Resolution and Noise of K-7 vs. K20D

Full size of test shot All shots WB at 3900 Kelvin (warmer than daylight, it was indirect evening sun). All shots aperture at f/4.0 and underexposed at will (roughly 2/3 and 1-2/3 stops) This shot Pentax K-7 at 1/30s

ISO 100 Upper row: 1/30s, lower row: 1/60s Left side: K-7, right side: K20D 100% crops

ISO 200 Upper row: 1/60s, lower row: 1/125s Left side: K-7, right side: K20D 100% crops

ISO 400 Upper row: 1/125s, lower row: 1/250s Left side: K-7, right side: K20D 100% crops Upper left: tripod still vibrating Lower left: must have been a shadow outside, shot in indirect daylight...

ISO 800 Upper row: 1/250s, lower row: 1/500s Left side: K-7, right side: K20D 100% crops

ISO 1600 Upper row: 1/500s, lower row: 1/1000s Left side: K-7, right side: K20D 100% crops

ISO 3200 Upper row: 1/1000s, lower row: 1/2000s Left side: K-7, right side: K20D 100% crops

ISO 6400 Upper row: 1/2000s, lower row: 1/4000s Left side: K-7, right side: K20D 100% crops

Synthetic resolution test shot. Pentax K-7 + DA 70mm Ltd. Full size.

Synthetic resolution test shot. Pentax K20D + DA 70mm Ltd. Full size.

Synthetic resolution test shot. Pentax K-7 + Zeiss 50mm. Full size.

Synthetic resolution test shot. Pentax K-7 + Zeiss 50mm ("premature series"). Full size.

Sample resolution test shot. Pentax K-7 + DA 70mm Ltd. Full size as shot.

Sample resolution test shot. Pentax K20D + DA 70mm Ltd. Full size as shot.

Sample resolution test shot. Pentax K-7 + Zeiss 50mm Full size as shot.

Sample resolution test shot. Pentax K-7 + Zeiss 50mm ("premature series"). Full size as shot.

Synthetic superresolution test shot crop. Pentax K-7 + DA 70mm Ltd. 200% crop (of inner part, rotated). The K-7's Nyquist limit is at chart number "6.7".

Synthetic superresolution test shot crop. Pentax K20D + DA 70mm Ltd. 200% crop (of inner part, rotated). The K20D's Nyquist limit is at chart number "6.7".

Synthetic superresolution test shot crop. Pentax K-7 + Zeiss 50mm. 200% crop (of inner part, rotated). The K-7's Nyquist limit is at chart number "6.6".

Synthetic superresolution test shot crop. Pentax K-7 + Zeiss 50mm ("premature series"). 200% crop (of inner part, rotated). The K-7's Nyquist limit is at chart number "7.0".

Final analysis: synthetic superresolution test shot crop comparison. The two bottom rows are produced under identical conditions. The two upper rows are for accompanying discussion of K-7 results. The left row are crops from the superresolution crops, the right row are 200% crops from the samples as shot (levels adjusted). The "premature series" are shots from the noise test with incomplete control over lightning and focus.

The same image. Left part is a 100% crop as exported from Lightroom with default settings. The inset to the right is a shot from the rear screen of the K-7, in 19x magnified view, scaled to the same size.

Snippet from crop shown above: Synthetic superresolution test shot crop. Pentax K-7 + DA 70mm Ltd. 200% crop (of inner part, rotated). The K-7's Nyquist limit is at chart number "6.7".