Eric Bornstein Loc: Toronto Canada

I don't know how and do not know why, that is, the advantages and disadvantages, of using back button focus. I am a Nikon user, presently shooting with a D500 (love this camera!). So, there are two questions that I am posing: the how and the why. There may be a third question inherent in my query and that is, the when to use bbf?

jerryc41 Loc: Catskill Mts of NY

This could go on for half a dozen pages.

I tried BBF and quit. Then I went back to it. Using BBF lets you focus on the spot you want and reframe. It also guarantees that the focus won't change when you press the shutter button. I just give me a little more control.

How: it's in the manual, or here: https://www.flickr.com/groups/393420@N25/discuss/72157669060554191/.

Lots of links -
http://nikonrumors.com/2014/01/25/how-to-use-nikons-af-on-and-back-button-autofocus.aspx/
http://digital-photography-school.com/back-button-focus/
https://www.youtube.com/watch?v=8PN9R0D3pF0
http://www.nikonusa.com/en/Learn-And-Explore/Article/hxlkcpoz/benefits-of-using-the-af-on-button-for-autofocus.html
https://www.google.com/search?q=Steve+Perry+Back+Button+Focus&rlz=1C1CHWA_enUS625US625&oq=Steve+Perry+Back+Button+Focus&aqs=chrome..69i57.614j0j4&sourceid=chrome&es_sm=122&ie=UTF-8
https://www.youtube.com/watch?v=d3sLs_8ywY8

Mac Loc: Pittsburgh, Philadelphia now Hernando Co. Fl.

I use BBF on both my Nikon Df and Nikon D7200 and I use it all the time on both. Your manual should give you the steps on how to set it up.

lamiaceae Loc: San Luis Obispo County, CA

Yes, aside from the descriptions of shooting birds in flight. I am curious about this topic too. The one time I tried it, meaning setting my Pentax K-5 to use BBF I seemed to run into some weird issues or errors. I seemed to get strange exposures. Part of that issue might be some odd interaction between my then use of BBF and older "film" lenses. Where I might expect only an indication of focus with a non-AF lens on BBF I seemed to be getting an incorrect exposure (Av AE say) that differed from a Shutter Release exposure. Well, this is getting far beyond the OP question so try answering that and perhaps I'll get some insight into my more specialized issue. My menus will differ greatly from the OP's D500 ones. Any Pentax BBF experts out there too?

Longshadow Loc: Audubon, PA, United States

Once I found out I could set BBF I never went back. I hated exposure lock and focus on the same button. You can't focus on one point and meter on another.

Morning Star Loc: West coast, North of the 49th N.

Eric, All I can tell you why I use BB focus.
I love to take photos of the grandchildren,but like all children they move faster and more unpredictable than quicksilver.
The trampoline and pool they have in the backyard are perfect settings to take photos. Of course, posing is out of the question. Using "regular" focus, that is button halfway down, wait for the beep, shoot! cost me many good pictures because the kids were out of the field before the shutter opened and closed.
Now, I set aperture, focal length and exposure (so that the areas from front to back of trampoline, or front to back of pool are sharp), then press the back button to focus, and wait with the camera at my eye. As soon as I see a "situation" I press the shutter release button all the way down and I got the shot!
You'll need to check your camera's manual to know if you need to hold the BB all the time, or if you can release it once focused.

Steve Perry Loc: Sylvania, Ohio

I did a video on BBAF and it's helped a lot of people understand exactly why they need it and what the advantages are (and how to set it up too). Check it out:

https://www.youtube.com/watch?v=FzqQskGoURE

WayneT Loc: Paris, TN

I wouldn't be without it. It allows me to lock my focus point onto a particular part of the frame I'm trying to create then I let go and I can move my camera to center on a different point without losing my focus on my initial point. Not as many slip ups in focus using BBF vs. front button combination focus and shutter release.

canon Lee

Back button focus gets its name from the fact that the button is on the back of the camera. Focus is disconnected from the shutter button.

crazydaddio Loc: Toronto Ontario Canada

...and AI Servo (for you Canon users).
BBF, AI Servo, Center AF point...all the time.
Crop for artistic effect when you have a winner.
Never miss a shot when there is any risk of movement.

...only time I deviate is for posed portraits with very low DOF (when I use my Sigma @ sub 4.0 aperture). Then I will use manual focus....that lens has well documented AF issues....

I have shot weddings without ever changing those settings.....I will either focus and recompose or manual AF with low DOF where recomposing will make the target in the frame out of focus.

...my preferences...

Whether you choose BBF or not....stick with your choice as it will become fundamental to how you use your camera. When I was making the transition....had to retrain my brain so I was consistent. Missed a lot of shots in the first 21 days.

bdk Loc: Sanibel Fl.

at first I hated it , now I love it, I watched steve Perrys video , it answers all your questions.

kpmac Loc: Ragley, La

Check Steve's video. It will convince you of the benefits. It did for me and once I got used to it I never went back.

Thomas902 Loc: Washington DC

Eric there are several important disadvantages to using back button focus... First let me preface my inferences here with the fact that I use BBF exclusively on location and when shooting events. It's advantages have already been thoroughly address in the thread and they indeed are rather significant to say the least! My shooting style is heavily reliant on BBF especially on location and at events.

However much of my revenue stream comes from studio assignments and here BBF can be a major disadvantage for my visual statement which is heavy based on low key scenarios. My studio is entirely flat black with no windows... All illumination is from modeling lamps which are configured to track with their respected output levels so that I can visually evaluate their influence on compositional elements. These modeling lamps are 150 watts at full power which rarely is reached even with my key light. So yes critical focus in such low ambient can be and is oft a challenge thus I will fall back on Single Servo rather than Continuous Servo on my Nikon bodies in order to obtain a conformation "beep" when the AF system has "lock". Since BBF requires Continuous Servo to function I have to switch it off...

A second very critical issue is I oft will use my D610 rather than my D3x in the studio... The D610 is literally blind as a proverbial bat and struggles to "lock" focus without it's Auto Assist Illuminator. Which obviously is disabled in Continuous Servo. Many of Nikon's pro-sumer bodies rely on their Auto Assist Illuminator without which will struggle in extremely low ambient. BTW: Your D500 does not have an Auto Assist Illuminator most likely because it has excellent low light focusing sensitivity. That said I don't use crop bodies for studio work, nor do my competitors... there are compelling reasons why but that's another issue entirely and unlikely germane to this thread...

Eric I'm certain others here on UHH may not find these limitations relevant but since you asked I wanted you to be aware that as with most aspects of photography so much depends on the needs of your clients especially if you are shooting commercially. Thus the concept of a signal solution is rarely germane in our craft... Hope this makes sense...

Final thoughts? Eric I highly recommend you try BBF in as it's advantages are so significant that your ability to shoot effectively in various challenging situations will likely be compromised without same...

Hope this helps and I wish you well on your journey Eric...

Jim Bob

Check out Steve Perry's video or better still, purchase his new book and I believe your questions will be answered. Oops. See that Steve has jumped in here. Steve, thanks for all you do to help us.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

It's simple. Disengaging the focus acquisition from the shutter gives you flexibility as to when an on what you acquire focus. You can use it in all situations. Keep the button depressed and you can follow an active subject just like if you had the shutter button activate acquisition. If you are in a studio setting shooting a portrait, you can place the focus sensor on an eye, press the back button to acquire focus, then release, and recompose to your preference. When you press the shutter button the camera will not attempt to acquire focus again. BBF is more aptly described as "focus on demand" which means that you never have to switch the camera to AF/S. This also means that if form the habit of using the back button in the manner I described above, you can never miss a shot because you were in the wrong focus mode. You stay in AF/C all the time. Depress and release to make it work like single servo, or keep it pressed to have it work like continuous focus.