Resolution Chart Comparison (JPEG)

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.

Nikon D300s (3.4 MB; 12 MP) Canon EOS 7D (4.8MB, 18 MP)
Pentax K7 (8.6 MB, 14.5 MP) Canon EOS 50D (4.1 MB, 15.1 MP)

Nikon D300S Canon EOS 7D
Pentax K-7 Canon EOS 50D

Nikon D300S Canon EOS 7D
Pentax K-7 Canon EOS 50D

Nikon D300S Canon EOS 7D
Pentax K7 Canon EOS 50D

Measurable results

Camera Measurement
Nikon D300S Horizontal LPH 2200  2500 
Vertical LPH 2100  2600 
Canon EOS 7D Horizontal LPH 2500  * 3100 
Vertical LPH 2450  * 3050 
Pentax K-7 Horizontal LPH 2300  * 2700 
Vertical LPH 2250  * 2650 
Canon EOS 50D Horizontal LPH 2250  2700 
Vertical LPH 2200  2700 

* 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)

The soft JPEGs we've already seen in this review do nothing to help the D300S in this test - any resolution disadvantage of its lower pixel count is exacerbated by its rather smooth output. As a result, it is out-performed by both Canons. Similarly soft JPEGs from the Pentax mean the Nikon doesn't look too outclassed.