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5D3 + AF assist beam = slower focus


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 - see below



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.




180 REPLIES 180

Yes. Outstanding. Thanks Canon.



Thank you Naomi  for your reply, Its nice to know you are there, Look forward to hearing from you and to getting a conclusion to the problem,




"make the EOS 5D Mark III ideal for shooting weddings in the studio or out in the field"  [direct quote from]. 


Wonder if Canon are having to be really cagey here in case they are getting into Law suit territory with this?

I don't believe they would have responded with "we hear you and will have an update" unless they found they could do something about it. If it was a hardware issue they my have tried to ignore it as that would get pretty costly. AF issues are going to get a lot more noise than this.


They may have known and just decided that photogs would accept it in return for a higher percentage of keepers.  Obviously that few seconds is very important to a pro and hobby shooters as well.


My guess is it got missed during testing. No matter how good people are at something they miss things and make mistakes. The person could have tested and got great results and moved on. The next time the person may have noticed it.


That is why quality control does not work because people are involved. Can you imagine checking the same thing day in a day out for 8 hrs a day? Someone kill me slowly with a tooth brush. The Japanese system relies on producing a defect free product during manufacturing thus eliminating quality control which a bottle neck and is costly. It is one of the 7 deadly wastes in the lean manufacturing method which was created by Toyota (not to mention others). They may check a sample group but I doubt every unit gets checked and I doubt they would check AF assist beam performance.    


That little off topic thing was just an example. How could Nikon release some of the D800 series had a blue or green LCD (I think) I read about the other day?  I did not pay a lot of attention to it but there was an issue. You think someone would have noticed it.  Maybe the testers got non defective screens? Claims were made that Nikon knew and shipped then but that is just speculation and can't be backed up.


There is variation in every product we purchase. We have read that some people don't have this problem. A variation during manufacturing or an issue that affected all 5D3's?                      


I was a little concerned at first because my 5D2 was excellent at AF lock with the AF assist beam.  I sold it and took a hit upgrading for the pro AF which I'm very impressed with. This issue has not effected yet but I don't need any surprises and don't want to switch to my 7D in the heat of the moment. Both great cams but have their own jobs.


I am now confident Canon will resolve this.          

A slow week on this new news!

Canon responded so I guess the ball is in their court. Canon won't say anything until they are absolutely ready. Nothing worse than jumping the gun and shooting yourself in the foot. My guess if  this is a firmware fix they feel they have time because that upcoming update is not scheduled for a few months I think.          

I'm hoping that this isn't just left... We've provided info as asked, regarding shooting conditions, and equipment used. I keep checking back here, but no new news 😞 When/How are we going to hear about any further update? Will this problem be address with the April fireware update?

Somebody, anybody, please.... we are going crazy here!

The Canon engagment in this forum regarding this problem is most disapointing.  The expression 'actions speak louder than words' comes to mind, which basically says precisely nothing has happened on this topic.  in the world where major electronics companies host  forums and participate in collecting information assisting the customer base, this is the worst behavior of any official company representation II have every seen.  Canon you know that you can turn this around instantly.  All it takes is for someone to provide something meaninginfu here;  You will need to provide more than just a new representitive every several weeks who pops in here to say  the same thing but provides nothing, before disapearing back into the shadows. 

Hi all, we have an important update on this topic. Thanks again for your feedback on our Forum.


Canon has confirmed that, depending upon the shooting conditions, it may take slightly longer for the EOS 5D Mark III and EOS-1D X digital SLR cameras to acquire focus when using the Speedlite's AF Assist Beam, compared with that of the EOS 5D Mark II and EOS-1D Mark IV digital SLR cameras using the Speedlite's AF Assist Beam. We are developing a firmware update to enhance the focusing feature for the EOS 5D Mark III and the EOS-1D X. The schedule for release of this firmware update will be announced shortly.


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