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| Canon Pro90 IS | Sony DSC-F505V |
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| Canon G1 | Nikon Coolpix 990 |
As we'd expect the Pro90 and G1 charts look almost identical, all the cameras here are of the newer generation consumer digital cameras which have little problem properly exposing and capturing relatively accurate colours.
We're only measuring colour below. RGB values below were taken from a VGA reduced image (to average colours and eliminate JPEG artifacts) using the Eyedropper tool in Photoshop with a 5 by 5 Average Sample Size.
| Canon PowerShot
Pro90 IS |
Canon PowerShot
G1 |
Sony DSC-F505V |
Nikon Coolpix 990 |
|
| Patch White | 212,207,207 | 214,208,208 | 178,182,182 | 201,201,201 |
| Middle Gray | 105,102,105 | 97,96,102 | 79,81,87 | 104,104,104 |
| Patch Red | 187,35,52 | 186,33,53 | 187,15,32 | 223,52,58 |
| Patch Green | 41,143,73 | 26,149,73 |
3,135,41 |
5,149,63 |
| Patch Blue | 47,50,109 | 55,49,117 | 40,25,123 | 60,50,112 |
Virtually identical results between the Pro90 and G1, though we still ee the "purists colours" from Sony's DSC-F505V.
Resolution Comparison
Shots here are of the PIMA/ISO 12233 standard resolution test chart (more available for comparison in our comparison database). Studio light, cameras set to auto, Exposure compensation +0.7 EV for all cameras. How to read the charts: All values are 1/100 th lines/picture height/width. So the "10" value equates to 1000.
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| Canon Powershot Pro90 IS (2.6 mp) | |
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| Sony DSC-F505V (2.6 mp) | |
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| Canon G1 (3.1 mp) | |
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| Nikon Coolpix 990 (3.1 mp) | |
Measurable findings (three measurements taken for each camera):
| Camera | Measurement | Absolute Res. | Extinction Res. |
| Canon PowerShot Pro90 IS |
Horiz LPH | 900 | 1200 |
| Vert LPH | 900 | 1150 | |
| 5o Diagonal LPH | 900 | n/a | |
| Sony DSC-F505V | Horiz LPH | 950 | 1300 |
| Vert LPH | 950 | 1250 | |
| 5o Diagonal | 900 | n/a | |
| Canon PowerShot G1 |
Horiz LPH | 950 | 1300 |
| Vert LPH | 950 | 1400 | |
| 5o Diagonal LPH | 900 | n/a | |
| Nikon Coolpix 990 |
Horiz LPH | 900 | 1300 |
| Vert LPH | 900 | 1400 | |
| 5o Diagonal LPH | 900 | n/a |
Definition of terms:
| LPH | Lines per Picture Height (to allow for different aspect ratios the measurement is the same for horizontal and vertical) |
| 5o Diagonal | Lines set at 5o diagonal |
| Absolute Resolution | Still defined detail (below Nyquist frequency*) |
| Extinction Resolution | Detail beyond camera's definition (becomes a solid gray alias) |
| n/a | Not Available (above the capability of the test chart) |
| n/v | Not Visible (not visible on test results) |
* Nyquist frequency defined as the highest spatial frequency where the CCD can still faithfully record
image detail. Beyond the Nyquist frequency aliasing occurs.
The Pro90 puts in a relatively good performance, despite it's lower resolution it manages to hang on to at least as much resolution as the Coolpix 990, not quite as much as it's brother the G1 and still not as sharp as the F505V which remains our king of resolution castle.
Red Channel Noise
When we first started reviewing the new batch of 3 megapixel digital cameras we noticed visible noise on flat blue areas, this turned out to be in the red channel and was thus dubbed "Red Channel Noise", we can see this as information in the red channel where there shouldn't be any. The samples below are of 40 x 40 blocks cropped from the colour comparison charts above of the Blue and Cyan patches, each block is then broken down into it's red, green and blue channels and reflected as such directly beneath.
Note: The Pro90 & G1 samples were taken at ISO 50, the F505V & Coolpix 990 at ISO 100.
As we'd expect Canon's ISO 50 produces clean blues with very little noise matched by Sony's F505V which also manages to produce a purer colour.
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