Africa Wild

Back Button Focusing.

Most DSLRs have an option to use the back button to auto-focus instead of using the half-pressed shutter release button. This is an option which was pointed out to me by Dewi and after trying it, I wouldn't go back to the old way.

If memory serves (which it often doesn't) the back button has to be switched to AF-ON and the shutter release button has to be set to Shutter Only. The best way to configure this is to Google Back Button Auto-focus for your specific camera.

Back button focusing can be useful if you have a bird that keeps returning to the same perch, or - as below - a parent bird returning to feed a chick.

In this case, I focused on the chick and waited for the parent bird to enter the viewfinder then I pressed the shutter release which just took the picture instead of focusing first, then taking the picture.




Back Button Focusing can also be useful for recomposing your picture without mucking around moving your focus points. Just focus using the middle focus point, then compose the picture and press the shutter release.

Holding down the back button and keeping the focus point on the subject will activate continuous focus mode for moving subjects. This can be tricky as focus will be lost if the focus point moves off the subject. There is a setting on the camera to adjust the time delay before the camera tries to refocus but this is meant to cater for objects coming between the subject and the camera.

There is a very good video clip which explains the various focusing modes on a DSLR here.

thank you blue tuna for posting this article....

i cannot wait to try it out

BBF can take a little getting used to. It took a few minutes when I first tried it and the next couple of times I used the camera, I wondered why it wasn't focusing for a second or two. It's second nature now.

Nice one BT. Glad you tried it out and now prefer this method. I was amazed when I first used it myself.

Trouble is, I have one body set up for back focusing, so when I use the second body (landscapes, portraits etc.) I automatically try to focus with my thumb now.

Nice pics by the way.

I fully agree. I think the best thing about it is the fact that you effectively have both continuous and single-shot focus turned on at the same time, you choose when to focus instead of the camera doing it for you.

The only issue is that on the low-to-mid-range cameras, there is only one button on the back, thus you lose AE/L functionality. However, if you want to use this, you can set it up either on one of the front buttons (For Nikon users Fn or DOF Preview), or even on the shutter button itself.

Do all DSLR's have this function?

I think most of them do. I seem to remember that you use a 600D(t3i)?

https://www.youtube.com/watch?v=pEBsfZx-NbU

No BT, I have the 1000d. I tried looking up back-focusing for it but couldn't find anything. The Brat has the 700d which is a lot newer than mine, maybe he can do it.

have canon
but will try to reproduce what you showed

You should be able to do back-focusing on all DSLR's...well maybe only speaking for Canon. But bear in mind it does not work when in auto mode....:)