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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
Nikon D3000 (2.8MB, 10.2 MP) Canon EOS 1000D (2.2 MB, 10.1 MP)
Sony Alpha 230 (2.4 MB; 10.2 MP) Pentax K2000 (2.7 MB, 10.2 MP)

Nikon D3000 Canon EOS 1000D
Sony Alpha 230 Pentax K2000

Nikon D3000 Canon EOS 1000D
Sony Alpha 230 Pentax K2000

Nikon D3000 Canon EOS 1000D
Sony Alpha 230 Pentax K2000

Measurable results

Camera Measurement
Absolute
resolution
Extinction
resolution
Nikon D3000 Horizontal LPH 2000  3200 
Vertical LPH *1900  * 2250 
Canon EOS 1000D Horizontal LPH *2150  * 2450 
Vertical LPH 1950  2150 
Sony Alpha 230 Horizontal LPH *2000  *2250 
Vertical LPH *2000  * 2200 
Pentax K2000 Horizontal LPH *1950  * 2200 
Vertical LPH *2050  * 2300 

* 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 aliased)

Again, very similar resolution here from the Nikon D3000 and Canon EOS 1000D. Both cease to be able to accurately resolve lines in both the vertical and horizontal axes at exactly the same point, although Adobe Camera RAW has done a better job with the Canon raw file, which does not display the same unpleasant demosaicing artifacts that can be seen in the Nikon image.

Interestingly, compared to its JPEG output, the Sony Alpha 230's (simultaneously captured) raw file actually appears to show slightly less detail. To make sure this wasn't a problem with ACR's demoasicing algorithm, we converted the A230's raw file in three different raw converters, including Sony's bundled Image Data Converter, but the absolute and extinction resolution points were the same in each conversion. We've noticed the same discrepancy with other Sony Alpha DSLRs, and it seems that Sony's JPEG engine is better at 'guessing' how detail should look at frequencies beyond Nyquist than it's raw converter (or anyone else's for that matter).

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