600D lag with 580 EX II af assist

[steliosk]

Hi there.

i don't know if you've noticed this:
i have an 600D and 580 EX II
whenever i want to use the af assist (red beam of the flash) it focuses way slower rather than my old 350D and 450D which focused instantly with the beam in low light situations.

Tested in the same room, same lens (24-105L) and 580 EX II in both cameras 600D vs 350D
the 350D focuses INSTANTLY with the beam, while the 600D hunts and laggs

have you noticed that?
probably a bug that is fixable with a further firmware update for this camera. No reason why the older hardware works fine instead of this?

[Marsu42]

probably a bug that is fixable with a further firmware update for this camera. No reason why the older hardware works fine instead of this?

Same issue exists on the 5d3 - so newer hardware does have regressions. Since I have a 60d (same hardware generation as 600d) I can only comment that it is very quick to af with af assist. And looking at how Canon acts, it is extremely unlikely thy would fix something like this on a Rebel if the 650d is already out.

[steliosk]

thanks for the reply.
have you tested your 60D with an older camera? any differences?

i haven't tested the 5D 3 with 580 EX II
are you suggesting that i should change a flash unit?

[Marsu42]

thanks for the reply.
have you tested your 60D with an older camera? any differences?

nope, but the 60d fast with af assist to I can hardly imagine an older camera being much faster (but feel free to correct me :-)).

i haven't tested the 5D 3 with 580 EX II
are you suggesting that i should change a flash unit?

The 600rt af assist beam is the only one compatible with the full 1dx/5d3 af points spread, so no need for you to change on the 5d2. On the 5d3 it it has the same lag as the 580ex2 - or not, depending on different people and if you are willing to make the camera release the shutter before the actual af lock - read the threads for yourself, it seems to be an issue to some.

[Area256]

I found on the 60D with the 580EX II that my flash wasn't sitting exactly in the right place in my hot shoe.  There was a little wiggle in the position, and that causes the AF assist beam to miss the AF point.   Try focusing in a dark room on a white wall, see if your focus assist beam actually hits your selected AF point.   Not sure if this is your issue, but it solved my problem.