Pentax K-30 vs Sony SLT Alpha 55 — Which Is Better?

The Pentax K-30 and the Sony SLT Alpha 55 are both APS-C DSLRs, but they suit different shooters. The 2012 K-30 is a weather-sealed body built for outdoor work, while the 2010 Alpha 55 pairs an electronic viewfinder with a lighter, more compact build.

The Alpha 55 is the lighter camera to carry, at 500 g against 650 g for the K-30. It is also smaller at 124 x 92 x 85 mm, compared with 130 x 97 x 71 mm for the Pentax.

The Alpha 55 is the stronger choice for action sequences, capturing 10 frames per second against 6 fps from the K-30, with 15 autofocus points to the Pentax's 11. The K-30 answers with a shorter maximum exposure of 1/6000 second, useful for wide apertures in bright light, against 1/4000 on the Sony.

Their sensors are a near-match for detail, at 16.3 and 16.2 megapixels, and both pair an APS-C CMOS sensor with in-body stabilisation and a standard ISO range of 100 to 12800. The viewfinders split them: the K-30 has an optical pentaprism, while the Alpha 55's electronic viewfinder shows 1,150,000 dots. Lenses are brand-specific, with the K-30 on the Pentax KAF mount and the Alpha 55 on Sony Alpha DT.

For casual handheld clips the two are evenly equipped, because Full HD is the maximum recording resolution on both and each has a maximum video frame rate of 30 fps. The K-30 is the better tool for interval work, since it offers built-in timelapse and the Alpha 55 does not. File handling differs as well: the Pentax writes MPEG-4, while the Sony offers AVCHD and MP4.

Weather sealing gives the K-30 the advantage for shooting in rain or dust, a protection the Alpha 55 does not offer. The Sony counters with a flip screen for waist-level and overhead framing, plus built-in GPS that tags each photo's location for travel cataloguing. The rear screens match on these specifications: both are 3-inch, 921,000-dot LCDs with live view, and both cameras include a built-in flash.

The battery ratings slightly favour the K-30, whose D-LI109 pack is rated for 410 shots against 380 shots for the Alpha 55's NP-FW50. Storage overlaps on the SD family, with both taking SD, SDHC and SDXC cards in a single slot, and the Sony also accepts Memory Stick Pro Duo and Pro-HG Duo media. Neither body charges over USB, so both depend on an external charger.