which button for continueous AF

[SPORTshot]

I've seen in other threads (but can't find them) where you can set up the AF to be controlled by your thumb, instead of pressing the shutter button down half way. If I remember correctly this will allow you to shoot with continueous AF.....can someone help with instructions on how to do this or tell me what section of the manual to look in, PLEASE ! I've searched the manual but I must be blind and I apologize.

[40Dude6aedyk]

If your camera has an AF ON button, then press it. Surprisingly, it turns on AF. You don't have to set up anything special to do this. It always does this. Set your AF drive to AI Servo as well.

[SPORTshot]

If your camera has an AF ON button, then press it. Surprisingly, it turns on AF. You don't have to set up anything special to do this. It always does this. Set your AF drive to AI Servo as well.


Thank you 40Dude..... I understand the AF button, but I thought that there was a way to use your thumb on a button on the back (the * button comes to mind) that you can keep pressed down while shooting to keep the AF tracking as you take pics....Or do you just hold down the AF button ?

[DDCSD]

What camera are you using SPOTshot?

[SPORTshot]

What camera are you using SPOTshot?


50D, sorry about not including that needed info.

[40Dude6aedyk]

On newer Canon dSLR cameras, there is an AF-ON button on the back that you can hold down with your thumb, when you do that and AF drive mode is AI Servo, then it should continuously auto-focus if you have the AF-ON button pressed at all or the shutter-button pressed halfway. Try it in the comfort of your own home to see what I mean. Unfortunately there can be some confusion depending on which camera you have.

So the 50D has a button labelled AF-ON on the back, right? Press it with your thumb. What happens?

[DDCSD]

50D, sorry about not including that needed info.

Cfn IV-1

I usually use my cameras set to the equivalent of CfnIV-1-3 so that I can lock exposure with the shutter button and not be forced to AF.

I don't have a camera with the AF-on button, but I would still remove the AF from the shutter button if I did. I hate the AF activating every time I half-press the shutter button.

Another benefit is that you can use AI-Servo like One-Shot AF.

[SPORTshot]

Ok, I held the AF-ON button down and it worked....thanks 40Dude. I must not have pushed it all the way in the first time around. Yeah, I'm an idiot !

[DDCSD]

Ok, I held the AF-ON button down and it worked....thanks 40Dude. I must not have pushed it all the way in the first time around. Yeah, I'm an idiot !

Read my above post. I think you could benefit by taking the AF off of the shutter button. It takes a bit of getting used to, but it is worth it.

[SPORTshot]

Thank you DDCSD !

[40Dude6aedyk]

DDCSD has given great advice. The custom function is to REMOVE auto-focussing from the shutter button. That CF function does NOT put AF-start or AF-ON on the back of your camera since it was already there in the first place.

I use manual exposure (M mode), so that the shutter button does not do any exposure metering as well. And I have set the custom function so the shutter button does not affect auto-focus either. All my shutter button does is release the shutton. This means that I can hand my camera to anyone and they will take terrible OOF pictures because the camera does not work like they expect it to.

There are many long threads in this forum about putting the focus button on the back of the camera. That is for older cameras. Canon added the AF-ON to the back of the camera, so this doesn't have to be done anymore.

[dmwierz]

putting the focus button on the back of the camera. That is for older cameras. Canon added the AF-ON to the back of the camera, so this doesn't have to be done anymore.

Is this right? My "old" MkIIn still has to be told to move the AF to the* button, so if this has been added, it's only been done on the last couple years.

[DDCSD]

DDCSD has given great advice. The custom function is to REMOVE auto-focussing from the shutter button. That CF function does NOT put AF-start or AF-ON on the back of your camera since it was already there in the first place.

I use manual exposure (M mode), so that the shutter button does not do any exposure metering as well. And I have set the custom function so the shutter button does not affect auto-focus either. All my shutter button does is release the shutton. This means that I can hand my camera to anyone and they will take terrible OOF pictures because the camera does not work like they expect it to.

There are many long threads in this forum about putting the focus button on the back of the camera. That is for older cameras. Canon added the AF-ON to the back of the camera, so this doesn't have to be done anymore.


I'm fairly certain that it will still make the * button start AF, along with the AF-On button. From what I have read, many people prefer to use the * button over the AF-On button for comfort reasons.

[40Dude6aedyk]

If you don't have an AF-ON button on the back to work with, THEN you gotta do something different because you ain't got no AF-ON button on the back to press. This also might be the case if you use a grip with no AF-ON button. In this case, one can make the * button (AE lock) take on the function of AF-ON. Also on a 40D, you can switch the AF-ON and * button functions with C.FnIV-2-1. (Remember it's C.FnIV-1-2 that removes auto-focussing start from the shutter button; this C.Fn does not change the * button function. See Derek's attached figure in this thread of the manual info for BOTH these custom functions, so you don't confuse the two different custom functions.)

I think folks with cameras with AF-ON buttons (e.g. 40D, 50D) don't need to switch the functions of the AF-ON and * buttons unless they have incredibly small hands or short thumbs or use a grip (these are DDCSD's comfort reasons). Also in Manual mode, AE-LOCK is meaningless because you already have "locked" the exposure at whatever manual settings you have selected.

So if you have both an AF-ON button and a * button, it wouldn't hurt to be pressing them with your thumb to see what they do. :) And reading your camera manual doesn't hurt either, but there may be comfort reasons not to read the manual as well. :)

[theshape]

And reading your camera manual doesn't hurt either, but there may be comfort reasons not to read the manual as well

Bwahahaha!

[canonnoob]

nevermind.. im an idiot...