Compared to... (contd.)
Colour Chart Comparison
Now we can compare the CD200 to a couple of other cameras, using samples from our test archives we will now compare its image quality to the Olympus C-2020Z, Canon PowerShot S10 and Nikon Coolpix 950.
Colour charts are shot in daylight, Auto White Balance, EV compensation +0.3 (all cameras), measured light ~10 EV.
|Sony MVC-CD200||Nikon Coolpix 950|
|Olympus C-2020Z||Canon PowerShot S10|
Obviously the CD200's auto white balance had real problems here, despite being taken in exactly the same position with the same light source as the other cameras.
We're only measuring colour here. 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.
Ignoring the slight green cast it's obvious that the CD200's colours are stronger and cleaner than those found on these similar 2 megapixel digital cameras. Overall excellent performance (if only the auto white balance had worked properly).
Red Channel Noise
Something we've commented on previously is noise in the red colour channel in what should be pure blues. This was most visible in the light blue of skies or painted walls. Our colour patch test chart turned out to be a good "leveller" and a way to measure the performance of one camera to the next.
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 below.
As we'd expected the CD200 does well, indeed most 2 megapixel digital cameras seem to perform better in this test than their 3 megapixel counterparts.
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.
|Nikon Coolpix 950|
|Canon PowerShot S10|
Measurable findings (three measurements taken for each camera):
|Camera||Measurement||Absolute Res.||Extinction Res.|
|Sony MVC-CD200||Horiz LPH *||850||1050|
|5° Diagonal LPH||800||900|
|Nikon Coolpix 950||Horiz LPH||750||1050|
|5° Diagonal LPH||800||n/a|
|Olympus C-2020Z||Horiz LPH *||800||1100|
|5° Diagonal LPH||900||1000|
|Canon PowerShot S10||Horiz LPH||850||1150|
|5° Diagonal LPH||700||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.
A good performance and about what we'd expect of a "second generation" 2 megpixel digital camera, performance is up there with the highest we've tested (the Canon Powershot S10), combine that with the excellent colour reproduction and the CD200 is beginning to look like the best 2 megapixel we've seen so far (for image quality).