Shots here are of our 'version two' resolution chart which provides for measurement of resolution up to 4000 LPH (Lines Per Picture Height). A value of 20 equates to 2000 lines per picture height. For each camera the relevant prime lens was used. The chart is shot at a full range of apertures and the sharpest image selected. Studio light, cameras set to aperture priority (optimum aperture selected), image parameters default. Exposure compensation set to deliver approximately 80% luminance of white area.
For a (more) level playing field we also convert our resolution tests using Adobe Camera RAW. Because Adobe Camera RAW applies different levels of sharpening to different cameras (this confirmed) we use the following workflow for these conversions:
Load RAW file into Adobe Camera RAW (Auto mode disabled)
Set Sharpness to 0 (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
Shooting in RAW and using Adobe ACR to process the images increases the measured resolution on all four cameras, although as expected, the more densely populated sensor of the Canon EOS-1D Mark IV resolved the highest detail when presented with our test chart. To any practical extent, the D3S gives identical resolution, again, to its predecessor the D3, and to the DX format D300S.