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.
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| Sony Cyber-shot DSC-W7 (2,816 KB; 7 MP) | Nikon Coolpix 7900 (2,348 KB; 7 MP) |
|---|---|
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| Canon PowerShot SD500 (2,415 KB; 7 MP) | Casio Exilim EX-Z750 (3,991 KB; 7 MP) |
Resolution Chart crops
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| Sony Cyber-shot DSC-W7 | Nikon Coolpix 7900 |
|---|---|
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| Canon PowerShot SD500 | Casio Exilim EX-Z750 |
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| Sony Cyber-shot DSC-W7 | Nikon Coolpix 7900 |
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| Canon PowerShot SD500 | Casio Exilim EX-Z750 |
Measurable findings
| Camera | Measurement | Absolute resolution |
Extinction resolution |
|---|---|---|---|
| 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.
