7DMKII Focus keeper rate ideas?

[Marsu42]

Can the 7DMKII still do contrast detect AF?

Afaik af in live view is *always* contrast detect (supported), the phase detect pixels just give the contrast af hints where to go? This is exactly what I think...

I thought DPAF benefit was speed of live view focus?

.. or has this tech changed from the Rebels to the newest dual pixel af on the 7d2?

 

[racebit]

Well Graham, yes, you are right, standard contrast detection can be used to calibrate PDAF.
But I think DPAF can achieve a more precise focus. The reason being that DPAF not only tells which direction is right focus (so faster focus), but also that right focus is achieved when you get balanced data from both pixels. So it provides a real focus confirmation. Even if the DPAF were not more accurate than CD, the sum of the two sources of data (DP and CD) should provide a more accurate focusing.
Again, you are right, automatic AFMA should have been there before DPAF. But with camera processing power increasing greatly at each generation, there is less excuse for it not being there.
I think I will buy a 7D2, but DPAF turned out to be a useless piece of crap to me. I wanted DPAF for two purposes, and it does none of them:
1. Assist manual focus lenses (and telescopes, no electronics).
2. Assist AFMA.
And again point 1 could be made with CD, although not as practical, giving only a contrast number instead of a focus direction. But I would welcome the contrast number anyway. So easy to implement, no reason to not be there.
Furthermore DPAF can only be used with Canon lenses and not all of them. Ridiculous, when the concept should be used even with manual lenses.
So, again, to me DPAF is a useless piece of crap. Sorry to say that. I will still buy the 7D2 anyway, but obviously not for the DPAF.

Pedro

Hi racebit.
Wouldn't this have already been possible on anything that has live view focus? Or is DPAF significantly more accurate, I thought DPAF benefit was speed of live view focus?

Cheers, Graham.

People who want the best possible performance from high-end gear should expect to put in some effort to achieve that goal.

It is unfortunate that Canon did not use DPAF to assist PDAF calibration. That would be one of the most important features of DPAF. When 70D did not include it, I though it was because it was first iteration of DPAF, but I was confident it would present on following iterations. Very sad it is not.
The disadvantage of DPAF vs PDAF is speed, that is why we still need PDAF, but we do not need speed to calibrate.

So, yes I agree we should put some effort into calibrating the lens, but Canon should put some effort too, and Canon did nothing to assist the procedure and left all effort to the user.

 

[Valvebounce]

Hi Pedro.
Ok I now have a better idea of DPAF. So yes it would improve AFMA accuracy if it were enabled, and like you I don't understand why it is not.
As for it not working on all Canon lenses, or any 3rd party lenses that seems ludicrous to me but I guess there may be technical reasons for this and they're not just being bloody minded. :'(

Cheers, Graham.

Well Graham, yes, you are right, standard contrast detection can be used to calibrate PDAF.

Snip snip.

Furthermore DPAF can only be used with Canon lenses and not all of them. Ridiculous, when the concept should be used even with manual lenses.
So, again, to me DPAF is a useless piece of crap. Sorry to say that. I will still buy the 7D2 anyway, but obviously not for the DPAF.

Pedro