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Compared to... (contd.)

Here we will use our standard color and resolution charts to compare C-50 Zoom to the Pentax Optio 550, Canon PowerShot S50 and Nikon Coolpix 5000.

Colour Chart Comparison

Colour charts are shot in daylight, Auto White Balance, EV compensation +0.3 (all cameras), measured light ~10 EV. This test is also dependent on the accuracy of the camera's auto white balance, the colour charts are shot in daylight but some camera's white balance is better than others. All cameras are given 20 seconds to "settle" before the shot is taken.

Olympus C-50 Zoom Pentax Optio 550
Canon PowerShot S50 Nikon Coolpix 5000

In the table below we're only measuring colour. The RGB values were measured from a VGA reduced image (to average colors, remove noise and eliminate JPEG artifacts) using the Eyedropper tool in Photoshop with a 5 by 5 Average Sample Size.

Patch Olympus
C-50 Zoom
Pentax
Optio 550
Canon
PowerShot S50

Nikon
Coolpix 5000

Black 37,31,40 26,25,25 33,34,35 19,20,19
Middle Gray 105,105,116 95,92,93 96,100,103 91,91,91
White 218,221,227 217,211,210 208,210,211 209,209,205
Magenta 201,10,127 210,18,99 199,44,121 219,37,93
Red 199,9,48 196,14,26 197,37,46 207,26,23
Yellow 215,204,20 204,196,45 203,193,23 212,189,47
Green 18,142,77 19,149,74 9,136,72 0,130,68
Cyan 8,149,202 23,178,227 6,144,214 1,153,200
Blue 53,35,121 45,28,106 29,41,109 33,44,98

The C-50 Zoom's white balance did seem to consistently produce a cooler (more blue) white balance than the other cameras. This can be seen by the high value of the blue channel above (most noticeable in the black, gray and white patches). The C-50 Zoom's color balance is probably closest to Canon's PowerShot S50.

Resolution Comparison

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. So a value of 8 equates to 800 lines per picture height.

Studio light, cameras set to auto, all settings factory default. Exposure compensation +0.7 EV for all cameras (to compensate for the white background). Click on the camera name below the crops to download the full resolution chart (large JPEG's).

Horizontal resolution Vertical resolution 5 degree diagonal res.
Olympus C-50 Zoom (2,152 KB)
Pentax Optio 550 (2,254 KB)
Canon PowerShot S50 (2,011 KB)
Nikon Coolpix 5000 (1,609 KB)

Measurable findings (three measurements taken for each camera)

Camera Measurement Absolute Res. Extinction Res.
Olympus C-50 Zoom Horizontal LPH * 1425  * 1650 
Vertical LPH * 1300  * 1650 
5° Diagonal LPH + 1000  n/a 
Pentax Optio 550 Horizontal LPH 1350  1500 
Vertical LPH 1250  1450 
5° Diagonal LPH + 1000  n/a 
Canon PowerShot S50 Horizontal LPH 1425  1650 
Vertical LPH 1300  1600 
5° Diagonal LPH # + 1000  n/a 
Nikon Coolpix 5000 Horizontal LPH * 1350  * 1500 
Vertical LPH * 1200  1500 
5° Diagonal LPH + 1000  n/a 

* Moiré is visible, + Chart maximum, # Jagged diagonals

Definition of terms

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 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 C-50 Zoom surprised us in the resolution test because here it produced as much resolution as the Canon PowerShot S50 and more than the Pentax Optio 550. This surprise due to its performance on the previous page, our side-by-side comparison. We can only conclude that the C-50 Zoom lost some of its ability to resolve detail in that test because of increased image noise. Overall the C-50 Zoom produced higher resolution than we would expect from a compact five megapixel digital camera (although it's worth noting the moiré at the limit).

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