40mm F2.8 Pancake Full-Time-Manual Focus?

In the manual it says when on 'One Shot AF, focus manually by pressing the shutter button 1/2 way and turning the focus ring (Full-Time-Manual Focusing)'

Do they mean
1.press it 1/2 way, wait till it focuses then release and then turn the focus ring
or
2.press it 1/2 way, wait till it focuses then keep holding it down and then turn the focus ring

and
3. Do you have to wait until it focuses before moving the focus ring. NB I added the wait till it focuses because on Sony cameras its essential that focus has locked before you can 'over-ride the focus system manually' If you don't get a focus lock you damage the af system of the lens/camera or both.

I assumed this was similar on the pancake because under the warning section (! - to prevent lens or camera malfunction or damage) it says " do not touch the front rotating parts of the lens while autofocus is active"

So I am assuming it's half press wait till you get focus lock, then manually overide by turning the focus ring WHILST keeping the shutter button permenantly 1/2 depressed (i.e. locking it focused so it doesn't start refocusing)

Particularly interested in anyone who has checked this out with Canon Prof Services I tried but got someone who knew less than me! i.e. never seen one.

Submariner wrote in post #14696686
So I am assuming it's half press wait till you get focus lock, then manually overide by turning the focus ring WHILST keeping the shutter button permanently 1/2 depressed (i.e. locking it focused so it doesn't start refocusing)

Yep, half pressing the shutter button and holding it will allow you to manually tweak the focus after the AF has done its thing.
If the lens in set to MF then of course you have full time manual focus.
If you use the back button for AF then full time manual focus is available at all times, without having to hold or press anything.

The focusing ring doesn't actually rote when using AF

dave_bass5 wrote in post #14696865
Yep, half pressing the shutter button and holding it will allow you to manually tweak the focus after the AF has done its thing.
If the lens in set to MF then of course you have full time manual focus.
If you use the back button for AF then full time manual focus is available at all times, without having to hold or press anything.

The focusing ring doesn't actually rote when using AF

Thanks Dave always good to check - appreciated

The way One Shot works is that it performs the focusing, then stops once it's locked on. It remains there so long as you maintain half-press on the shutter button. If you want to refocus with AF, you have to release pressure on the button, then re-apply it. If you want to override it manually, you can do so once AF has stopped.

You just want to let the lens complete focusing and stop, before overriding it with FTM. It's interesting that you have to be careful to keep from touching the focus ring on the lens during AF. That means the lens is not "fly by wire", that it's mechanically moving the focus ring during AF.

Not all lenses are FTM capable. But it sounds as if the 40mm is (I don't have that specific lens... yet.)

As a general rule, USM lenses are FTM capable and micro motor lenses should not be overridden manually without first turing off the AF at the switch on the lens, or you might damage the lens. The 40mm is a new breed of lens, with that STM focus drive. So the statement in the manual indicates it is FTM capable.

You can't normally do FTM in AI Servo because the lens focuses continously and will override you overriding the initial focusing effort.

However, since Dave mentioned Back Button Focusing... using that technique does allow FTM in either One Shot or AI Servo. When using BBF, all you have to do to stop AF is lift thumb pressure off the button. Then it's effectively the same as One Shot, for purposes of FTM (among other things).

Good info but as I said, the focus ring doesn't move when AF is in use and the lens is definitely focus by wire.
I tried turning the focus ring Whiel the AF was working and it didn't really do anything, including not breaking lol.

dave_bass5 wrote in post #14697594
Good info but as I said, the focus ring doesn't move when AF is in use and the lens is definitely focus by wire.
I tried turning the focus ring Whiel the AF was working and it didn't really do anything, including not breaking lol.

Hopefully not!

amfoto1 wrote in post #14696980
It's interesting that you have to be careful to keep from touching the focus ring on the lens during AF. That means the lens is not "fly by wire", that it's mechanically moving the focus ring during AF.

What are you basing this statement on? Everything I have read says the focus ring on the EF 40mm does not move during AF.

msowsun wrote in post #14699284
What are you basing this statement on? Everything I have read says the focus ring on the EF 40mm does not move during AF.

Actualy I think the manual is referring to the zoom bit coming out, and thats the bit not to touch.
Verbatum from manual " do not touch the front rotating parts of the lens while autofocus is active"

Everyone who has handled this lens said there are no "rotating parts".

The EF 50mm 1.8 II DOES have a rotating focus ring during AF and it's manual has basically the same warning. I guess someone at Canon screwed up.

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