Written by Community Member Anthony Delia. More about his photography here.
“Tack Sharp” – a phrase that’s used to describe a picture where the main subject is clearly defined with a sharp focus and clean lines. If you’ve spent enough time around photographers, you’ve probably heard this term, or maybe you’ve seen some pictures that have a perfectly focused subject. It is also likely that you have some pictures that are slightly (or even very) out of focus — I know I do.
The method I’m about to explain to you may seem somewhat unconventional and take a little getting used to, but once you get comfortable with it you’ll be well on your way to achieving crisp, “Tack Sharp” pictures.
What is Back Button Focusing?
Before understanding what “Back Button Focusing” is, first you have to understand how your camera takes a picture with auto-focus.
There are two main actions of the shutter button. When you press the shutter button halfway, the camera’s auto-focus system quickly focuses on the subject. As you continue to press the button, the shutter is activated, and the picture is taken. There are some advantages of this: mainly the idea that you are only pressing one button to focus and take the picture. There are also some disadvantages to using the shutter button to focus and take the picture.
This article will explore the benefits of using Back Button Focusing in these instances. Simply put, Back Button Focusing separates the two actions of the shutter button and assigns the focus job to another button on the camera. Most cameras have a dedicated button for this action, usually on the back of the camera, but if your camera does not, you can usually assign another button to do the job in your camera settings. Now that you understand what Back Button Focusing is, let’s take a look at some of the benefits of using it.
Uses and Benefits of Back Button Focusing
Shoot with Auto Focus and Manual Focus at the Same Time
When shooting in single focus mode with the shutter button assigned to both focus and take the photo, you must press the shutter button halfway and then, at the right moment, fully press it to take the photo. The challenge with this method is, if you need or want to recompose, you must refocus as well. Similarly, if you are using the “Focus and Recompose” method, it is challenging to hold the shutter button halfway down as you recompose. With Back Button Focusing, you can focus using the dedicated button, recompose without having to hold down a button, and then shoot, shoot, shoot without having to worry about re-focusing. Your picture will still be in focus as long as you or your subject does not move.
In the portrait below, I used the “Focus and Recompose” method with Back Button Focusing to focus on the subject, achieve a good composition, and shoot continuously, only needing to refocus if I or the subject moved.
Shooting in Continuous Focus Mode
When you are trying to shoot a moving subject, i.e. small child or sporting event, you need to shoot in Continuous Focus mode. Without using Back Button Focusing, you would have to keep the shutter button pressed halfway while you try to track your subject and then fully press it to take the shot. If you use Back Button Focusing instead, you can hold the focus button down while you are shooting. The camera’s auto-focus system will continue to refocus as you are shooting the subject. I often shoot family photos with small children using this method.
Shooting families can be so rewarding, but they can also be very tricky. A lot of times, mobile little ones have a mind of their own. I have found that letting them do their thing and just capturing it can yield some of the best results. With my camera set to Continuous Focus and Back Button Focusing, I track the child(ren), while having the parents pose in the background or follow along, and snap away. As you can see in the pictures here, the results were perfectly focused photos.
Shoot with Auto Focus and Manual Focus at the Same Time
Using Back Button Focusing can help you really dial in the focus in your pictures. Since the shutter button is assigned to only activate the shutter, you can use Back Button Focusing to start the focus, and then really dial it in by manually adjusting the focus ring on the lens. This is especially usefully for shooting landscapes.
I shoot all my landscape photos using a remote trigger and the mirror-up function, but that is an article for another day. Until recently, I used the remote to activate the focus system and also the shutter. Since discovering using Back Button Focusing for landscapes, now my remote trigger ONLY activates the shutter. First, I set my aperture, shutter, and ISO. Then I use the LCD screen and Back Button Focusing to dial in my focus. Once I have my setting and focus ready, I simply use the remote to activate the shutter and take the picture. The picture below is a great example of using Back Button Focusing to achieve the shot. Had my remote trigger activated the auto-focus and then the shutter, I could have possibly missed the flow of the water.
How to Set Up Back Button Focusing
Nikon:
- Under the Menu go to “Custom Settings”
- Select “Auto Focus”
- Select “AF Activation”
- Select “AF-On Only”
I shoot with a D850 which has a dedicated “AF-On” button on the back. When I shot with my D7100 I would have to assign the “AE-L/AF-L” button on the back to act as the button.
Canon:
- Under the Menu go to “Custom Functions”
- Open “Custom Controls”
- Set shutter button to “Metering Start”
- Set the “AF-On” to “Metering & AF Start”
Sony:
- Open Menu
- Select “AF with Shutter” and turn to Off
Night Photography
Look To The Skies
