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cgarcia
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Re: Official: Canon Announces the EOS 6D Mark II


Very, very dissapointing. Very sad news.

Nobody would have expected this: The 6D2 dynamic range has not been upgraded.

The 80D is a better landscape camera.

The 6D2 only achieves about 11.9 EV of dynamic range, once scaled to the standard DXO metrics. This is aproximately 1.7 EV under the 5D4/1DX2/80D performance (to mention a few recent Canon cameras). This has been estimated using the provided RAW file and measuring the masked pixels noise (will will match the DXO review with nearly 99% confidence).

My take: Canon either has made the 6D2 an high ISO beast a la Nikon D5 (which has also a poor low ISO dynamic range) or has decided to keep the dynamic range as a 5D4 feature. Anyway, this will indeed affect a lot of purchasing decisions. I'm personally not worried because my next step after the 6D will likely be the 5DS2 (unless Canon doesn't upgrades its dynamic range, a very unlikely error on that model).

Here follows the technical details:

At the pixel level, the ISO 100 provided image (IMG_9106.CR2) reaches 11.04 EV at 26MP (11.89 normalized to 8MP) compared with my 6D which reached 11.53 EV at 20MP (12.19 EV normalized to 8MP). The measured read noise is 7.53556 DN (compared to about 4.68699 DN in my 6D). The new sensor uses a 512 blackpoint at ISO instead of 2048 (just like the new crowd of sensors). But unfortunately doesn't achieves their dynamic range performance. The measured white point is 16383, which could point to a preproduction camera (my 6D doesn't seem to top there at ISO 100) so the real dynamic range could be even half a bit less.

To reproduce the results (or to test other pictures or another cameras):

1) Download the dcraw tool (https://www.cybercom.net/~dcoffin/dcraw/) and run:

$ dcraw -E -4 -j -t 0 -s all IMG_9106.CR2

2) Open the generated PGM file with a image editor and visually determine the area of the masked pixels at the top and the left. For a given sensor it is the same for all the pictures (for the 6D2: 120 pixels at the left and 44 at the top).

3) Download the hraw tool (https://github.com/lightful/hraw, a Linux PC is still required) and run:

$ hraw analyze -i IMG_9106_0.pgm -m 120 44 -c G

Which will output (using a safe crop of the left masked pixels):

ReadNoise=7.53556 [email protected]=11.0403 [email protected]=11.8956 file { IMG_9106_0.pgm }
image { mean=2718.27 min=405 max=16383 } left mask { mean=512.686 min=479 max=550 crop=56x4172+2+48 }



Jul 07, 2017 at 05:35 PM





  Previous versions of cgarcia's message #14098826 « Official: Canon Announces the EOS 6D Mark II »