Pentax T30 Optics

Zoom
Fair performance with the 3x optically stabilized zoom lens. Digital zoom is soft at maximum setting.

The Pentax Optio T30's optical zoom covers the equivalent of 37.5-112.5mm, which is a typical focal range for an ultra-compact model. Overall performance is fair, with good detail and sharpness at wide angle, however there is noticeable chromatic aberration in the corners and the right-hand side is quite soft, especially the upper right corner. At telephoto, performance is quite good, with negligible chromatic aberration and far less softening in the corners. The Pentax T30's 4x digital zoom performs reasonably well, but one must remember the a 4x digital zoom from a 7.1 megapixel camera is interpolated from less than 450k pixels of image data cropped from the center, so we can't expect results to be nearly as sharp or detailed as optical zoom.

Macro
A large, below average macro area, but with good detail and sharpness. The flash had trouble throttling down, and produced an uneven exposure.

The Pentax Optio T30's macro setting captures a very large minimum area of 6.37 x 4.77 inches (162 x 121 millimeters). While the macro area is far below average for digicams these these days, details are good with crisp definition almost to the edges of the frame (though the right side exhibits more softness than the left, again). Most cameras have some softening in the corners in macro mode. Even at the relatively long minimum macro focal distance, the flash had a hard time throttling down, and couldn't cover the frame evenly. (Plan on using external lighting for any macro shots with the T30.)

Distortion
High barrel distortion at wide angle, low at telephoto.

The Pentax Optio T30's 1.0% barrel distortion at wide angle is higher than average among the cameras we've tested, and noticeable in some of its images. We're normally used to seeing pincushion distortion at telephoto, but the T30's lens exhibits about 0.3% barrel distortion at long end, which is not very noticeable in images. Distortion is the tendency for the lens to bend straight lines outward (like a barrel -- usually at wide angle) or inward (like a pincushion -- usually at telephoto).

Chromatic aberration
Moderately high, with noticeable effect on images at edges in some wide angle shots.

Chromatic aberration is moderate to high at wide angle, showing about 5-6 pixels of bright coloration on either side of the target lines, with corner softness increasing the effect. At full telephoto, the Pentax T30's chromatic aberration is quite low, and not as bright. Overall, the effect is noticeable in a few of our wide angle test shots. Note: This distortion is visible as a very slight colored fringe around the objects at the edges of the field of view on the resolution target.

Corner Sharpness
Excessive blurring in the upper right corners of the frame at both wide angle and telephoto.

The Pentax Optio T30 produces very soft results in the right corners of the frame at full wide angle, with the top right corner being the worst case. At full telephoto, results improve a bit, but the upper right corner is still very soft. The effect is quite noticeable in some of our test images.

Coverage
Good accuracy from the LCD monitor. The Pentax T30 does not have an optical viewfinder.

The Pentax Optio T30's LCD viewfinder was quite accurate, showing about 102% coverage at wide angle, and about 101% coverage at telephoto.