Ok. Just played with this on my 5DIV and R5. If I have done the math correctly, your image was -4.67 EV.

Even borrowing our cat for good comparison:
5DIV PDAF would not AF. Not a chance.
5DIV DPAF (live view). Some hunting, but would AF.
R5 Spot AF (DPAF). Definitely struggled, but I did get occasionally AF.
R5 Single Point AF. Some hunting, but fairly good.

I should have tried expanded point AF. Next time.

Next, I tried even darker with the R5, somewhere around -5.5 EV. Spot AF, no go. Single point AF would work. It was slow, needed some contrast, but it would work.

So, my takeaway is more that the PDAF on the 1DX III has impressive low light abilities. Actually outperforming it’s spec. Considering how incredibly dark these rooms were, I am absolutely fine with the R5’s performance.


Sent from my iPhone using Tapatalk