Canon EOS R6 Mark II Sensor Measurements at PhotonsToPhotos

SigZero wrote:

johnpul wrote:

silentstorm wrote:

Great info as usual. Interestingly both old and new R6 exhibit similar measurement, ie. DR is reduced using ES at the lower ISO.

Why is this so? Fuji, Olympus, Sony, Nikon, etc don't have such gaps when using ES vs MS.

Any ES measurement for the R10 and R7?

Thanks.

I believe the electronic shutter is lower bit (12?) files and therefore lower dynamic range — could be wrong

Yep it's probably due to Canon's ES still being limited to 12 bit read-out. It's common in all R bodies.

It's to keep from an even slower rolling shutter.  If you run a comparator ADC circuit for 14/12 as long or 16.67% longer, you rolling shutter is going to be roughly 16.67% slower.

Note that the 2 stops of greater DR at base ISO with 14-bit readout is going to be solely from 2 stops less post-gain read noise, so if the post-gain read noise has more spatially-correlated noise than the pre-gain read noise, that merge of 12-bit and 14-bit readout at higher ISOs really isn't true, regarding visible deep-shadow noise, as the post-gain read noise is going to be 2 stops higher in 12-bit noise up the ISO scale, and increase further as soon as arithmetic gain kicks in in "extended" high ISOs.  I noticed early on with my R5, switching between EFCS and ES at ISO 51.2K showed more horizontal banding noise with ES, despite the fact that the contribution of post-gain read noise in quadrature with pre-gain read noise is statistically infinitesimal in a monolithic noise measurement.