Back Button Autofocus With A Fuji X-T1

This is a 100% crop of the image below.  Just another reason I love Fuji lenses! (click to enlarge)

Fuji X-T1, 50-140mm f/2.8 lens @ 115mm; 1/40th sec. @ f/8; ISO 400

When I primarily used Nikon digital SLR cameras, I had gotten used to using what is called "back button autofocus."  If you are not familiar with that term, I'll explain it.

To me, back button autofocus is the best of all focusing worlds.  In a nutshell, It separates the function of focusing from the function of pressing the shutter button.  Instead of the camera focusing when you depress your shutter button halfway, pressing the AF-L button (on the Fuji X-T1, AF-On on the Nikons) on the back of the camera causes the lens to autofocus.  Now, here is the best part.  

If you set your camera (again specifically referring to the X-T1, in this case) in Menu 1; AUTOFOCUS SETTING; INSTANT AF SETTING to AF-C instead of AF-S, Then set your Autofocus selection switch on the front of the camera to "M", you can achieve back button autofocus.  By setting up your camera this way, you have all three focus modes, AF-S, AF-C and Manual, instantly at your disposal.  No need to change any settings or switches to change focusing modes.

First Example; Photographing with which you would use AF-S Mode

If you have a static subject, one with which you would normally focus in AF-S mode, you would half-press the shutter and hold it (to lock focus and exposure values), then recompose if necessary before full depressing the shutter to make the image. With back button autofocus all you have to do is place your focusing rectangle over the subject you want in focus, press the AF-L button and release when focus is achieved.  The camera focuses and locks in.  When you release the AF-L button, the camera will not change focus as the front switch is set in the manual mode.  Now you can focus and recompose repeatedly without worry that the camera will refocus when pressing on the shutter button for every shot. You don't have focus, hold and recompose between each shot.  In other words, you press the button and release and if your subject doesn't move, you don't have to worry about refocusing again.  It would be the same as if you were photographing with an old manual focus lens and film camera.  Once you focus on a static subject, you don't have to worry about refocusing before each subsequent shot.

Second Example; Photographing when you would use AF-C Mode

If you have a moving subject, press and hold the AF-L button and your camera will continuously focus on the subject as you follow it in the viewfinder.  Just hold the button in while tracking your subject and press the shutter at the optimum time as you hold in the button.  Your camera stays focused on the subject as long as you hold the AF-L button in while you make multiple exposures. One aggravating thing is with Fuji (X-T1) cameras on continuous focus, they still pulsate.  Try to ignore that.  Even though they do that, the lens always seems to be in focus when I press the shutter.  I've never seen that pulsating in any other camera, over multiple brands, and I have no idea why the Fuji engineers don't engineer that out.  As I said, it is aggravating to me.

Third Example; Photographing when you would use Manual Focusing Mode

If you want manual focus, just focus manually.  By not pressing the AF-L button, the camera just stays in manual focusing.  Nothing to switch or change.  Just don't press the AF-L button.  Your focus assist settings still take effect.  

Additionally, by using this method, your camera's shutter will fire a bit faster as the camera doesn't have to search for correct focus before each exposure and then release the shutter.

This is the entire frame of the image above (click to enlarge)

All of this being said, and I'll only speak for the X-T1 but other Fujifilm cameras may act in a similar manner, but this process is quirky compared to other camera systems I've used.  One additional bit of quirkiness, other than the pulsating, is that when pressing the AF-L button to focus (and having the camera set to manual focus), any focusing assist you have enabled will show.  For example, if you have the red highlights enabled, when the image is in focus, the red doesn't go away.  That, to me is again, distracting.  Personally, I use the standard method as the highlights in red, blue or white, are too distracting to me.  Your mileage may vary.

CAUTION:  Don't reset your camera to focus in this manner and then go out to photograph something important as you may not have gained sufficient muscle memory to engage this method when needing to photograph quickly and without having to think bout what needs to be done.  Practice, practice, practice.  Then when it is second nature, set your camera in this manner.

One other setting I have changed on my X-T1 is to swap the positions of the AF-L and AE-L buttons.  I find it more natural, when using my thumb to press a button for focusing, to use the button marked AE-L as its position feels in the right spot as opposed to being almost directly under my grip.  There is a menu item that allows you to swap their functions.

If you haven't tried this method, you may want to do so.  You may like it or it may not be for you.  I find it useful to have all three focusing modes available instantly to me instead of having to change switches, etc.  Additionally, I like my shutter button to be separate from my focusing function.

Thanks for looking. Enjoy! 

Dennis A. Mook 

All content on this blog is © 2013-2016 Dennis A. Mook. All Rights Reserved. Feel free to point to this blog from your website with full attribution. Permission may be granted for commercial use. Please contact Mr. Mook to discuss permission to reproduce the blog posts and/or images.