Compared to... (contd.)

Now we'll use the data in our review database to compare the S45's color and resolution to three other four megapixel digital cameras: the Minolta DiMAGE F100, Sony DSC-P9, and Olympus C-40Z.

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.

Canon PowerShot S45	Minolta DiMAGE F100
Sony DSC-P9	Olympus C-40Z

A good balanced response, notably good blue, green and yellow compared to some of the other cameras here. Color is vivid without being over-saturated, and you can always control this with the camera's Effect menu.

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

As noted in my F100 review color response from these four cameras is remarkably similar, most of the manufacturers seem to be getting closer to an optimum appearance for color from compact digital cameras. It's worth noting that the S45 manages to produce blues and yellows more accurately with less channel crossover than the others.

Resolution Chart 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 1/100^th 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.

Horizontal resolution	Vertical resolution	5 degree diagonal res.
Canon PowerShot S45
Minolta DiMAGE F100
Sony DSC-P9
Olympus C-40Z

Measurable findings (three measurements taken for each camera):

Definition of terms:

The S45 managed to deliver a remarkable amount of resolution considering its compact lens system. Better still it does so without any noticeable moiré or strong sharpening artifacts. A very good performance for this class of cameras. The only thing worth noting may be the slight stepping visible in the 5° resolution lines.