I am sure this has been discussed before but I just can't figure out why the 5D3 focuses so slowly when the AF assist is enabled on my flash. Many times I have been at a wedding reception and I get frustrated with very slow focusing issues related to the AF assist beam. I have messed around with turning it on and off and there is a very noticeable difference. For example with my 70-200 as long as I find an area of some contrast it will focus almost instantly even dark situations. As soon as I turn it on it sometimes takes a full second or two to lock focus. I remember my 5D2 having improved focus with the AF assist from the 580exII. Is it a flash issue or a camera issue? I know there are a lot of you who have the same problems. Anyone find any solutions? Most of the time I don't need the AF assist but when it is pitch black and I need it it would be nice if I could focus a little faster. I just don't understand how the AF can be so great in almost all situations except this one area. Of course when I call CPS they claim they have never heard of an issue.