5D3 + AF assist beam = slower focus

[Carerra911]

Hello All,

While I am new on these forums I have been on the Canon Rumors Forums for a few years now, 

I really wanted to bring this too the attention of you and Canon as it is simply a highly important problem, those of you that don't know, the 5D3 suffers serious focus locking issues when a Canon speedite is attached in Low light, the AF assist beam causes lag with the AF from the 5D3, this makes it virtually impossible to achieve focus in low light when the speedlite is attached, I wanted to bring the topic to this forum, so I have pasted a link to all the discussion we have already had about this problem at Canon Rumors.com - see below

http://www.canonrumors.com/forum/index.php?topic=10275.0

Please help in letting Canon know this is a very serious problem and effects the cameras performance in most working environments when a speedlite is attached and working in low light, conferences, nightclub work, weddings etc, and can stop the photographer completing the job or task.

Regards

Louis

[echelonphoto]

I would like to add my 2 cents also. I have shot for 6 years with the Canon full frame bodies...first the orig. 5d, then two of

the Mark2's....just got a mark3 and I noticed right away at a reception...as I was doing group photos using the center focus

spot in one shot mode....there was a distinct delay that is definitely not there in mk2....this is with the AF assist in indoor

lighting that is not even that dark. Never had a problem with the Mk2 and center spot with a flash attach...it is instant and I

can even follow action in a fairly dim room with it. The mark 3 is def better in AI servo mode, which is great...but I need that

one shot ability for portrait and reception shooting. I am using the 600 rt flashes with my cameras.

The one thing I can say is when the mk3 does focus fully...it always nails it accurately which is something the mk2 sometimes slipped up on.

[echelonphoto]

This is info for Mike....I was using mainly the 24-105 lens...tried fine spot focus, regular spot focus and center group focus...

all in one shot mode. Most distances are about 8-12 feet and lens maybe zoom between 24-40mm.

[digital]

This is interesting. 

http://www.canonrumors.com/forum/index.php?topic=10706.45

[ScottyP]

Will someone who gets a 6D please post your view on whether this issue is present in that camera as well?  I might just buy a 6D, but this would be a big deal to me.  Thanks!

[echelonphoto]

Hey Mike,

       I repied several days ago....this is a REAL problem for shooters like me who have tons of experience in the field...

please have Canon address this...there is no work around for a the photographer....I just wasted 3200 dollars...could

have kept my main mark2...now I have to shoot with my backup camera...another mk2...or make the painful leap to

Nikon

[Carerra911]

Im glad you are all replying guys, as everyone has stated, this is a very big deal.

[DeckardSolo]

I tested the IR beams of the 600ex-rt, 580ex2, and ST-E2 on my Rebel T2i/550D and 5D3 and the Rebel is focusing at least 1/2 a second to a full second faster than my 5D3 in near pitch black at a blank/tiled wall at 8 feet. 

What I noticed was that regardless of which flash was used the Rebel would focus during the 1st to 3rd IR beam pulse whereas the 5D3 focused on the 3rd or 4th pulse.  Most significant though is the Rebel pulsed the IR beam at a much faster rate than the 5D3, about at least twice as fast.

[Used 24-70 f/2.8L and 70-200 f/2.8L IS II with focus started at minimum focus distance.]

[marcdegroot]

i sent it off to canon for them to have a look at.

i got it back with an explanation that there was dust in the AF sensor and has been sorted. hmmm.

ive yet to try it out in a real situation, im expecting it to be the same.

[digital]

Really? I can hardly wait for your feedbabck on this. Kinda seems a little sletchy to me.

[echelonphoto]

Any more news...I am really getting frustrated with this camera....went back to my Mark2 this weekend...just missed too

many shots with the mark3 because of slow focus...can't trust it.