(Megapixels) War...what is it good for....

[Joel Eade]

My interest in mirrorless (as opposed to upgrading to the 1DXIII) was originally to fit a niche .... that being a smaller, lighter rig with stellar AF tracking for birds in flight.

I wasn't so much motivated by sensor resolution and was seriously considering the Sony a9 (also 20 mp).

I have been satisfied with the resolution of the 1DX. You (and others) have certainly proven that glorious images and large prints can be done with 20 mp.

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.

The R5 interests me mostly because of it's reported AF tracking.

If the R5 can provide AF performance equivalent to the a9 with more pixels too then, to me, that is a win-win because of more "crop ability"

If it is the consensus that the R6 is significantly better at AF tracking or that the reduced ISO performance of the smaller pixels is a big problem I would certainly consider the R6.

One more point, for my purposes the R lens line up is not yet optimum: I wish there existed an R mount 500 or 600mm f/4 DO lens. (a built in 1.4 TC would be really cool)

So, if I take the plunge, I will probably try my existing EF lenses first.