Resolution Chart Comparison (RAW)

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
Canon EOS-1D Mark IV (3.4 MB, 16.0 MP) Nikon D3S (3.5 MB; 12.1 MP)
Canon EOS-1D Mark III (2.0 MB, 10.1 MP) Canon EOS 7D (4.0 MB, 17.9 MP)

Canon EOS-1D Mark IV Nikon D3S
Canon EOS-1D Mark III Canon EOS 7D

Canon EOS-1D Mark IV Nikon D3S
Canon EOS-1D Mark III Canon EOS 7D

Canon EOS-1D Mark IV Nikon D3S
Canon EOS-1D Mark III Canon EOS 7D

Measurable results

Camera Measurement
Canon EOS-1D Mark IV Horizontal LPH *2500  * 3600 
Vertical LPH *2500  * 3400 
Nikon D3S Horizontal LPH 2300  3300 
Vertical LPH 2250  3100 
Canon EOS-1D Mark III Horizontal LPH *2200  *2800 
Vertical LPH 2150  *2800 
Canon EOS 7D Horizontal LPH 2500  * 3800 
Vertical LPH 2500  * 3900 

* Moiré is visible
+ Chart maximum
LPH Lines per Picture Height (to allow for different aspect ratios the measurement is the same for horizontal and vertical)
Absolute resolution Point at which all lines of a resolution bar are still visible and defined, beyond this resolution loss of detail occurs (below Nyquist frequency).
Extinction resolution Detail beyond camera's definition (becomes alias ed)

There's no a lot more to say about resolution from the RAW files, given how similar the JPEG output results were to one-another. We're still not quite seeing the theoretical 26% resolution improvement over the Mark III but the Mark IV is clearly capturing an awful lot of detail. And, on a camera like this, that extra detail means great ability to crop.