Camera Test: Pentax K20D

	Click photo for a gallery of images taken by the Pentax K20D.

The 10.2MP Pentax K10D was a DSLR bargain in 2007 with its nearly pro body, excellent image quality, fast AF, image stabilization, and a price of only $920 (body only) when launched. It's still a steal at $700 (street). But if you want a camera with higher resolution, larger LCD, live view, and other enhancements, check out the new 14.6MP Pentax K20D ($1,299, estimated street).

At first, the K20D seems to be a twin to the K10D. Pentax kept what was outstanding in the K10D and improved it in all the right places, so the K20D is more of an upgrade than a new design. We got our hands on one of the first production units, and after running it through the Pop Photo Lab and field tests, found five reasons why this camera promises to be a big hit.

Image quality

This camera captures the most detail in its price class at ISOs below 1600. Incorporating the first Samsung-produced APS-C-sized CMOS sensor, the K20D represents a shift from the Sony CCDs found in previous Pentax DSLRs, and a further strengthening of Samsung's partnership with Pentax. By the time you read this, Samsung will have released its own camera with specs similar to the K20D.

According to Pentax, the new sensor captures 14.6 megapixels (effective) in 4672x3120-pixel files, with up to 12 bits per color in RAW. In addition, the pixel design expands the light-gathering photo diode to about the same area as competitive 12-megapixel CCD sensors. This gives the K20D the potential for higher resolution than the K10D, with light sensitivity similar to more expensive 12MP DSLRs such as the Nikon D300 ($1,800, street, body only) or Sony Alpha 700 ($1,350, street, body only). With increased sensitivity and noise reduction, Pentax boosted the normal ISO range up to ISO 3200, and the expanded range as high as ISO 6400.

The camera's PRIME image processing system can store RAW data from the sensor as JPEGs, PEF RAW (Pentax), RAW DNG (Adobe standard), or JPEG + RAW files. Or it can channel images to a live preview on the 2.7-inch LCD. And thanks to the lower power drain of a CMOS sensor, the rechargeable lithium ion battery (same as in the K10D) earns a CIPA rating of 720 shots (half with flash), despite more intensive processing (though it doesn't include IS battery drain).

Impressive specs? Yes, but the K20D produced impressive results in the Pop Photo Lab, especially in resolution and detail at most ISOs. At 2350 lines of resolution at ISO 100-400, the K20D delivers slightly higher resolution than the Nikon D300. Then resolution drops by 5-10 percent as you crank up noise reduction at higher ISOs. Nonetheless, at ISO 6400, the resolution was still Excellent at 2100 lines.

In noise or color accuracy tests, however, the K20D doesn't outclass the Nikon D300, especially at ISO 3200 and 6400, or when shooting JPEGs at any ISO. At ISO 1600 it earns a Moderate noise rating, but thanks to its high resolution and Excellent color accuracy at that ISO, it still qualifies for an Excellent image quality rating from ISO 100 to ISO 1600 when shooting RAW files and converting them to TIFF. At ISO 3200, noise levels are Unacceptable, and downright irritating at ISO 6400.

JPEGs earn just Extremely High ratings for image quality even at lower ISOs due to their less-than-stellar color accuracy, which comes in only at a High rating (11 average Delta E). That's two levels down from the Excellent color accuracy (7.98 Delta E) we found when making TIFFs with the supplied Pentax RAW converter (from SilkyPix, the same folks providing Panasonic's RAW converter). JPEG resolution is about 5 percent lower than RAW, but noise levels are similar even when converting RAW files in-camera and saving them as JPEGs (a useful feature).

The K20D turns out impressive images at ISO 100-1600, and proves that Samsung's new, larger DSLR sensors can stand up to the chips made by Canon, Sony, and others.