Back button focus
Dec 30, 2014 10:53:53 #
My Nikon camera is set up as follows:
AF-ON only
Single Servo Mode
Normally I focus with the Back button (AF-On), when it beeps I release the AF-On button, recompose and squeeze the shutter release button which deals with exposure and trips the shutter. Never have a problem with this - until today.
I have dust on my sensor so needed to shoot a white background.
Using the AF-On, I focussed on the edge of the background, released the AF-On button, recomposed to get the whole of the white area in the viewfinder, pressed the shutter button and . . . nothing.
I tried again, this time with no recompose and the camera worked fine.
The only way I could get the image I was seeking was to switch the lens to manual focus.
So my question is: If I set the AF-On button to AF-On only, is the shutter release button still trying to focus and refusing to allow the photo because it can't focus on a blank white sheet?
Or am I doing or not doing something else incorrectly?
AF-ON only
Single Servo Mode
Normally I focus with the Back button (AF-On), when it beeps I release the AF-On button, recompose and squeeze the shutter release button which deals with exposure and trips the shutter. Never have a problem with this - until today.
I have dust on my sensor so needed to shoot a white background.
Using the AF-On, I focussed on the edge of the background, released the AF-On button, recomposed to get the whole of the white area in the viewfinder, pressed the shutter button and . . . nothing.
I tried again, this time with no recompose and the camera worked fine.
The only way I could get the image I was seeking was to switch the lens to manual focus.
So my question is: If I set the AF-On button to AF-On only, is the shutter release button still trying to focus and refusing to allow the photo because it can't focus on a blank white sheet?
Or am I doing or not doing something else incorrectly?
Dec 30, 2014 10:58:30 #
Dec 30, 2014 11:00:23 #
Dec 30, 2014 11:04:00 #
BigBear wrote:
Do you have AF on set on both buttons ??
Not sure what you mean.
In the camera menu, Autofocus > AF Activation there are two choices,
Shutter/AF-ON
AF-ON only
So I have the latter selected.
Dec 30, 2014 11:12:32 #
On my Canon custom Control menu I show the Lens AF Stop Button to AF-OFF and everything works. like you said for BBF button. Check that.
Searcher wrote:
My Nikon camera is set up as follows: br br AF-ON... (show quote)
Dec 30, 2014 11:21:29 #
Make sure A1 is set to Release and A4 is set to AF-ON only for BFF. On my D800 with these settings I loose the focus beep and will only work with AF-C.
Dec 30, 2014 11:25:00 #
Searcher wrote:
Not sure what you mean.
In the camera menu, Autofocus > AF Activation there are two choices,
Shutter/AF-ON
AF-ON only
So I have the latter selected.
In the camera menu, Autofocus > AF Activation there are two choices,
Shutter/AF-ON
AF-ON only
So I have the latter selected.
I'm not that familiar with Nikon, but it looks like you can only choose one button or the other. So at this point I don't have an idea what it is doing.
Dec 30, 2014 11:28:59 #
Did you hear beep when you tried to focus on white subject /camera has problem when subject does not have contrast/? What exposure mode did you use? What AF-S priority Selection /Release or Focus/? I am using for this task manual exposure mode and smallest aperture without focusing.
Searcher wrote:
My Nikon camera is set up as follows: br br AF-ON... (show quote)
Dec 30, 2014 11:30:05 #
nikonwaddy wrote:
Make sure A1 is set to Release and A4 is set to AF-ON only for BFF. On my D800 with these settings I loose the focus beep and will only work with AF-C.
That did the trick, thank you.
Still puzzled though, the lens was focussed (Sensor plane to edge of background and sensor plane to all over white background being the same) so pressing the AF-ON button = focussed, move the camera to the left but maintain exact distance (tripod on a dolly) I would have thought should have allowed the camera to fire without having to invoke focus release.
Dec 30, 2014 11:49:53 #
Searcher wrote:
That did the trick, thank you.
Still puzzled though, the lens was focussed (Sensor plane to edge of background and sensor plane to all over white background being the same) so pressing the AF-ON button = focussed, move the camera to the left but maintain exact distance (tripod on a dolly) I would have thought should have allowed the camera to fire without having to invoke focus release.
Still puzzled though, the lens was focussed (Sensor plane to edge of background and sensor plane to all over white background being the same) so pressing the AF-ON button = focussed, move the camera to the left but maintain exact distance (tripod on a dolly) I would have thought should have allowed the camera to fire without having to invoke focus release.
It was because of the way you had it set to focus. If you have it set to hear the beep when focused, and you move the camera and it can't find edges to focus on, it thinks it's out of focus and therefore won't shoot. By putting your camera settings to AF-C and losing the beep, it will shoot if it's focused or not.
Dec 30, 2014 12:54:51 #
Searcher wrote:
That did the trick, thank you.
Still puzzled though, the lens was focussed (Sensor plane to edge of background and sensor plane to all over white background being the same) so pressing the AF-ON button = focussed, move the camera to the left but maintain exact distance (tripod on a dolly) I would have thought should have allowed the camera to fire without having to invoke focus release.
Still puzzled though, the lens was focussed (Sensor plane to edge of background and sensor plane to all over white background being the same) so pressing the AF-ON button = focussed, move the camera to the left but maintain exact distance (tripod on a dolly) I would have thought should have allowed the camera to fire without having to invoke focus release.
the camera does no look to see if it was focused, it looks to see if it is focused.
With no contrast/phase info coming in it can't tell and fais to fire.
Removing "in focus" requirement from your shutter button solved your problem.
Dec 30, 2014 13:09:24 #
oldtigger wrote:
the camera does no look to see if it was focused, it looks to see if it is focused.
With no contrast/phase info coming in it can't tell and fais to fire.
Removing "in focus" requirement from your shutter button solved your problem.
With no contrast/phase info coming in it can't tell and fais to fire.
Removing "in focus" requirement from your shutter button solved your problem.
Now I understand, thanks to all.
Dec 31, 2014 10:47:42 #
Searcher wrote:
My Nikon camera is set up as follows: br br AF-ON... (show quote)
Here is one idea:
Check Custom Setting a2
if: (per d-810 manual on page 307)
Release: Photos can be taken whenever the shutter release button is pressed.
Focus: Photos can be taken only when the in focus indicator is displayed.
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