows. The high contrast results in strong tonal variations in skin tone, with somewhat odd color shifts as a result. Using the camera's Low Contrast setting does even things out a little, but it also makes the overall exposure darker. Shadow detail is actually fairly good, though image noise decreases detail definition greatly. Though some areas look a little dark at +0.7 EV, I preferred it to the image at +1.0 EV, which had too many blown highlights for my preference. (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 Pentax Optio A10 captured usable images down to the 1/8 foot-candle light level (about 1/8 as bright as average city street lighting at night), though only at ISO 400. With each decrease in sensitivity, the maximum performance also crept back, so that at ISO 50, images are usable only to 1/2 foot-candle. I say "usable" here, because the overall images are still quite underexposed, with a magenta color cast from the Auto white balance setting. The camera's autofocus system was able to focus on the subject down to just above the 1/8 foot-candle light level unassisted. Do keep in mind though, that the longer shutter times required for shots like these 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.)

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
Dim exposures at the default exposure setting; the camera required average exposure compensation for flash exposures. Fairly good range though.

Flash coverage was uneven at wide angle, though much more uniform at telephoto. Indoors, under incandescent background lighting, the Pentax Optio A10's flash underexposed our subject a fair bit at its default setting, requiring a +1.0 EV exposure compensation adjustment to get bright results. Here, the highlights on the white shirt are a little hot, but the overall exposure at +0.7 EV was just a little too dim. The camera's Slow-Sync flash mode required a little less positive compensation at +0.7 EV, and overall coverage is more even. In both shots, color balance is a bit on the magenta side, with cool skin tones.

The Pentax Optio A10's flash was bright to about 11 feet at wide angle, before falling off in intensity. At telephoto, the flash remained bright to about 7 or 8 feet before gradually decreasing in intensity.

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.

Print Quality
Good print quality, somewhat understated color, good 13x19 inch prints. ISO 400 images are soft but usable at 8x10, look good at 5x7 inches and under.

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.)

With the Pentax A10, we found that it had enough resolution to make surprisingly sharp 13x19 inch prints. At high ISO, image noise produces visible blotchiness at ISO 400 and a print size of 8x10 inches, but viewed at arm's length (a typical viewing distance for prints of that size displayed on a wall or table), many consumers would likely find them acceptable. ISO 200 prints look fine at 8x10 inches, and ISO 400 ones make good 5x7s.

Color-wise, some prints from the A10 looked a little muted compared to other consumer cameras, others seemed brighter. Most consumers prefer highly saturated color, but others prefer a look that's closer to reality. The Pentax A10 would be a good choice for this latter group of users.