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Back button focus on Canon R8 - Any significant advantages?

mmbrombe
Contributor

I am extremely pleased with the performance of my new Canon R8. I have started shooting wildlife and birds in flight with the RF 100-400mm, and am very happy with the results (I am not a pro, but a happy amateur). I have also been watching quite a few videos and reading articles describing the (alleged) advantages of back button focus for this kind of photography. I find the autofocus of my camera+lens incredibly fast and accurate, so I'm wondering if an amateur photographer like me would notice a significant improvement by switching to BBF. I already have quite a few buttons customized to my style, so I'd be losing some functionality. Any thoughts are appreciated, thanks!

6 REPLIES 6

Waddizzle
Legend
Legend

Back Button Focus, BBF, does not improve AF performance or cause you to capture sharper images.  It is most often used to allow the photographer to acquire a subject more precisely for the AF system to track when using AI Servo or AF Servo modes..  

The most commonly used button for BBF has been the [AF-ON] button.  The only setup involved is removing AF from the Shutter Button.  The factory default behavior for [AF-ON] already turns on the AF system in the camera.  The Shutter will only enable Metering.

When I use BBF to track fast moving subjects such as sports or wildlife, I set up the [AF-ON] as [AF-OFF].  I have found it is easier to hand hold the camera without pressing two buttons with my right hand at the same time.  It reduces fatigue in my hands.  

Why do it that way?  I occasionally find need to “pause” the AF system should I lose tracking on my moving subject.  A quick tap of the [AF-OFF] button resets the AF point back to the center and I can quickly and easily reacquire my subject again.

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"The right mouse button is your friend."

Thank you for your reply, however I am confused about your setup. If AF is disconnected from the shutter button and [AF-ON] is set to [AF-OFF], how do you start auto-focusing? Pardon my ignorance, still getting acquainted with the Canon system. 

Bill will respond for his setup.  When I want the camera to focus, I prod the AF button and it focuses and locks.  If the subject is moving, with servo AF set, I just hold the AF button and it will track continuously.

The following video from Canon Oz may be helpful:


cheers, TREVOR

Before you ask us, have you looked in the manual or on the Canon Support Site?
"All the variety, all the charm, all the beauty of life is made up of light and shadow", Leo Tolstoy;
"Skill in photography is acquired by practice and not by purchase" Percy W. Harris


@mmbrombe wrote:

Thank you for your reply, however I am confused about your setup. If AF is disconnected from the shutter button and [AF-ON] is set to [AF-OFF], how do you start auto-focusing? Pardon my ignorance, still getting acquainted with the Canon system. 


I just simply press the Shutter.  I do not reprogram it.  I allow it to retain its factory default behavior.  In fact, because I only have to press one button, I can acquire the subject and capture the shot much faster than if I had to press two buttons.

--------------------------------------------------------
"The right mouse button is your friend."

Tronhard
Elite
Elite

BBF is benefit based on several factors, such as subject, environment and how one likes to use a camera, or how much control one wants to give to the tech as much as anything. Like Bill (Waddizzle), I shoot exclusively with BBF, and in fact I set the * button to its right to allow me to lock AF as well, and I have done so for many years.

Most cameras these days are reasonably good at guessing focus and exposure, but they are by no means foolproof and will sometimes select values or locations that work for the algorithm but not for the shooter.   FWIW, here is how I set my camera up and why.

I have focus disabled from the shutter button, and BBF is already set by default for most Canon Cameras.  Since I shoot with several different makes and models of camera, the details vary a  bit and that is also why I chose a focusing and exposure system that works across them all.

Essentially, I shoot in single point focus with servo and eye tracking.   If the subject is static, I place my focus point on the eye of the subject, prod the BBF button and it locks focus.  If the subject is moving, and if the camera model does not have eye tracking, I hold down the BBF button to track.  Some models do not require that process.  The reason I have set up single point specifically is to be able to isolate the eye of the subject.   That is particularly relevant in deep forest of bush when I am working with birds that are small, flit a lot, and don't come out into the open much.  Just having eye tracking alone would decrease my control as a focusing system often gets distracted by leaves and branches.  One of the features I use is the assignment of the centre button of the rear control wheel to centre the focus point.  So, if for some reason I lose track or the camera finds it hard to get a lock in dim conditions, I can just centre the eye on the screen, lock the focus point and then it will usually track.  My R5 and R6 units have the benefit of different eye/head tracking modes, and I have assigned each with a specific set of other parameters to each of the C1-3 mode values for fast configuration.  This is less of an issue with the R6II, as its new Auto feature is reasonable good at figuring out what to track and holding that.

I choose to use single-point exposure, assigned to the * button, to allow me to determine what I consider has the closest to mid-tone value in an image.  Again, using a single point gives me precision.   In operation, when one gets used to it, the process of acquiring and locking both takes very little time, as the two buttons are adjacent, and I get a fairly high keeper rate.

In the example below, of an Elegant Green Gecko (AKA Auckland Green Gecko), an animal that is barely 125mm (5") from nose to tail, it was taken in extremely dim light, and the DoF is wafer thin, with lots of distracting elements as the animal's camouflage merges so well with its surroundings.

Canon EOS R5, RF100-500@300mm, f/13, 1/500sec, ISO-3200Canon EOS R5, RF100-500@300mm, f/13, 1/500sec, ISO-3200

In this case the gannet was tracking along at a fair pace with the seaweed flapping in its eye (causing a fairly spectacular crash landing later).

Canon EOS 7DMkII, EF 70-300MkII@ 189mm, f/8, 1/1000sec, ISO-200Canon EOS 7DMkII, EF 70-300MkII@ 189mm, f/8, 1/1000sec, ISO-200

 

Canon EOS R5, RF 24-240@ 240mm f/8, 1/500sec, ISO-200Canon EOS R5, RF 24-240@ 240mm f/8, 1/500sec, ISO-200


cheers, TREVOR

Before you ask us, have you looked in the manual or on the Canon Support Site?
"All the variety, all the charm, all the beauty of life is made up of light and shadow", Leo Tolstoy;
"Skill in photography is acquired by practice and not by purchase" Percy W. Harris

Thank you much for the detailed reply and stunning pictures, very inspirational. I have indeed digested the entire R8 manual (quite a few times) since I  take great pleasure in reading and better understanding the capabilities of any camera I have. My concern was not in the implementation of BBF on the R8 (which the manual and YouTube videos cover extensively), but the advantages for those who use it. My conclusion is that it is certainly worth a try since, as you mentioned, the setup is quite simple on the R8. Thank you again.

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