Resolution Chart Comparison

Comparison cameras:

  • Sony Cyber-shot DSC-W7 (7 MP, 3x zoom)
  • Canon PowerShot SD500 (7 MP, 3x zoom)
  • Nikon Coolpix 7900 (7 MP, 3x zoom)
  • Casio Exilim EX-Z750 (7 MP, 3x zoom)

Shots here are of the PIMA/ISO 12233 standard resolution test chart (more of which are available in our comparison database). This resolution chart allows us to measure the actual performance of the lens and sensor system. It measures the ability of the camera to resolve lines at gradually higher resolutions and enables us to provide a definitive value for comparison purposes. Values on the chart are 1/100th lines per picture height. Thus a value of 15 equates to 1500 lines per picture height.

Studio light, cameras set to auto, settings all factory default. If possible aperture was selected for optimum sharpness. Exposure compensation +0.7 EV to +1.3 EV.

Sony Cyber-shot DSC-W7 (2,816 KB; 7 MP) Nikon Coolpix 7900 (2,348 KB; 7 MP)
Canon PowerShot SD500 (2,415 KB; 7 MP) Casio Exilim EX-Z750 (3,991 KB; 7 MP)

Resolution Chart crops

Sony Cyber-shot DSC-W7 Nikon Coolpix 7900
Canon PowerShot SD500 Casio Exilim EX-Z750
Sony Cyber-shot DSC-W7 Nikon Coolpix 7900
Canon PowerShot SD500 Casio Exilim EX-Z750

Measurable findings

Camera Measurement
Sony DSC-W7 Horizontal LPH 1550 1900
Vertical LPH 1600 1900
5° Diagonal LPH + 1000 n/a 
Canon PowerShot SD500 Horiz LPH 1600 1850
Vert LPH * 1700 +* 2000
5° Diagonal LPH + 1000 n/a 
Nikon Coolpix 7900 Horizontal LPH 1500 1750
Vertical LPH 1500 1750
5° Diagonal LPH + 1000 n/a 
Casio EX-Z750 Horizontal LPH 1650 +* 2000
Vertical LPH 1600 *1900
5° Diagonal LPH + 1000 n/a 

* 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)
5° Diagonal Lines set at 5° diagonal
Absolute res. 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 res. Detail beyond camera's definition (becomes aliased)
n/a Not Available (above the capability of the test chart)
n/v Not Visible (not visible on test results)

The W7 is capturing lots of detail (the resolution is amongst the highest in its class), and there's very little moiré. On the downside, close examination of the results shows the W7 images to be a little soft, with visible sharpening halos, but there's no denying that plenty of detail is being captured. There is a measurable, though not extreme, reduction in resolution at F8 as a result of diffraction effects.