Back button Focus?

[momo3boys]

In another thread (I didn't want to highjack it), someone mentioned back button focus. I have searched for the term in the forum and in google and I can't seem to understand what you are talking about. Someone else in that thread asked the question too but it didn't get answered. Is it the button in the back that changes HOW you focus or is there a button that I don't have on my D200? (Yes I have read my manual, but it isn't memorizes yet).

 

[GeorgieGirl]

I have back button focus on my 7D...if I press it with my thumb it will focus as opposed to pressing the shutter half way with my index. Its ergonomic. It also can do more than that but that is one way it is used.

 

[MTVision]

You probably have an ae-l or af-l or ae-l/af-l button on the back of your camera. You can set the ae-l/af-l to lock exposure or focus. It would be in your camera menu where you assign functions. I don't have that camera so I'm not sure exactly. You would use that button (af-l) to focus and then use the shutter button to take the picture.

 

[GeorgieGirl]

She does...AF...I just looked it up.

 

[MTVision]

Actually right next to the wheel (on the back near right hand) should be a button that say af-on???? That is your BBF. Use that button to focus and the shutter to take the picture!

 

[brush]

If your camera works like my 60D, the custom settings let you choose how this button and your shutter control both the AF and Metering. I like setting it up so that this button sets my AF, but pressing the shutter halfway still does my metering. This way I lock my center AF point on what I want to focus on (subjects eyes, whatever) and then I'm free to compose the shot & meter for my exposure in my own sweet time without accidentally screwing up the focus. I've screwed up the focus a lot in the past before I learned you could use this button instead.

 

[Derrel]

Here's a relevant article. It is the AE-L AF-L button on your D200.

Nikon D200 Custom Menu: Autofocus

 

[ph0enix]

You probably have an ae-l or af-l or ae-l/af-l button on the back of your camera. You can set the ae-l/af-l to lock exposure or focus. It would be in your camera menu where you assign functions. I don't have that camera so I'm not sure exactly. You would use that button (af-l) to focus and then use the shutter button to take the picture.

The D200 has a AE-L/AF-L button

 

[MTVision]

The D200 has a AE-L/AF-L button:

Yep. But see that button right next to it called af-on? That is the button used for back button focusing

 

[ph0enix]

The D200 has a AE-L/AF-L button:

Yep. But see that button right next to it called af-on? That is the button used for back button focusing

I see. I was wondering what it was for.

 

[momo3boys]

Thank you everyone! I must have missed that in the manual. (my brain doesn't soak info up like it used to). I'm going to have to try playing with that tomorrow for sure!!

 

[MTVision]

Thank you everyone! I must have missed that in the manual. (my brain doesn't soak info up like it used to). I'm going to have to try playing with that tomorrow for sure!!

Go into the menu though and change the settings so that focus is only on that af-on button. Otherwise the shutter button will still allow focusing as well. It takes a little bit to get used to it and it will take even longer if the shutter button is still focusing as well! Once you get used to it - you'll like it.

 

[djacobox372]

You should find a setting in the menue called "af activation," this is where u can set it to af-on only. Its the only way to go, makes focus and recompose much easier

 

[Ms.Nash]

I have back button focus on my 7D...if I press it with my thumb it will focus as opposed to pressing the shutter half way with my index. Its ergonomic. It also can do more than that but that is one way it is used.

Cool- i learned something new today Ma!!! Georgie - Is it just for the ergonomics on the 7D for u? Do u this button another way yourself?

 

[Carny]

"makes focus and recompose much easier"

What is the advantage to this vs selecting a point that is on what you want? Is it because the center on most cameras is cross type? It seems like focusing then recomposing would cause you to lose focus, do you need to keep the movement to a minimum?