Most, if not all, professional DSLR and mirrorless cameras will come without being set to back button focus. Instead with their default settings for attaining focus by pressing the shutter button halfway down, and then fully depressed to take a shot.
This method was entirely unknown to me in the early stages of my career. And even when I did discover it, I was still sceptical.
Why on earth would camera makers not make this the default setting if they didn’t believe the default shutter button setting was the optimal method for taking a photo.
And the truth is, this method is the most optimal method for setting focus and taking a shot for nearly all scenarios.
It’s when you need to know you will get every shot 99.9% of the time in all types of scenarios that back button focus becomes essential.
What is Back Button Focus
By default the shutter button will focus on the subject when halfway pressed and then take the shot when you follow through, pressing the shutter button completely.
This method separates these two functions to two separate buttons. Setting focus is removed from the shutter button, leaving it just to just take a shot.
The focus lock is set to another button in close proximity to the thumb.
On Canon setting focus can be reassigned usually to the AE button which is perfect placement for the thumb, with the index finger on the shutter button.
Ostensibly separating these two function seems as though it is taking an easy function and making it more difficult. But in fact it is simplifying what could be a cumbersome process.
Why you should be using Back Button Focus
A good example would be a bride about to walk down the aisle. She’s standing still, so on a Canon, single shot focus is optimal to get the shot.
But then she starts walking and you will need to refocus, so you need to change to AI servo. The time it takes to change mode is time lost that you cannot afford.
This method gives you the best of both worlds without any need to waste time swapping settings.
While the bride is stationary you would press the button you have assigned to focus to lock in focus. And as she’s not moving you have your focus set and are free to take shots.
If she suddenly moves, it’s simply a matter of a millisecond to press the focus button to reattain focus again.
If she is walking continuously, you simply need to keep your hand on the focus button and take your shots.
Unlocking the two functions is such a powerful tool to making sure you are always in the best position to get sharp focus for a subject that alternates between stationary and movement.
Getting quick focus can be the difference in capturing that fleeting moment or missing it completely.
And if your business is built on capturing moments, getting the right focus every time or most is the most important thing to get right first.
Beautiful colours and Bokeh won’t mean a thing if the image is not sharp.
Of course there are many more factors to take into account when getting sharp focus and if you want to read more click here. And used in conjunction with back button focus will help you get there 99% of the time.