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

[Kayaker72]

I think frame rate reduction is a potential issue .... do you think H mode would also reduce the frame rate using electronic shutter?

I am not sure. I have only minimally tested the electronic shutter.

The last day or two I have been thinking if the R5 autofocus tracking performs well with adapted EF lenses it could replace both my 5DS-R and 5DMKIV.

It could take a very long time to find out and may not be fully possible without trying it for myself.

When phrased like that, yes, I think so. Most importantly, yes, the best way to find out would be to test for yourself. As you have mentioned with the 1DX III, it is a bit surprising how few reviews have really come from wildlife photographers. With the R5 having characteristics that lend itself to video, portrait, event, etc types of photography, I am expecting most reviews to focus on its strengths there. With B&H's 30 day return policy, that is actually fairly easy to test yourself.

But also, yes, I expect the R5 to be able to replace both your 5DIV and 5DSr. Canon is pushing out the concept that the R5, with modern filters, will "out resolve" the 5DSr despite having a few less pixels. In terms of DR, as the 1DX III is just a smidge better at lower ISO than the 5DIV, I expect the R5/R6 sensors to be very similar to the 5DIV, but just a smidge better and a significant jump, especially at low ISO, over the 5DSr.

So, even slightly better resolving power over the 5DSr, the DR of the 5DIV, higher FPS, eye/head/face/animal auto-AF....yes, the R5 should be able to replace, and be a bit better in numerous ways, those two cameras.

[Jonathan Huyer]

As you have mentioned with the 1DX III, it is a bit surprising how few reviews have really come from wildlife photographers. With the R5 having characteristics that lend itself to video, portrait, event, etc types of photography, I am expecting most reviews to focus on its strengths there. With B&H's 30 day return policy, that is actually fairly easy to test yourself.

I have to agree --- the 1DX III has not been widely endorsed by wildlife photographers. There is a smidgen of reviews on YouTube, but not a big rush to embrace. The intended audience is really sports photographers, and with no sports happening these days you're just not hearing anything about the camera at all since the initial release. A friend of mine who is a Canon ambassador and pro wildlife photographer got one to try out for a bit, and he said he was struggling to get the AF to work for him. Now he's testing the R5 and he seems to enjoy it quite a lot. As for me I'm still really quite delighted with Mark III and find it a very nice step up from the Mark II. It's too bad that 20 MP is now considered inadequate (especially when compared to the R5). If nobody knew in advance that a particular image was taken with a "low" MP camera, they'd probably never realize it.