Back Button Focus (Page 2): If the back bottom focus does "not work at times" than in all likelihood you are doing something wrong "at times". Review how back button focus works. It is...

Kmgw9v Loc: Miami, Florida

SandraLovesPhotography wrote:

I was hoping you all could help me figure out why the back button focus will not work at times. I am shooting with a Nikon D850 with 85mm lens.In the middle of a shoot, it just won't focus at all. Do you all prefer the back button focus?

If the back bottom focus does "not work at times" than in all likelihood you are doing something wrong "at times".
Review how back button focus works. It is probably not the camera or lens.

billnikon Loc: Pennsylvania/Ohio/Florida/Maui/Oregon/Vermont

SandraLovesPhotography wrote:

I was hoping you all could help me figure out why the back button focus will not work at times. I am shooting with a Nikon D850 with 85mm lens.In the middle of a shoot, it just won't focus at all. Do you all prefer the back button focus?

I do not prefer back button focus. I get better shots with my old fashion front button. I use the button on the back assigned to single spot focus, so when my bird flies into the bush and sits, I can simply push the back button and I go to single spot focus, and then I nail the bird with the button that most camera manufactures have spend thousands of dollars on to make it easy to take a photo with, the one on the top front of the camera.

Steve DeMott Loc: St. Louis, Missouri (Oakville area)

Steve Perry "Secrets to the Nikon Autofocus System" https://backcountrygallery.com/secrets-nikon-autofocus-system/

Excellent read.

jerryc41 Loc: Catskill Mts of NY

SandraLovesPhotography wrote:

I was hoping you all could help me figure out why the back button focus will not work at times. I am shooting with a Nikon D850 with 85mm lens.In the middle of a shoot, it just won't focus at all. Do you all prefer the back button focus?

Sometimes, I wonder if the lens is focusing because I don't notice a change as I look through the viewfinder. When that happens, I focus on something either near or far away - different from where the subject is located. When I do that, I see that the lens is working. Maybe the change in focus is so slight that I didn't notice.

On the other hand, maybe the button on your camera isn't making consistent contact inside the camera. Switch back to shutter button focus for a few days and see if you notice a problem.

jerryc41 Loc: Catskill Mts of NY

Dan R wrote:

I hate to ask this, but could you be too close to your subject for the lens?

Or too far away?

imagemeister Loc: mid east Florida

I really prefer shutter button focus and use the back button for focus lock - this is mainly because shutter button focus works best for me for BIF. The result is the same as BBF only in reverse .

..

charlienow Loc: Hershey, PA

I have the D7200 and occasionally the focus appears to quit working. What I discovered lately was that it was focusing but on a spot close to me on the side and the focus indicator disippeared in the scenery.
Once I discovered this I moved the camera enough that the focus point changed and all was good.

SandraLovesPhotography wrote:

I was hoping you all could help me figure out why the back button focus will not work at times. I am shooting with a Nikon D850 with 85mm lens.In the middle of a shoot, it just won't focus at all. Do you all prefer the back button focus?

pahtspix

I've been using back-button focus for 3+ years, including my Nikon D7000, and my D500.. I have no need to go back to the single button system. BBF has worked flawle
ssly on both cameras!

JeffDavidson Loc: Originally Detroit Now Los Angeles

I use BBF exclusively (that only makes it right for me). Make certain in you Setup menu that the shutter button is disabled for focusing.

2mdman

I too have had that problem on my Nikon 5600 but have not had time to look into it. Usually, as toxdoc42 does, I just depress the shutter button a little bit and that gets it working again. I looked thru Steve Perry's BBAF book but couldn't find any reference to this occurring.

Jaackil Loc: Massachusetts

SandraLovesPhotography wrote:

I was hoping you all could help me figure out why the back button focus will not work at times. I am shooting with a Nikon D850 with 85mm lens.In the middle of a shoot, it just won't focus at all. Do you all prefer the back button focus?

Try cleaning the contacts on the lens and corosponding contacts on the camera. Over time they get dirty and oxidize slightly. This causes a poor contact and will result in intermittent focus issues. You can clean them easily with alcohol and a q-tip or an alcohol wipe.

frankraney Loc: Clovis, Ca.

SandraLovesPhotography wrote:

I was hoping you all could help me figure out why the back button focus will not work at times. I am shooting with a Nikon D850 with 85mm lens.In the middle of a shoot, it just won't focus at all. Do you all prefer the back button focus?

I shoot nikon but not the D850. I use bbf and love it. It allows me to focus then recompose. I did a search on "bbf on d850" and several good videos and articles show and explain this.

Bill_de Loc: US

2mdman wrote:

I too have had that problem on my Nikon 5600 but have not had time to look into it. Usually, as toxdoc42 does, I just depress the shutter button a little bit and that gets it working again. I looked thru Steve Perry's BBAF book but couldn't find any reference to this occurring.

If pressing the shutter button fixes the problem, you did not disengage the shutter button when you decided to start using BBF.

--

Charles P Loc: Southern Central NY State

SandraLovesPhotography wrote:

I was hoping you all could help me figure out why the back button focus will not work at times. I am shooting with a Nikon D850 with 85mm lens.In the middle of a shoot, it just won't focus at all. Do you all prefer the back button focus?

I never use BBF, because I can't do it. I have a problem with my right eye which renders it pretty much useless. I tried BBF, but having to use my left eye for the viewfinder makes it problematic. I have my back button set for exposure lock and hold, and that works great for using a gray card, or setting exposure by using green grass or a gray road or anything that is close to 18% gray. The half press on the shutter button works okay most of the time for focus. When shooting landscapes, I go to live view and manual focus at full zoom on something at the hyperfocal distance. This always works well for me.

SusanFromVermont Loc: Southwest corner of Vermont

2mdman wrote:

I too have had that problem on my Nikon 5600 but have not had time to look into it. Usually, as toxdoc42 does, I just depress the shutter button a little bit and that gets it working again. I looked thru Steve Perry's BBAF book but couldn't find any reference to this occurring.

If you can focus by depressing the shutter button, then you have not got bbf set up properly. It only will work as intended when the shutter button can NOT initiate focus. It should only bring up the information you see in the viewfinder.