Compared to the Nikon Coolpix 990 (contd.)
Distant Detail Comparison
|Canon G1 @ ISO
||Canon G1 @ ISO 100||Nikon Coolpix 990 @ ISO 100|
Blue... Yes, the G1 did much better, I've no idea why the 990 didn't pick up the blue (ignore the top of the image because it's blocked by the cloud). The 990 does surprisingly well at ISO 100, very little visible noise, having said that the G1 ISO 50 image is still the cleanest. Neither have more or less detail, but the G1 has better colour.
|Canon Powershot G1||Nikon Coolpix 990|
To me, the 990 image is darker with a strange blue cast on the wall but fairly good skin tones, the G1 image is a little pale but lighter and no cast on the wall. It's tough, somewhere between the two would probably have been the perfect image. Jo would like me to point out that the "Wanted poster" pose was my idea... (d-oh).
Colour Chart Comparison
Shot in daylight, Auto White Balance, EV compensation +0.3 (all cameras), measured light ~10 EV.
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.
|Canon PowerShot G1||Nikon Coolpix 990|
"Warmer" overall, there's a very very very slight red cast over light areas of the G1's colour patch shot, other than that it's really a matter of taste. Notice that the G1 has maintained the lower end of the gray scale better.
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.
|Canon PowerShot G1|
|Nikon Coolpix 990|
Measurable findings (three measurements taken for each camera):
|Camera||Measurement||Absolute Res.||Extinction Res.|
|5o Diagonal LPH||900||n/a|
|5o Diagonal LPH||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)|
image detail. Beyond the Nyquist frequency aliasing occurs.
It was so close, I spent a long time pouring over the G1's resolution chart, it defintely has a very slight resolution edge on the 990, but it's really VERY VERY CLOSE. The trade off for that extra resolution is increased moiré (blue / yellow banding).
Red Channel Noise (Blue Sky Noise)
Something we noticed early on with the current crop of 3 megapixel cameras was a certain amount of noise in the red channel, even at normal shutter speeds. This was normally 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 image below shows the red, green and blue content of the blue & cyan patches from both the G1 and 990. We deliberately included both ISO 50 and ISO 100 samples from the G1 "to be fair" to the 990 (as any CCD will produce less noise at lower ISO's).
I think it's fairly plain to see that Canon's implementation ISO 50 virtually illiminates any noise in light blues making it the perfect choice for daylit scenes (as there'll be plenty of light to shoot at ISO 50) there's also a much better "purity" in the G1 colours, the 990's looking oddly cast. Even at ISO 100 the G1 performs better than the 990 for light blues, the 990 just pipping the G1 for dark blues.