Canon EOS 5D Mark III sensor review

I have finally received the datas of the tests conducted by my friends at DxO near paris on the sensor of the Canon EOS 5D Mark III. We are going to dive into these test results but I can already tell you that they are very surprising.

Canon EOS 5D Mark III vs Nikon D800

First, let’s measure the EOS 5D Mark III sensor review scores to the outstanding behavior of the Nikon D800‘s sensor on the DxOmark benchmark :

Low-light ISO : does the Canon EOS 5D Mark III benefits of its smaller pixel count ?

On a similar surface, the nikon D800 sensor contains 50% more pixels. The pixel pitch of the EOS 5D Mark III is 6.08 microns when the D800’s pixel size is only 4.7 microns. That allows Canon’s sensor to gather much more light per pixel. We find this extra light in the low-light ISO score of the EOS 5D Mark III, but not as much as we’d expected. The 100% displayed image (screen result) of both sensors give a slight advantage to the Canon sensor, but again, I would expect more ISO headroom on a 23 megapixel sensor compared to a 36-megapixel one…

Things get worse when you compare the “print” test result where DxO polishes the scores on the basis of a A4 print. Then, the small extra noise amount is more than balanced by the extra resolution which dilutes the grains and make it disappear. Therefore, the final sensibility score of the Canon HDSLR is 1/5EV less than the Nikon D800 ! That is a surprise.

Dynamic range : Canon EOS 5D Mark III = Nikon D800 – 2.3EV

Surprise ! I warned you. Looks at the dynamic range curves of both cameras. See how, from the highest sensitivities to the lowest, both DSLRs offer an equal dynamic range. But the curves take different paths at ISO 1,600 and bellow : the Canon EOS 5D MArk III dynamic range does not improve very much when you decrease its ISO setting to ISO 800, 400, 200 and 100, while the Nikon D800 DR is boosted by the ISO reduction. At the end, at ISO 100, the gap is an outrageous -2.3EV. That is a lot for two high-end DSLRs that are meant to be sold till 2015… Canon struggles developing its own sensors on the dynamic range field. Having more dynamic range means a lot to a photographers. That means more exposure freedom, more details in the dark / bright areas, more RAW postprocessing room and the ability to take one shot HDR images.

The maximum dynamic range of the Canon EOS 5D Mark III is a poor 11.7EV. It is the 49th camera on DxO chart on this criteria. The nIkon D800 maximum DR is 14.4EV. That is a lot. It is number one.

To summ the EOS 5D Mark III vs D800 fight up, the sensor of the Canon does not takes full advantage of its smaller pixel count. The slight extra SNR wil be offset by the D800 larger resolution and the screen displayed difference is not reproduced on the prints. In terms of dynamic range, the Canon EOS 5D Mark III clearly under performs an dis a big deception. It DR is very low and not in todays standards. For these two criteria, the 5D MK III JPEG are very well processed and Canon’s tends to improve the final results. But the RAW files potential is simply not there.

Finally, le me remind you that we are comparing the Canon EOS 5D Mark III to the Nikon D800, the camera which is number one of DxO chart and has got impressive test results (see the Nikon D800 sensor review).

Canon EOS 5D Mark III vs Mark II

You may wonder what progress has been made in 4 years of R&D by Canon engineers between the two generations of Canon HDSLRs. Well, here are the measurements :

Low-Light ISO : Clearly, both cameras have the same pixel count. One single megapixel on a full frame sensor is not significant. The gain is only 1/4EV. That is weak and means NO improvement for RAW shooters. On the other hand, in JPEG, the Mark III is known for offering around 2EV better images, but in JPEG only and you will miss the advantage of powerful RAW softwares noise reduction. A reader commented last week on my Facebook Page and observed that the EOS 5D Mark III images were noise free, even at ISO 12,800.

Dynamic : Status Quo, nothing improved, Canon has really failed bringing more exposure latitude to the 5D Mark III.

Color depth : same as above. No significant improvement.

Comparing the Canon EOS 5D Mark II and the EOS 5D Mark III is useful for the photographers who use the Mark II and wonder which image quality improvement they may expect if they by the upgrade. Well, in JPEG, there is really better image on the Mark III but what is the pourcentage of photographers using the EOS 5D in JPEG ?… If you shoot RAW, you will not get anything really better. (note that the Mark II image is already outstanding). But as you may already be aware of, the main assets of the 5D Mark III are its new body, weather sealing, autofocus, exposure metering…. and that is worth the upgrade if, just like me, you were tiered of the poor autofocus and viewfinder of the Mark II.

Canon EOS 5D Mark III vs EOS-1D X

Canon EOS 5D Mark III sensor review