5d3 ai servo mode HELP!!!!

[CANONPRO123]

Hey everyone, i just went for a walk with my wife... tried taking pics of her walking towards me using ai servo... it kept misfocusing... any help would be great!!!

 

[RyanDavis200]

You're obviously not a Canon Pro, like your name states.
Are you shooting in a dark room with a $300 lens with all of the focus points turned on? That might be your issue. Try the single center focus point, a quality lens that's meant to be dead on with AI ($1,000+) in a lit room and you should be good to go.

 

[CANONPRO123]

I was using center focus point with cross types activated... but since your sooooo amazing, I actually was shooting with a 70-200mm 2.8L is ii... so thanks for the advice...

 

[RyanDavis200]

Not suggesting I'm amazing, but you're saying the AI Servo doesn't work right. Yet provide no info, samples, setup, etc.

The autofocus system is better than the version in their top of the line pro sports camera that shoots AI Servo focused images you see on the cover of Sports Illustrated and other magazines. So if you're suggesting there is an issue I would suggest (kindly) that you post samples with your settings so people can help.

 

[Ryant]

Hey Canon pro, I also have had some issues and I am still working it out. It takes some playing around with I have found. The descriptions in the camera menus are only partially helpful. Also you can press the rate button in the af points menu to modify the different focus cases manually. I found I needed to keep testing each mode to find something useful. I ended up landing with mode 2 as the best for what I tested with.

1. Go to menu AF:1 and set it to case 2
2. Set both options to focus priority in menu AF:2 (one menu over)

My lens settings:
Lens Canon 50 1.4
Set to F2.0 and 1/200 at iso 1600

Also according to the manual (which we should all read!) It says the more af points you have selected the easier it will focus. It mentions the point of using only one af point in the center is to focus through something like the bars of a cage at the zoo (canons description). There are two af center points the small square and the big one. I picked expanded so it had the center and one af point to each side up, down and sideways.

I also tossed in a few shots of my cat using this mode. Its not 100% perfect but its near enough if your not pixel peeping.

https://plus.google.com/photos/106912844660193230002/albums/5725580684836636401?authkey=CL-UvpL6w9_Mew

 

[Dianoda]

I was using center focus point with cross types activated... but since your sooooo amazing, I actually was shooting with a 70-200mm 2.8L is ii... so thanks for the advice...

Honestly, this is one of those situations where, based on the information you've provided (ie, almost zero), the best advice I can give is to sit down, read the manual, and test the various settings/functions in a controlled environment - the AF system of the 5D3 is rather complex and it's worth your time to at least read that section of the manual in detail. If you still have trouble after that, seek help and post as much detail about your camera settings and the nature of the issues you encounter as you can - for example, camera mode (ie, P/A/S/M), shutter speed, aperture, focal length, IS on/off, ISO, detailed full AF settings, maybe series of bursts shot in high speed drive mode, etc.

Also, from a usability standpoint, I suggest remapping AF to the AF-on button and disabling it from the shutter half press (switch shutter half press to metering start versus metering and AF start - you should be able to access this submenu using the Q button and selecting custom controls) - try it, you'll probably love it, and if not, at least you'll know the option to decouple AF from the shutter half press exists, and how to do it. Good luck!