Originally posted by rawr But the new Canon and Nikons are both going to be FF. Relatively speaking the D7000 result will be more interesting.
Not all of us are DXO flip-flops. Some of us have been DXO fans for quite a while. I used to get all sorts of flak about DXO myself here a while ago. Numbers and tech evaluations are always good and necessary when you are talking optics and electronics. But they can always be mis-interpreted.
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I like DxO, it provides a valuable touchstone for individual sensor attributes, but the 'overall score' is defined as:
Quote: What does Sensor Overall Score show?
* Sensor Overall Score shows:
o the quality of the sensor in terms of noise.
o the ability to render high contrast.
o the formation of colored noise.
o the ability to shoot in low light.
* Sensor Overall Score does not show:
o the resolution of the camera, i.e., its ability to render fine details.
o the quality of the lens.
o the optical aberrations.
How is it measured?
The Sensor Overall Score is an average of the Portrait Score based on Color Depth, the Landscape Score based on Dynamic Range and the Sports Score based on Low-Light ISO.
If you look at the Portrait, Color, and Low-Light score descriptions, it doesn't really bring any insight into their formula to derive the ovrall score. (again, unless I miss that formula.) So, the overall score is useful as a better-than-average subjective measure, and can be a feather in the cap that increases sales, but isn't as useful in determining the worth of the camera to your needs as looking at the individual attributes would be.
Personally I find the 'sports low-light' attribute score interesting, because it describes a real-life shooting situation that meets a big chunk of my needs - the 'sport' of low-light kid/family shooting. Toddlers are slow-moving athletes, but they're often moving in even lower light than, say, a gym or soccer field.
Here's that attribute description:
Quote: Sports & action photography: Low-Light ISO
Unlike the two previous scenarios in which light is either generous (studio) or stability is assured (landscape), photojournalists and action photographers often struggle with low available light and high motion, so that achieving usable image quality is often difficult when pushing ISO.
When shooting a moving scene such as a sports event, action photographers’ primary objective is to freeze the motion, giving priority to short exposure time. To compensate for the lack of exposure, they have to increase the ISO setting, which means the SNR will decrease. How far can they go while keeping decent quality? Our metric, Low-Light ISO, will tell them.
The SNR indicates how much noise is present in an image compared to the actual information (signal). The higher the SNR value, the better the image looks, because details aren't drowned by noise. SNR strength is given in dB, which is a logarithmic scale: an increase of 6 dB corresponds to doubling the SNR, which equates to half the noise for the same signal.
An SNR value of 30dB reflects an excellent image quality. Low-Light ISO is then the highest ISO setting for the camera such that the SNR reaches this 30dB value while keeping a good dynamic range of 9 EVs and a color depth of 18bits.
As cameras improve, the Low-Light ISO will continuously increase, making this scale open.
A difference of Low-Light ISO of 25% represents 1/3 EV and is slightly noticeable.