Colour Chart Comparison
Using the test charts in our review database we can compare the Optio 430 to three other digital cameras: Pentax Optio 330, Canon PowerShot S40 and Olympus C-40Z (D-40Z).
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.
|Pentax Optio 430||Canon PowerShot S40|
|Pentax Optio 330||Olympus C-40Z|
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 you can see the Optio 430 exposed slightly brighter than the 330 but overall colour balance was virtually identical. Both cameras produced a 'cool' white balance (a mild blue cast) and yet suffered to produce strong greens or dark blues.
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.
|Horizontal resolution||Vertical resolution||5 degree diagonal res.|
|Pentax Optio 430|
|Canon PowerShot S40|
|Olympus C-40Z (D-40Z)|
|Pentax Optio 330|
Measurable findings (three measurements taken for each camera):
|Camera||Measurement||Absolute Res.||Extinction Res.|
|Pentax Optio 430||Horiz LPH||1100||*1250|
|5° Diagonal LPH||900||n/a|
|Canon PowerShot S40||Horiz LPH||1250||*1400|
|5° Diagonal LPH||1000||n/a|
|Olympus C-40Z||Horiz LPH||*1200||*1350|
|5° Diagonal LPH||1000||n/a|
|Pentax Optio 330||Horiz LPH||900||*1100|
|5° Diagonal LPH||800||n/a|
* Moiré is visible
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.
Again it's not good news for the four megapixel Optio. It's clear that there is either a problem with the lens, CCD, image processing or all three. The Optio 430 doesn't deliver what we'd expect of a four megapixel and as you can see (visually and numerically) it's a fair amount behind the Canon S40 and Olympus C-40Z. Indeed, the "gain" from the three megapixel Optio 330 is minimal.