Focusing Tip - Canon 7D: Just found this tip for using the AF back button to lock focus on the 7D. In conjunction with that they suggested using AI SERVO mode regularly instead of ONE...

gemlenz Loc: Gilbert Arizona

Just found this tip for using the AF back button to lock focus on the 7D. In conjunction with that they suggested using AI SERVO mode regularly instead of ONE SHOT. It's a little awkward at first, but I think after I get used to it that may be a good way to go to improve sharpness. I also started using 9 focus points instead of single focus point. That way I can get more of my subject in focus.

What do you guys think about this tip? I assume other hi-end DSLRs have a similar capability.

wtw2143 Loc: West Hempstead, NY

You did not mention where you got this tip from; I use the back button on my 7D for AF on all the time, try this link on the web, for more in depth explanation of AF, Tack sharp & AI Servo on 7D.

http://digital-photography-school.com/advanced-tips-for-tack-sharp-images

Hope this helps....

gemlenz Loc: Gilbert Arizona

wtw...I notice with mine though I have to hold down the AF-on button.otherwise when I press the shutter it re-focuses. I thought it was one or the other when you have this set and that shutter button would not re-focus. Am I doing something wrong?

BrianHanna Loc: Pittsburgh

Where you turned the back focus button on, you have to adjust the settings for the shutter button to turn it off.

jimberton Loc: Michigan's Upper Peninsula

You need to go to menu...10th icon over and make this setting

Custom Function IV/Operation Others...1 Custom Controls

AF-On needs to be set to AF

oldtool2 Loc: South Jersey

gemlenz wrote:

Just found this tip for using the AF back button to lock focus on the 7D. In conjunction with that they suggested using AI SERVO mode regularly instead of ONE SHOT. It's a little awkward at first, but I think after I get used to it that may be a good way to go to improve sharpness. I also started using 9 focus points instead of single focus point. That way I can get more of my subject in focus.

What do you guys think about this tip? I assume other hi-end DSLRs have a similar capability.

Some do, some don't. The 7D camera body is a great body for shooting any kind of action, from sports to nature and wildlife.

Here is a thread you need to read.

http://www.uglyhedgehog.com/t-39889-1.html

It not only explains back focus it explains the center point expanded focus feature and discusses both well. Take 5 minutes to read this thread before picking up your camera. Then go back and read it again with camera in hand to make the changes. You will learn how to set up center point expanded, back focus, how to switch which buttons to make it easier to use and how and why to use back focus. Some of the best nature shooters on UHH use this system.

These are two excellent features of the Canon 7D. I have my 7D body set up using these features and rarely change them. They make shooting action shots so much easier. I also use the back button focus on my 50D body. Unfortionatly the 50D does not have the center point expanded focus feature.

Jim D

photophly Loc: Old Bridge NJ

Very informative.......Thanx.

jeep_daddy Loc: Prescott AZ

gemlenz wrote:

Just found this tip for using the AF back button to lock focus on the 7D. In conjunction with that they suggested using AI SERVO mode regularly instead of ONE SHOT. It's a little awkward at first, but I think after I get used to it that may be a good way to go to improve sharpness. I also started using 9 focus points instead of single focus point. That way I can get more of my subject in focus.

What do you guys think about this tip? I assume other hi-end DSLRs have a similar capability.

Using these settings might be ok for the photography you are doing now but I couldn't say it's good for all photography. The only real advantage to BB focus is in IA Servo you can move with the subject and keep the BB focus pressed while you start or stop shooting as needed. You can do this with the shutter button too but a lot of people release the button and have to repress it half way down to acquire focus lock again. One Shot focus has the ability to let you focus and then recompose your shot. You can't do that with AI servo. I never use 9 focus points because you are still relying on one of nine points to decide where to focus on the subject. I'd rather choose the one spot I want' in focus. This is especially important if you shoot wide open for shallow DOF. You should try it and decide for yourself.

Swamp Gator Loc: Coastal South Carolina

gemlenz wrote:

Just found this tip for using the AF back button to lock focus on the 7D. In conjunction with that they suggested using AI SERVO mode regularly instead of ONE SHOT. It's a little awkward at first, but I think after I get used to it that may be a good way to go to improve sharpness. I also started using 9 focus points instead of single focus point. That way I can get more of my subject in focus.

What do you guys think about this tip? I assume other hi-end DSLRs have a similar capability.

I have been using BBF going back to the 90s using an
EOS-1n film body.
Except on the 7D (as well as my 30D and 50D) I don't use the AF On button for AF, I use the * button.

pamelajoy Loc: Aussie

oldtool2 wrote:

quote=gemlenz Just found this tip for using the A... (show quote)

I don't think the 60D has expanded centre point focus. does anyone know. I'm still finding my way around my camera.

Jer Loc: Mesa, Arizona

I just started using the AF back button last week at a football game. I was told that just about all the pros use it. Getting use to it will take time but I really see the advantages. It reduced my out of focus shots.

gemlenz Loc: Gilbert Arizona

Ok I got the AF-on button doing the focus lock and not the shutter bitton. The one thing I notice now is that when you use AI-Servo you don't get the beep when focus is achieved. Is that normal?

wtw2143 Loc: West Hempstead, NY

gemlenz wrote:

Ok I got the AF-on button doing the focus lock and not the shutter bitton. The one thing I notice now is that when you use AI-Servo you don't get the beep when focus is achieved. Is that normal?

Yes, it's normal. AI servo there is no beep.
Using AI-Servo on a moving subject - the focus never actually "locks" . Besides, it wouldnt make any sense because it is essentially constantly moving the focus plane and would result in multiple beeps or one long one. Think about it.....

gemlenz Loc: Gilbert Arizona

makes sense WTW...I'm going to have to play with it and see the results....btw...I also had to reset my C1,C2 and C3 default settings...thx.

gemlenz Loc: Gilbert Arizona

Just went out to the park and used my BBF with Ai-servo while photographing some ducks and kid riding bikes. Wish I had discovered this before. It's amazing how it improved my focusing with moving subjects and made it alot easier to "get the shot". thx all for your help. This site is great! I'll try to post some of the more memorable shots.