Is the DxO sensor score arbitrary?

[dreed]

Now that DxO have released the testing numbers for the Canon 1Dx, I thought I'd have a look at how it stacks up against the D4 and 5D Mark III.

Vs the D4, the 1DX is -0.9 on colour depth, -1.3 on dynamic range and -179 on low-light ISO. The DxO score difference is "7".

Vs the 5D Mark III, the 1Dx is +0.2 on colour depth, -0.1 on dynamic range and +493 on low-light ISO. The DxO score difference is "1".

Does that seem right?

[BobFisher]

As I read the scores, the 1Dx is -7 compared to the D4 and +1 compared to the 5D Mk III.  It underperforms the D4 in all three sub-score categories.  It outperforms the 5D Mk III in two of the three sub-score categories and underperforms in the third, but not by a lot in any case.  Given that the overall score is based on the three sub-score categories, the overall scores seem reasonable.  The two Canon bodies are very close in performance and the Nikon outperforms both in all three categories.  The greater than 1 stop difference in dynamic range is substantial and would, I'd think, be the primary reason for the bigger difference in favour of the Nikon.

[Fips]

Also keep in mind that DxO that there is a statistical error. I remember having read a statement from DxO that it is on the order of 5 points. The real-world differences could therefore be much smaller than the numbers suggest.

[jeremypayne]

... The DxO score difference ...

I find the overall score to be basically useless ... the individual components of that score, IMHO, are not ...

[BobFisher]

Also keep in mind that DxO that there is a statistical error. I remember having read a statement from DxO that it is on the order of 5 points. The real-world differences could therefore be much smaller than the numbers suggest.

Can you point to documentation that supports this?

I agree with Jeremy that the overall number isn't as important as the individual areas.  One or another may be more important to one person or another.  And, in the end, DxO is only one of several 'reputable' review sources.  Imaging Resource being one that seems to often get overlooked.

[Fips]

I can't find it anymore. If I remember correctly, it was in a FAQ which seems not be be on the website anymore. However, they do say that  "a 5-point difference on the scale corresponds to a gain or loss of sensitivity of 1/3 of a stop".

[ErikKaffehr]

Hi,

Yes and now. I have two Sony cameras Alpha 900 (full frame) and Alpha 77 (APS-C) both are 24 MP. According to DxO mark they are very close and I think they actually are. So I'm skeptical about the figure but it may be not so bad at all in the end.

The data beneath is probably OK.

Best regards
Erik

I find the overall score to be basically useless ... the individual components of that score, IMHO, are not ...

[kers]

Looking at the Nikons i have owned  D800e,  d3x, d3, and D2x  - their measurements represent very good my own reflection.
Looking at the Sports (Low-Light ISO) ratings i see that the numbers represent exactly the highest iso i like the shoot the specific camera.

If i see that the d800e has 8 point more than the d3x - these 8 point are really important in real world images
High ISO about 1,5-2 stops better  - dynamic range better-  color stays beautiful till 6400 asa instead of 1600 asa...

[Vladimirovich]

Also keep in mind that DxO that there is a statistical error. I remember having read a statement from DxO that it is on the order of 5 points. The real-world differences could therefore be much smaller than the numbers suggest.

we have measurements done/collected/prepared by William Claff that you can use as an alternative source (and compare w/ DxOs) = http://home.comcast.net/~NikonD70/|

his comparison of his data vs DxO data = http://home.comcast.net/~NikonD70/Charts/PDR_Landscape.htm

which says that DxO, like it or not, tells the truth.