Pentax T30 Exposure

Saturation & Hue Accuracy
Generally good color and hue accuracy with slight oversaturation in blues and undersaturation in some yellows and greens.

Saturation. The Pentax Optio T30 oversaturates the strong blue tones, and undersaturates some yellow, orange, and green tones. Overall, saturation levels are more accurate than many competing models, but may appear a bit dull to some. 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 Pentax T30 does render skin tones slightly on the cool side in most cases, but results were still 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 Optio T30 did show a tendency toward cooler color balances, particularly outdoors. It pushed cyan toward blue, blue toward violet, and yellow toward green, making its color less accurate than that of many competing models. Overall color was still pleasing, but reds and greens definitely looked a bit dull when compared to other cameras' output. The other important part of color rendition is hue accuracy. Hue is "what color" the color is.

Exposure and White Balance

Indoors, incandescent lighting

Warm cast with Auto white balance setting, but good results from the Incandescent and Manual settings. Slightly above average positive exposure compensation required.

Color balance indoors under incandescent lighting is quite warm, with shades of orange and yellow in Auto white balance mode. Results with the Incandescent setting are pretty good with a slight magenta color cast. The Manual setting produced the most neutral and accurate result, with just a hint of a yellow cast. The Pentax T30 requires +1.0 EV exposure compensation boost to get a good exposure, a little higher than average for this shot. The slight yellow color cast in Manual mode flattens color somewhat, and the blue flowers in the bouquet are very dark and purplish. (Many digital cameras reproduce these flowers with a dark, purplish tint, so the T30's performance wasn't unusual.) 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 and exposure, though slightly high contrast.

Outdoors, the Pentax Optio T30 performs pretty well, with only sight overexposure in the outdoor far-field house shot. The Pentax T30 requires the average amount of positive exposure compensation on the portrait. Contrast is on the high side, but fortunately, there's a contrast adjustment to help compensate. The Pentax T30 captures good color outdoors, though slightly on the cool side. Overall, pretty good results here.

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Resolution
High resolution, 1,200 lines of strong detail.

Our laboratory resolution chart revealed sharp, distinct line patterns down to about 1,200 lines per picture height horizontally and vertically from the Pentax T30. Extinction of the pattern occurred between 1,800 and 1,900 lines. In the vertical crop above right, note the dead pixels that are revealed by the tight pattern of lines. This is not uncommon, but still worth noting. 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
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Sharpness & Detail
Sharp images overall, though visible edge-enhancement on high-contrast subjects. Moderate noise suppression limits detail in the shadows.

Sharpness. The Pentax Optio T30 captures images with slightly mottled detail. Some edge enhancement artifacts are visible on high-contrast subjects such as the crop above left, but it's not severe. 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 softening due to noise suppression, as the darker areas of Marti's hair show limited detail. 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, but very high noise and strong blurring at ISO 800 and above.

Noise levels are low to moderate at the Pentax OT30's lower sensitivity settings, with much higher noise above ISO 400. Noise pixels are bright at the higher settings, which throws off the color balance a bit. At ISO 400, while luminance noise is kept in check, we start to notice some blotchiness due to chroma noise, which only gets worse as ISO increases. At ISO 800, the grain pattern and chroma noise eliminates much of the finer details. At ISOs 1,600 and especially 3,200, bright noise pixels and strong chroma noise are very evident and give the image an almost veiled effect.

Extremes: Sunlit and low-light tests
High resolution with soft overall detail, and high contrast and limited shadow detail. Somewhat limited low-light performance.

Sunlight. The Pentax Optio T30 produced fairly high contrast with deep shadows under the harsh lighting of the test above. Detail is limited in the shadow areas, with some noise suppression visible. Though the shirt is nearly blown at +0.7 EV, I preferred it to the image at +0.3 EV, whose skin tones were under exposed. Depending on the photographer, you could lean one way or the other, but most Pentax T30 owners are going to want to just print an image, and the +0.7 image will produce a better print with little or no tweaking. (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.)

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.)

Low light: The Pentax T30 has somewhat limited low-light shooting capabilities. At ISO 64, only the image at one foot-candle level was sufficiently bright. At ISO 100, images were bright down to the 1/2 foot-candle level. At ISO 200, it took 1/4 foot-candle of illumination to get a bright image, and so on. It took ISO 800 to get a bright image at 1/16 fc, the lowest level we test, but the image was quite noisy. The camera's autofocus system worked fairly well, able to focus on the subject down to almost the 1/8 foot-candle light level unassisted, and well past the darkest light level we test with the AF assist lamp enabled.

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. Typical flash range at normal ISO settings.

Coverage. Flash coverage was uneven at wide angle. Though it was more uniform at telephoto, it was too weak to illuminate sufficiently. Indoors, under incandescent background lighting, the Pentax T30's flash underexposed our subject at its default setting, requiring a less-than-average +0.3 EV exposure compensation adjustment to get bright results. The Pentax T30 doesn't have a slow-sync flash mode, but it does have a "Soft" flash mode, which reduces the intensity of the flash. It's no surprise then that we had to use slightly more positive compensation at +0.7 EV, and that it didn't result in the usual warm cast from increased ambient light, as the shutter speed did not drop. In both shots, color balance is a bit on the magenta side.

ISO 100 Range. At ISO 100, the wide angle shot at nine feet was reasonably bright, decreasing in brightness from that point on. At full telephoto, the Pentax T30's flash power was inadequate even at six feet. A typical result for the class of camera.

Manufacturer Specified Flash Test. In the shots above, the Pentax T30 seems to perform exactly as Pentax says it will at both wide angle and telephoto, producing a good exposure, at the rated distance with its ISO set to Auto. It did however have to boost ISO to 400 respectively to do so, resulting in added noise.

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.

Print Quality
Good print quality, slightly undersaturated color, good 11x14-inch prints. ISO 400 images are soft but usable at 11x14, ISO 800 shots are better at 5x7. ISO 1,600 shots are still good at 5x7.

The Pentax Optio T30 had enough resolution to make decent 11x14 inch prints, with the exception of the extreme softness in the upper right and lower left corner. ISO 400 images are okay at 11x14, but are better kept to 8x10. ISO 800 images are passable at 8x10, but really better at 5x7. ISO 1,600 images were surprisingly usable at 5x7, but ISO 3,200 images were still a little too mottled at 4x6 to be acceptable.

Color fades a little as you move up the ISO ladder, but not badly.

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 iP5200 here in the office. (See the Canon PIXMA Pro 9000 review for details on that model.)