Something that has become very popular over the recent years is back button focus (bbf). What is it I hear you ask.
Back button focus allows you to focus and shoot, without the chance of accidentally re-focusing and ruining your shot. Find out how to use it.
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Focusing and Shooting with One Button
Well, let’s start by looking at your camera, which is likely to be a DSLR or mirrorless. When you first use your camera, the focus is set to the shutter (halfway) release button.
Unless you have changed it, you focus and photograph with the same button. A press of the shutter release button half way gets the focus, a full-press captures the moment.
If you are yet to buy a camera, have a look at our article on DSLR Vs. Mirrorless cameras here. Canon and Nikon DSLRs have many great features for shooting and focusing.
There are very clear benefits to this system as both tools are in one button. When you take a photograph, you typically focus and then photograph straight after.
One fluid movement. The problem with this system is that you need to keep your finger pressed on the focus until you capture the image.
If there is a big gap between focusing and capturing, it can be annoying. The bigger problem is what if you don’t want to keep re-focusing after that initial auto-focus.
This above system will re-focus every time you take a picture. If your subject isn’t moving towards or away from you, you don’t need to refocus. A great tip for that single point of focus.
This order takes away time from photographing which means you might miss some fast sports moment. One fix to this system is to focus and then switch your lens to manual.
This bypasses the shutter release into not refocusing but only capturing. The nice thing about this is that your camera’s viewfinder will blink red to let you know you are still in focus.
This is not such a great alternative as you can’t move, re-frame and switch your camera back into Autofocus fast. You might forget you are not focusing at all, and the series of images are unusable.
What else can be done?
Well, you can use AI Servo mode, as that follows people and other moving subjects. Again, this is tricky to work with. The manual focus needs a lot of practice.
AI Servo is great for when your subject moves. You keep your finger pressed on the shutter button halfway which is the AF (Autofocus) button. This helps you find the focus point.
It offers you a continuous focus, even when using live view. For low light conditions, it will be difficult to capture fast-moving subjects. Out of many images, you might find one shot worth using.
What Is Back Button Focus
Ok, so we know that the back buttons refer to the buttons on the back of the DSLR. But what is what is back button focusing?
Back button focusing means changing your focus button to a different button. You reassign a button on the back of your camera to do the focusing.
Back button focus might seem like a strange concept, but only because you are so used to the standard idea.
When I first came across this idea, I thought it was complicated and I wouldn’t get used to it. Boy, was I wrong.
Whenever I start a photographic street tour, the first two questions I ask are How well do you know your camera? and Do you use back button focus?
When it comes to helping people with their photography, these are the two most important questions.
Ok, so we re-assign a button to focus with. Why use back button focus?
Back focusing or back button focus could be the difference between a well focused shot, or a blurred one.
Having the focus button on the back of the camera means no more auto-refocusing. I can focus using my thumb, while my index finger rests on the shutter release button.
This system is faster for my photography and workflow. Here, I can use both appendages in rapid succession whereas the standard system has to wait for me to focus to capture the image.
I only wish I had discovered this back button focus system a long time ago. It really saves time and I don’t need to worry about not getting that shot due to refocusing.
For my Canon, back button focusing was a game changer. For those Nikon cameras, the AF/AE lock can be configured as a lock focus button.
How to Set-Up Back Button Focus
Usually, the button you want to reassign for back button focus is near the top right-hand corner of the back of your camera.
This is because as you grip your camera in your right hand, you still only want to use one hand. You need the other one to concentrate on other things.
On a Canon 7D (what I use), I have reassigned the AF-ON button to focus the lens. The AF-ON button usually changes the autofocus from single shot to continuous focusing.
This is something I do not really use, as I do not find my self-switching from static subjects to fast-moving ones that often.
If I want to change this, I can still do so in the ‘Q’ functions menu easily. Now I can change my back button autofocus easily if I don’t need it.
Start from the screen as follows (‘Q’ Mode)
Press the Menu button on the left-hand side of the camera.
Move along to custom functions. This has a red symbol of a camera and five lines underneath it.
Go to C.FnIV: Operation/Others and select option 1. This is indicated by the star in the bottom left-hand corner.
A new menu custom control will pop up. Move to the AF-ON button. Enter the next step by pressing ‘set’.
Select Metering and AF start, which is the first icon.
Press ‘set’ to assign the button as Autofocus. It will bring you back to the Custom Control menu. Press menu twice to go back to the original screen.
Other Canon cameras back button focus work as follows:
EOS Rebel T3/ T3i/T4i: C.Fn 7 (option 1 or 3)
EOS 50D/60D: C.Fn IV-1 (option 2 or 3)
EOS-1D Mark IV: C.Fn IV-1 (option 2 or 3)
EOS 5D Mark II/Mark III/ EOS 1-D Mark IV: C.Fn IV-1 (option 2 or 3)
EOS-1D X: C.Fn menu screen 5 (Custom Controls — Shutter, AF-ON, AEL buttons)
These are the guidelines for Nikon back button focus. In the camera menu, head to the custom setting menu (the option with a pencil icon).
Then, find the autofocus section.
Look for AF activation and select AF-On. Press OK to enable it.
For Nikon DSLRs without an AF-On button, you will need to reassign another button at the back of the camera to act as your makeshift AF-On.
Find the back button focus option under the Custom Settings menu and then the Controls section.
Choose Assign AE-L/AF-L button and scroll down to AF-On. Press OK.
After changing to this back button focus system, it might take a few photographs to get used to the new focus location. After this, you will find your workflow speed will be much faster. You will focus faster and you will not have to worry about re-focusing and missing opportunities.
If you would like more information regarding focus modes, see our article here.