Pentax Optio 330 Review: 10. Compared to...: Digital Photography Review

Compared to...

Colour Chart Comparison

Using the test charts in our review database we can compare the Optio 330 to three other 3 megapixel compact digital cameras: Kycoera Finecam S3, Sony DSC-P5 and Nikon Coolpix 885.

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 330	Kyocera Finecam S3

Sony DSC-P5	Nikon Coolpix 885

Here you can clearly see the Optio 330's underexposure and 'heavy contrast'. Otherwise colour balance is very good with strong and vivid yet accurate colours.

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.

Patch	Pentax Optio 330	Kyocera Finecam S3	Sony DSC-P5	Nikon Coolpix 885
Black	10,13,15	30,29,26	20,21,22	34,34,34
Black
Middle Gray	71,80,86	140,140,134	93,98,99	102,102,102
Middle Gray
White	179,181,187	235,234,219	197,202,198	197,197,197
White
Magenta	174,1,89	233,81,154	177,27,124	226,41,94
Magenta
Red	176,0,21	232,74,49	172,18,36	213,29,25
Red
Yellow	188,174,30	234,234,42	194,188,30	180,188,53
Yellow
Green	10,119,63	44,188,80	28,142,59	0,151,91
Green
Cyan	0,133,187	33,207,222	29,162,208	22,174,220
Cyan
Blue	21,22,92	73,60,154	40,28,122	61,51,108
Blue

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 1/100^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.

Pentax Optio 330

Kyocera Finecam S3

Sony DSC-P5

Nikon Coolpix 885

Measurable findings (three measurements taken for each camera):

Camera	Measurement	Absolute Res.	Extinction Res.
Pentax Optio 330	Horiz LPH	900	* 1100
	Vert LPH	900	* 1100
	5^o Diagonal LPH	800	n/a
Kyocera Finecam S3	Horiz LPH	820	* 1100
	Vert LPH	820	* 1050
	5^o Diagonal LPH	800	1000
Nikon Coolpix 885	Horiz LPH	* 1000	* 1350
	Vert LPH	950	1350
	5^o Diagonal LPH	950	n/a
Sony DSC-P5	Horiz LPH	1000	1350
	Vert LPH	* 1000	1400
	5^o Diagonal LPH	1000	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^o Diagonal	Lines set at 5^o 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.

Unfortunately it's here that the Optio 330 trips up, it's a little better than Kyocera's S3 but the Optio's little lens just doesn't have sufficient resolution to utilize that three megapixel sensor properly (this doesn't bode well for the Optio 430). It's interesting that both Sony and Nikon have managed to pull off relatively good resolutions with a compact lens (though not as compact).

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