Compared to... Pentax K-7

The Pentax K-7 is, to be fair, in a totally different league to the Alpha 550; being closer to 'semi pro' thanks to its weather-sealed magnesium alloy body and high-spec viewfinder - and is commensurately more expensive. But in terms of headline features the K-7 and Alpha 550 are surprisingly close, with the main difference being, once again, the Alpha's lack of movie mode, balanced by a higher continuous shooting rate, tilting screen and its unique live view mode. Sure, the potential A550 customer might not be considering a K-7 too, but we were interested to see how the two compared in the studio.

Studio scene comparison (JPEG)

This is our standard studio scene comparison shot taken from exactly the same tripod position. Lighting: daylight simulation, >98% CRI. Crops are 100%. Ambient temperature was approximately 22°C (~72°F).

Sony DSLR-A550 vs Pentax K-7

Camera settings:

• Sony Alpha 550: Sony 50 mm F1.4 lens, Aperture Priority, ISO 200 JPEG Large/Fine,
  Manual WB, Default Parameters (Standard, DRO auto), Self-Timer
  
  
• Pentax K-7: Pentax 50 mm F1.4 lens, Aperture Priority, ISO 100
  JPEG Large/Fine, Manual WB, Default Parameters (Bright CI), Self-Timer (auto MLU)

Sony DSLR-A550	Pentax K-7
4.1 MB JPEG (4592 x 3056)	6.3MB JPEG (4672 x 3104)

With an almost identical pixel count the A550 and K-7 are, unsurprisingly, producing superficially very similar JPEG output, though once again the Sony's slight softness does it no favors in a side-by-side comparison at 100%. In normal circumstances the only difference you're likely to note is the A550's slightly higher default color saturation. The Alpha 550 certainly isn't put to shame by the more expensive Pentax flagship.