Hi,
DxO-mark sensor is about noise. How clean signal the sensor can deliver. DxO actually measures colour accuracy, using a standard called SMI, but that is not a part of DxO-mark.
Now, DxO-mark is not a bad thing. It is based on three sets of parameters:
- Dynamic range -- abiliity to reproduce shadows in a a correctly ETTR exposed image.
- Maximum ISO for acceptable reproduction
- Number of colours resolved at different ISO
Each of these metrics are well founded and may even be relevant.
BUT, essentially all cameras are good enough.So, the differences that are measurable may matter little, as they are far beyond observable limits.
The reason that Nikon leads far beyond Canon is that it can extract far more detail in the shadows than Canon at base ISO. It may matter a lot if you shoot base ISO on tripod and high contrast subjects. But, whenever you go past say ISO 500 or so, Canon will be a good match for any Nikon or Sony.
Look at DxO-s sports rating, and results will be different.Lenses are quite different. Take two decent lenses at say f/8. They will be very close. If you shoot at f/8 a 300 $US lens will perform close to a $3000 $US lens. But, the 3000 $US lens may bring decent or even near perfect performance at f/1.4. That is what you are paying for with an Otus. Shoot at f/8 and any decent quality lens will be a decent match for an Otus.
Now, an Otus lens can deliver near perfect image quality at f/1.4. If you need that the Otus will deliver.
DxO-mark for lenses tries to take large aperture performance into account. If you want to have maximum image quality and shoot medium apertures, DxO-mark will present a pessimistic view of lenses. But, if you want to take very sharp pictures with a very thin zone of focus using large apertures, DxO-mark will make sense to you.
So, DxO mark gives a good information about the system,
if you take it to the limits, but for normal work at medium ISO, medium aperture and so on most sensors and lenses will do an excellent job, leaving DxO-mark irrelevant.
Best regards
Erik
A quick look at DXO Mark tells you that the Nikon 810 has the best sensor - with the Canon 5d Mark 3 far behind - and the Zeiss lenses out perform most of the rest of the pack.
This is a strong message, so I would like to know exactly what these ratings mean.
For instance, it seems that for different camera bodies, the same lens can perform differently and all lenses seems to lose some of the pixel count that the camera theoretically provides. So a lenses on a 22 megapixel camera may only resolve 18 megapixels. Why do lenses lose information like this? Does a Canon 5d Mark 2 at a an overall rating of 82 fall far short of the Nikon 810 with a rating of 97 - or is this just 22 versus 36 megapixel difference?