Back Button Focus

I was watching yet another dog photography video yesterday, and in one of the comments, someone asked why the instructor didn't talk about 'back button focus'.  I don't remember what the instructor's response was (if any), but I was curious about back button focus, and since you can find anything on Google, I Googled it, and came up with an answer.  Here's an article about it from the Digital Photography School, but here's my explanation: In the standard set-up of a DSLR camera, assuming you aren't using the manual focus setting, you push the shutter release button halfway down to focus the camera and then push it all the way down to actually take the picture.  This is all fine and dandy, but for a couple of things; if you use the 'multi-point' auto-focus, the camera may pick something other than what you want to focus on (this has happened to me more than once), if you use the 'center point' auto-focus (which is what I usually use) and I want to focus on the dog's eyes, it is tough to get the entire dog head in the photo if the eyes are the center of the photo - and if you move the camera, it will refocus on the new center point.  With back button focus, you assign a button on the back of the camera to be the focus button, and the shutter release button just releases the shutter and doesn't deal with focusing.   

It all sounded interesting, if a bit complicated.  I thought I'd try it out with some portraits.  Since I am still playing around with the big aperture of the 50mm lens (and hence a very shallow depth-of-field, making focus on a specific point even more important), I thought I'd see if I could get some big aperture portraits of the girls.  They were sleepy, so they weren't moving much.

This is probably my favorite photo of the day, if not possibly the week.  You'll notice that her eyes are in focus, but with the shallow depth-of-field, even the tip of her nose is not in focus.  It really draws you attention to her eyes.  Very cool.

Abby's eyes were not the center of the picture, and yet they are in focus.  So cool!

The girls were snoozing, so I thought I'd get a few photos of them.  I think the shallow depth-of-field gives a muzzy, sleepy feel to the shots (which is what I was going for).

Because of the wide aperture, you can really see how focusing on the eyes and then moving the camera to get the shot I want works - I don't have to have Abby's eyes in the center of the picture, and I don't have to hope the multi-point focus mode actually picks the eyes to focus on.

I was playing around in the studio, so I thought I'd try a few photos here, too.  Given that I was using a flash, I had a fairly small aperture, but I still liked the idea of being able to focus on the eyes, and then 'composing' the picture.  

Drama-doodle.

Eyes?  You wanna see my eyes?!?  Heehee.

I was curious, however, as to how this back button focus thing would work with the action photos since, as far as I can tell, if you want the camera to keep focusing on a moving object (which I do) you have to keep the back button pressed while you release the shutter.  Not being the most coordinated person in the world, I wasn't sure how well this was going to work, but I was game to give it a shot.

Surprisingly, it worked out fairly well.

In taking running shots, I usually have some lag between the focus and the shutter release, while I still have some lag with the back button focus method, there seems to be less lag with the focusing, so I have more in-focus shots - assuming my finger doesn't slip off the button in the back, which did happen...

This is a case of less lag than usual - when I usually get these photos  (Fi lunging toward me to get the ball) the grass is the focal point 99% of the time...

And since I was outside, I thought I'd try a few more portraits.  These pictures could probably have benefited from my little reflector, but I didn't want to complicate things more than I already was.

  
The early verdict is that while the back button focus method is a bit more complicated, I am very pleased with the early results.  The video I watched on it suggested trying it for a few weeks to become really comfortable with it, so I'll keep playing with it.  I definitely like it for portraits, where I always want the eyes in focus.

Day 263/365.