GX1 back button focus?

panyuser · #1 January 26th, 2012, 02:53 AM

I like setting my D5000 to back button focus:

- the rear AE/AF button is an "AF on" button, making it focus as I hold it down. (AFF is especially useful here.)
- the shutter button doesn't focus, but does lock exposure when pressed half way

I can't seem to achieve this with the GX1: I can get the focusing decoupled from the shutter button, but then I have no way of locking exposure when in P/A/S modes.

Is there something I've overlooked in the menus, or some other way of achieving something like this that I don't realise?

meyerweb · #2 January 26th, 2012, 07:00 AM

Not sure about the GX1, but with the GH2 if you set the rear button to lock AF only, the shutter release button still locks exposure when you press it half way.

panyuser · #3 January 26th, 2012, 08:23 AM

Annoyingly, once I lock the exposure, the rear AF button stops functioning (or seems to anyway).

Ned · #4 January 26th, 2012, 09:22 AM

Sorry I can only help with setting up back-button focus on the Olympus cameras... xP This is the only way I use AF on my cameras. I'm sure somebody will know how to do it on the Pannys.

timallenphoto · #5 January 26th, 2012, 02:47 PM

Quote:

Originally Posted by Ned

Sorry I can only help with setting up back-button focus on the Olympus cameras... xP This is the only way I use AF on my cameras. I'm sure somebody will know how to do it on the Pannys.

Is it possible to do on E-PL2 Ned??

Ned · #6 January 26th, 2012, 04:28 PM

Quote:

Originally Posted by timallenphoto

Is it possible to do on E-PL2 Ned??

Very much so.

First go to Sprockets => Button/Dial => AEL/AFL, and turn C-AF and MF (or whatever modes you want to use, but I'll explain my choices later) to Mode 3. Next go to Sprockets => Button/Dial => Button Function, and assign whatever button you want to be your back button (ie, like the big red record button or a Fn button) to "AEL/AFL". That will now be your AF button. :)

Now all you have to do is turn your camera to MF for single-AF or to C-AF for continuous-AF using the back-button. Of course, you could also change S-AF to Mode 3 instead of MF, but I prefer to use MF because it adds the S-AF function to your MF mode without taking away any of your MF functions. Then I still have S-AF as normal in case I want to return to the half-press of the shutter (ie, like when handing the camera off to somebody else to use). If you switch to C-AF while on Mode 3, then holding down your back-button will keep continuous AF.

This will work on any Olympus camera I've tried, from E-System DSLRs to PEN System cameras. :) The difference is that on most E-System DSLRs the assignment of the AEL/AFL button is already marked on a dedicated button. You can use that as your back-button, or swap with the Fn button using the "Fn Button Swap" feature (better for those with shorter fingers).

meyerweb · #7 January 26th, 2012, 04:57 PM

Quote:

Originally Posted by panyuser

Annoyingly, once I lock the exposure, the rear AF button stops functioning (or seems to anyway).

You're right. I guess I hadn't noticed because I normally lock focus first and then exposure, but I can see situations where that might not be ideal.

fredlong · #8 January 26th, 2012, 05:02 PM

Quote:

Originally Posted by panyuser

Annoyingly, once I lock the exposure, the rear AF button stops functioning (or seems to anyway).

It's the same on my G2. You have to lock the focus. Then a half press on the shutter release will lock the exposure. If I half press the shutter release first both are locked.

Fred

panyuser · #9 January 26th, 2012, 05:51 PM

Quote:

Originally Posted by meyerweb

You're right. I guess I hadn't noticed because I normally lock focus first and then exposure, but I can see situations where that might not be ideal.

But with this workflow, you have to recompose with locked focus. For closer work, this'll knock your focus out, won't it?

This seems like something they could easily fix with a firmware update; I have no idea why it would force the lock the way it is.

Ned · #10 January 26th, 2012, 06:24 PM

Quote:

Originally Posted by panyuser

But with this workflow, you have to recompose with locked focus. For closer work, this'll knock your focus out, won't it?

This seems like something they could easily fix with a firmware update; I have no idea why it would force the lock the way it is.

I don't see why they would do that either. With the Olympus system you can lock focus with the back button whenever you want, and lock exposure with the half-press of the shutter whenever you want. Full control of both aspects.