Quote Originally Posted by Joel Eade View Post
The low light performance of the 1DX is truly amazing too but it does struggle with AF tracking quite frequently when shooting birds in flight and believe me I have tried extensively with different AF settings. I have shot side by side with D850 and a9 users who were getting way more sharp images shooting the same subjects. I just have no doubt those bodies have much better AF tracking.
Absolutely yes --- that was a sore point with me and my Mark II. The Mark III is a massive upgrade in tracking, hopefully bringing it up to (or even beyond) the level of the D850 and a9. But I have no doubt that the R5 will be just as good. Maybe even better, since you're focusing with the sensor instead of a separate system. And the firmware for the focusing logic sounds like it is more advanced, in terms of subject detection.