How good really is the 5D4 AF?

Reviews say it's the same AF system as in the 1DX2, but is it really that good? I thought the IDX2 had a separate processor designated to the AF that the 5D4 doesn't have. Who owns (or at the very least) has used both? Are they virtually the same or is there a difference?

There are some differences between the 1 and 5 cameras.

The 5d4 has a separate digic 6 for Af and metering (this is on the canon spec list on their site. The 5d3 did not have this.). Its metering sensor has less pixels plus a lower fps rate.
Also the 1dx II has AI servo III+ and the 5d has AI servo III (i can not find what that actually means in practice).

I do find the 5d4 much faster to lock than the 5d3 and if it loses lock on say a bird in flight it reaquires quickly. I used to find on the 3 if the lock was lost it was gone. Im not the greatest handhold shooter but the 4 compensates well

Ive never used the Idx II or even the I so I cant compare.

Jarvis Creative Studios wrote in post #18237225
Reviews say it's the same AF system as in the 1DX2, but is it really that good? I thought the IDX2 had a separate processor designated to the AF that the 5D4 doesn't have. Who owns (or at the very least) has used both? Are they virtually the same or is there a difference?

First off, I own neither. It does cross my mind that the frame rate of the 1DX2 REQUIRES that body to have a separate processor for AF. Both cameras are doing essentially the same thing. The 1DX2 is doing it twice as fast. That speed has to come from somewhere.

I have both and the most noticeable difference is the ability of the 1DX2 to focus in low light whether in single shot or servo mode. I have not done a formal test but i would guess that it is as much as 1/2 EV stop better.

Thanks for the responses. I have found my 5D3 quite lacking in the AF department as of late. Especially if light isn't perfect. I'm planning on sending it in to Canon as it has not been serviced in a few years. Soon I'm planning on upgrading though and was simply weighing my options.

I don't have a 1DX II but has a 5D3 and went to a 5D4. AF is snappier with my 5D4 I have yet yo you BIF. Winter has hit hard and finding flying birds is not easy this time of year. I'm enjoying the extra megapixels and it as many features my 7D2 has and you get all AF points @ f8

100-400 II and 1.4 III

I have both and the 1Dx2 is faster hands down. Don't get me wrong, the 5d4 is awesome in its own right and is much better than the 5D3 ever was. It's just that the 1DX2 can drive the lenses faster than the 5 series can. For instance, the 1Dx2 can run the 85L to infinity and back in about the time the 5d4 can just get it to infinity. They are both very accurate but the differences in speed is noticeable

That is to be expected for almost twice the cost.

digital paradise wrote in post #18237685
That is to be expected for almost twice the cost.

So true. What I want is the 5d4 sensor in the 1dx2 body.... Dream scenario for me lol

David83 wrote in post #18237693
So true. What I want is the 5d4 sensor in the 1dx2 body.... Dream scenario for me lol

LOL. I want a crop with a dedicated AF processor. Another dream.

digital paradise wrote in post #18237698
LOL. I want a crop with a dedicated AF processor. Another dream.

Wrong. Buy a 7D. Done.

I have a 7D2.

David83 wrote in post #18237693
So true. What I want is the 5d4 sensor in the 1dx2 body.... Dream scenario for me lol

All I want is a pro Canon body with a flip screen. Canon isn't in the business of fulfilling dreams unfortunately.

But they (Canon) are fulfilling my dream by not putting a flip screen on my 1DX.

I don't want Canon to waste R & D on useless (to me) features such as WiFi, GPS, Video, get rid of IS in their lenses etc etc - If they make you happy they will upset me and if they make me happy they will upset everybody