ID MKIII rear button focus problem

I recently converted to rear button focus after studying and following all the scripts and suggestion of which there is a bunch. Now that I have removed focus from the shutter button I loose AF when I take my thumb of from the * button before shooting. If I keep my thumb on the * while I depress the shutter button I get the red rectangle when I view the shot. If I remove my thumb then energize the shutter no red rectange or AF. Is this normal or is it something I've done in the configs?

RFDII wrote in post #13962957
I recently converted to rear button focus after studying and following all the scripts and suggestion of which there is a bunch. Now that I have removed focus from the shutter button I loose AF when I take my thumb of from the * button before shooting. If I keep my thumb on the * while I depress the shutter button I get the red rectangle when I view the shot. If I remove my thumb then energize the shutter no red rectange or AF. Is this normal or is it something I've done in the configs?

I see you're using the * button ( AE Lock button ) as opposed to the AF-On button to activate back button focus. It's not a problem if you prefer to use this as opposed to the AF-On button.

When you press the back button and acquire focus the red AF point ( red square ) will light up. If you keep your thumb on the button you are keeping track of your subject continuously. If you press the back button and then release it, you are effectively locking your focus. When you release the back button , the AF point display disappears. This is fine if your subject is still but if you are tracking a moving subject then you should keep that back button pressed. Does this help?

Here are a couple of links which may explain further:-

http://www.learn.usa.c​anon.com …ckbutton_af_art​icle.shtml

http://forums.dpreview​.com …age=39838524&ch​angemode=1


Keep enjoying your 1D3

What you describe by saying you lock focus by pressing the back button is the way I thought it worked also. In AIServo mode you receive no confirmation of focus at the time of shooting or prior to it. What I am describing by no red rectangle is when you display the photo after the shot on DPP or Breeze Browser and use the focus point display option. Even with a stationary object if you keep your thumb on the * button the red af rectangle will appear indicating AF was achieved when using DPP or BBP. If you first hit the * button to lock focus then remove your thumb the red AF rectangle will not display in post processing. If you first press the rear AF button of your choice then remove it before pressing the shutter button both products just display all the AF points and none of them show as having been active because they are still black. I know of no other way to confirm focus before or after.
Thank you for taking the time to help me with this.

Your Back Button technique is working correctly. You don't have any problem, other than being unfamiliar with it. Keep practicing.

In AI Servo, the focus never "locks"... it tracks and is constantly updated. You have to maintain pressure on the back button to keep it working. If following a moving subject and there is an obstruction, you can momentarily lift off the button to avoid refocusing on the obstruction, then reacquire by reapplying pressure once past the obstruction. The important thing is to keep your AF point solidly on the subject, at the point you want focus.

In One Shot you do get focus lock and can lift off pressure once that's achieved. Once One Shot achieves focus, it stops and remains there, even if you maintain pressure on the button. If you want to change focus, lift pressure off the button momentarily and then reapply pressure on the button to lock onto the new point of focus.

You do not get focus confirmation in AI Servo mode, whether using back button focus or not. The reason is that there is nothing to confirm... focus is constantly updating, predicting movement and changing as the subject moves. Even if the subject doesn't move, so long as you are in AI Servo there will be no focus confirmation.

In AI Servo, the moment you lift pressure, the camera stops focusing. So there is nothing to display in post processing. There is no active AF point. In One Shot, there is a point of focus that's maintained for some seconds after AF has locked on, so an active AF point will show in post processing (but only in Canon DPP or Zoombrowser, as far as I know).

You can use AI Servo as a default focus mode when using Back Button Focusing technique. Any time you want to stop focus, all you have to do is lift pressure off the button. But with AI Servo you do give up any form of focus confirmation and have to learn to trust yourself and the camera.

Switch to One Shot when you want greater accuracy, such as when using a really large aperture that's rendering shallow depth of field. It's still the more accurate of the two focus modes. Live View is even more accurate, though it's a lot slower.

RFDII wrote in post #13964053
What you describe by saying you lock focus by pressing the back button is the way I thought it worked also. In AIServo mode you receive no confirmation of focus at the time of shooting or prior to it. What I am describing by no red rectangle is when you display the photo after the shot on DPP or Breeze Browser and use the focus point display option. Even with a stationary object if you keep your thumb on the * button the red af rectangle will appear indicating AF was achieved when using DPP or BBP. If you first hit the * button to lock focus then remove your thumb the red AF rectangle will not display in post processing. If you first press the rear AF button of your choice then remove it before pressing the shutter button both products just display all the AF points and none of them show as having been active because they are still black. I know of no other way to confirm focus before or after.
Thank you for taking the time to help me with this.

My 7D works the same way. If in one shot focus you lift your thumb, no focus point will show in red in DPP. Seems like it should but it doesn't. I guess that is what Canon wanted, for some reason.

Alan/Yogi:
You can not believe the amount of material I have examined that doesn't say what is described in this thread. As Yogi mentioned my MarkIII didn't lock focus in one shot mode either based on lack of red rectangle in DPP or Breeze Browser.

On the MK 3 you have to change two settings, did you?

IV-1 is set to 2
IV-2 is set to 1