Steve Spencer wrote: : Steve Spencer wrote:
As usual with DXO looking at the measurements rather than the scores gives you a different picture. The Signal to Noise Ratio curves are basically on top of each other suggesting very similar noise performance throughout the range of ISO\'s, both are slightly better than the 5D MKII. Ditto for Tonal Range, which somehow is a major measurement category for DXO, but never makes it into their scores. For Tonal Range, if anything the 5D MKIII has a slight advantage. For Color Sensitivity, the D800 has a significant advantage, but this advantage is wholly attributable to the D800\'s higher resolution (note that if you click on the screen button instead of the print button the two graphs are again right on top of each other). This leaves us with Dynamic Range. Here the D800 has a big advantage at low ISO (100, 200, & 400) and a small advantage at 800. This advantage is due to a weird pattern in Canon\'s Dynamic Range that has been around for years. Canon\'s Dynamic Range isn\'t linearly related to ISO, instead it stops improving at low ISOs and is essentially flat at 800 and below. I\'m not sure this is a problem in real world shooting, but if it is then Canon should fix it but they haven\'t for years.
So, the sum total of being spanked in these ratings is that the D800 has higher Color sensitivity scores due to its higher resolution, which could easily be expected and Canon still hasn\'t fixed its lack of improvement in Dynamic Range scores with decreasing ISO. As usual if you look at the measurements there is a lot more similarity here than what the scores seem to suggest (for example the D800 gets a better Sports-low light ISO score despite the two SNR graphs being right on top of each other).
I\'m not saying that the D800 doesn\'t have a better sensor--it clearly does--just that as usual the DXO scores, as opposed to their measurements--don\'t accurately reflect either the magnitude of the difference or where the differences lie.
Tariq Gibran responded:
The big issue with rationalizing the discrepancy between the two in this way is that the higher MP sensor in the D800 has smaller sensels which logically should put it at an even greater disadvantage to the lower MP sensor in the 5DIII. The fact that the D800 sensor, even with it\'s higher MP/ smaller sensels, is still better justifies calling the 5DIII sensor \"spanked\".
It is not rationalizing. I have no horse in this race. Smaller sensels don\'t logically put the D800 at a disadvantage. As Brainiac showed endlessly a few years ago when the 1DsMKIII came out, higher resolution cameras are not at a disadvantage for high ISO if you standardize the output size. The same can be said for color sensitivity, downrezzing compensates greatly for the apparent \"logical\" disadvantage. DXO reports four measurements. On two of the four (Signal to Noise Ration and Tonal Range, the camera perform almost identically. On the other two the D800 has a clear advantage that can be further specified as I did above. I agree it is a clear win for the D800 as I suggested above, but I also think as is typical the DXO scores distort this advantage.
I don\'t believe DXO even considers resolution/ MP\'s as a variable. Traditionally, higher density/ smaller sensels are a disadvantage.
Apr 19, 2012 at 03:25 PM
Previous versions of Tariq Gibran's message #10559525 « D800 spanked the 5DIII in every DXO category! »
