Firmware upgrade for 5D Mark 3

[CanonNewbie]

Hi All,

This question is for the folks who use a 5d M3 along with a 600 ex rt flash.  Do you have issues with the auto focus being slow when the flash is connected?  Has anyone tried the firmware upgrade that came out in April to correct this issue and did it help?  I have been trying to find an answer to this but no luck.  I read mixed reviews about it, but could not tell what combination of camera & flash the users were referring to.  Wondering if I should do the upgrade or stick to the firmware I have.  Any advice would be appreciated!!

Thanks!!

[hsbn]

It's almost always good to update your firmware to the latest.

[CanonNewbie]

Thanks, but I've read that lots of people had issues with the upgrade, and were able to revert back to the old firmware.  The previous firmware is not available for DL any longer, which is why I wanted to hear from people who have done it and can share their results.

[TCampbell]

I'm not having any issues.

I have a 5D III with the latest firmware (1.2.1).  I tested this with one of my 600EX-RT units... put the lens deliberately well out of focus, then let the camera auto-focus and repeated this about 20 times.  It's pretty fast.

I swapped the 600 for a 580EX II and repeated the test.  While I'm not specifically using anything to time how long it takes, both of the focus-assist beams allow the camera to focus very quickly and I am unable to detect any difference in focus times between the two.

I should mention, however, that the 5D III has a pretty sophisticated system with lots and lots of options.  I used Zone AF and was using the focus points around the center (which tend to be the best.).  For grins, I also tried spot AF using the center point.  It was about the same speed.  I noticed one particular attempt where it paused just briefly while focusing...as though unsure.  In fairness... spot AF restricts the camera from using any focus assist points... it uses the narrowest possible area.  It's designed for situations where you want a point with particularly good contrast and detail but which is also very small.  E.g. if you wanted to lock focus on the iris of someone's eye but did NOT want the camera to be fooled into focus on their eyebrow you might use this mode.  But if the focus target lacks adequate contrast (and mine did) then it can take longer to focus (and this is NOT a defect... Canon documents how all this works and why you might choose one mode over another.)  

Where I was going with this... I suppose it's possible someone used an inappropriate focus mode (such as spot AF) and then chose an off-center point and had poor results.  You'd have to know EXACTLY what they were doing... the focus mode; which AF point(s) they chose; what they were using as a focus target (ideally you'd use a target specifically designed for focus tests -- they have LOTS of detail and contrast.)

In any case... I can't notice any issues with the firmware, the 600EX-RT, nor even a difference between the performance of a 580EX II vs. the 600EX-RT.

[CanonNewbie]

Thank you for the detailed response!!

Well, I keep it on the center focus - and one shot focus mode.  And focus and recompose as necessary.  Maybe I'll try the zone focus around the center instead and see if that helps me. 

[CanonNewbie]

Little update.  I did the upgrade and tried it this past weekend at a reception.  The dance floor is where I struggled the most.  There def. was an improvement with the AF assist beam with the upgrade, but still struggled at times. Tested another photographers 580ex flash, and with that I was able to take the photos much faster and those were also more in focus.