
Compared to Nikon Coolpix 990 and Olympus C-3030Z
Contd.
Colour Chart Comparison
Shot in daylight, Auto White Balance, EV compensation +0.3
(all cameras), measured light ~10 EV.
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Sony DSC-S70
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Nikon Coolpix 990 |
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Olympus C-3030Z
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It's a close run thing. All cameras showing good daylight
white balance and good metering. There is little between the three cameras
in this test, the S70 producing slightly stronger colours.
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.
| |
Sony DSC-S70 |
Coolpix
990 |
Olympus
C-3030Z
|
| Patch White |
182,182,182 |
201,201,201 |
197,197,197 |
| |
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| Middle Gray |
85,85,87 |
104,104,104 |
92,92,92 |
| |
|
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| Patch Red |
189,17,27 |
223,52,58 |
191,21,21 |
| |
|
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| Patch Green |
1,132,35 |
5,149,63 |
0,140,52 |
| |
|
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| Patch Blue |
33,26,123 |
60,50,112 |
56,41,102 |
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Resolution Comparison
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.
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Sony DSC-S70
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Nikon Coolpix 990
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Olympus C-3030Z
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Measurable findings (three measurements taken for each camera):
| Camera |
Measurement |
Absolute Res. |
Extinction Res. |
| Sony DSC-S70 |
Horiz LPH |
1050 |
1400 |
| Vert LPH |
1050 |
1500 |
| 5o Diagonal LPH |
1000 |
n/a |
Nikon
Coolpix 990 |
Horiz LPH |
900 |
1300 |
| Vert LPH |
900 |
1400 |
| 5o Diagonal LPH |
900 |
n/a |
Olympus
C-3030Z |
Horiz LPH |
900 |
1350 |
| Vert LPH |
900 |
1350 |
| 5o Diagonal |
900 |
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.
Well, there you have it. The S70 definitely has more
resolution than its nearest competitors the Coolpix 990 and Olympus C-3030Z.
Sony have achieved this through the use of a good quality large factor
lens system and a quality in-camera processing algorithm.
Red Channel Noise

Not surprisingly the S70 produced very little red channel
noise in blue or light blue shades, certainly not as much as we'd seen
on the 990 and C-3030Z. Whether this is down to the CCD, electronics systems,
algorithms or JPEG compression it's there in the final image and therefore
becomes visible in certain circumstances. That said, this noise can be
corrected using third party tools.
The samples above are of 50 x 50 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.
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