For a (more) level playing field for comparison we also shot our studio scene in RAW mode with each camera and converted it using Adobe Camera RAW. Because Adobe Camera RAW applies different levels of sharpening to different cameras (this confirmed) we had to use the following workflow for these conversions:
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). Camera settings as per previous pages.
In both cases we used our standard workflow (sharpening turned off in the raw converter and applied at an equal level in Photoshop before saving as JPEG):
Load RAW file into Adobe Camera RAW (Auto mode disabled)
/ Capture One
Set Sharpness to zero (all other settings default)
Open file to Photoshop
Apply a Unsharp mask: 80%, Radius 1.0, Threshold 0
Save as a TIFF (for cropping) and as a JPEG quality 11 for download
Sony DSLR-A550 vs Pentax K-7
Camera settings as before
Sony DSLR A550
8.5 MB JPEG (4592 x 3056)
5.1MB JPEG (4672 x 3104)
The Pentax gains more from a switch to raw/ACR, but the differences aren't great, and with careful sharpening you'll get visually similar results. Ultimately, however, as the studio, real world and resolution chart tests clearly show, the Alpha 550 isn't capturing quite the level of detail we'd expect from such a pixel-packed sensor.