Using AF-On vs trigger button for auto focus

Ade

You know the answer actually depends on your own style of shooting so it's hard for anyone else to give a definitive answer.

E.g., suppose you're shooting motorsports -- and you're the type who likes full-time continuous AF tracking on your subjects while taking long bursts on the shutter -- then using AF-ON might be very annoying and unnatural to you because you'll have to continuously press and hold two buttons (AF-ON and the shutter button) instead of just the shutter button.

On the other hand, if you're the type who likes to "pre-focus" at a certain spot or corner (or at the start/finish line), then using AF-ON will feel like a godsend to you because the camera won't change focus on you when you hit the shutter button.

Choosing between AF-ON and shutter half-press is also not an either/or situation. E.g., when shooting fashion in the studio I tend to use AF-ON, but when shooting fashion runway, I'll use the shutter half-press.

PB_PM

E.g., suppose you're shooting motorsports -- and you're the type who likes full-time continuous AF tracking on your subjects while taking long bursts on the shutter -- then using AF-ON might be very annoying and unnatural to you because you'll have to continuously press and hold two buttons (AF-ON and the shutter button) instead of just the shutter button.

AF-ON almost works better in that situation, because the AF-ON activates AF in the breif seconds between shots. On the other hand if you use the shutter button AF is only active when the button is half pressed.

Ade

AF-ON almost works better in that situation, because the AF-ON activates AF in the breif seconds between shots. On the other hand if you use the shutter button AF is only active when the button is half pressed.

Not on any modern Nikon. When in AF-C with either method, while the camera is shooting in burst mode the AF is active, with focus and release governed by the AF-C Priority Selection custom function.

Photobug

AF-ON almost works better in that situation, because the AF-ON activates AF in the breif seconds between shots. On the other hand if you use the shutter button AF is only active when the button is half pressed.

Not on any modern Nikon. When in AF-C with either method, while the camera is shooting in burst mode the AF is active, with focus and release governed by the AF-C Priority Selection custom function.

Good catch.

Parke1953

Ooop's.

Beso

I have used my D800 both ways. In the "normal" or "default" mode either half pressing the shutter button or using the AF-ON provides autofocus. With the camera set to "AF-ON only" the camera will only autofocus using that button. This prevents the accidental shutter release while focusing but it also seems to prevent autofocus when using a remote trigger. I may be doing something wrong or have missed setting something properly but that has been my experience. I am not sure I see the advantage of using "AF-ON only" versus having the option provided in the default setting on a D800. Perhaps someone can enlighten me.

Vipmediastar_JZ

Same thing here @beso. When I use the remote I set it back to normal (i beleive its the same thing when you do the timer). Maybe the new firmware just released will take care of that?

ThomasHorton

The only problem I have had with the AF-on button is that I am left eye dominant. There were times when I was learning to use AF-on that I poked myself in the right eye. LoL

Be a whole lot easier if I were right eye dominant.

PB_PM

This prevents the accidental shutter release while focusing but it also seems to prevent autofocus when using a remote trigger. I may be doing something wrong or have missed setting something properly but that has been my experience. I am not sure I see the advantage of using "AF-ON only" versus having the option provided in the default setting on a D800. Perhaps someone can enlighten me.

It's not just you, AF has always worked that way. I think there should be an option to enable AF via the remote separate from the AF-ON and shutter button.

Beso

Same thing here @beso. When I use the remote I set it back to normal (i beleive its the same thing when you do the timer). Maybe the new firmware just released will take care of that?

@Vipmediastar Sorry to say the firmware update had no effect on the autofocus function with respect to a remote trigger.

Hammie

I was playing with the AF-ON function with my D750. I changed the function of the AE-L/AF-L button to AF-ON and quickly realized that the placement of that button is very uncomfortable, IMO.

In comparison to my D300, which has the dedicated button, I really have to reach with my thumb to use it. It is not in a natural position when holding the camera. My palm actually started cramping a bit due to the stretching of my hand.

Anyone else have any thoughts about this?

spraynpray

You must have small hands. Mine are medium sized and it is ok for me. It would be better if the correct button was there and the rest of the layout was D810 too, but that's marketing for you.

Hammie

I don't think I have small hands. I think it is the way I have been accustomed to holding my camera over the years. The AE/AF button is at about the same position as the D810 and D300, but the AF-ON button is next to it closer to the command dial.

I probably just need to play with it a little more. Rather than resting the camera edge on my joint, I need to position it more on the "meat" of my thumb/palm.

DaveC

I am not sure if my new D750 has a problem or if it is me that has the problem. I had my D300 setup for back button AF. I have tried to do this with the D750.

Setting the AE-L AE-F button to AF-ON, Custom Shooting Menu item f4, seems to then prevent the shutter button from focusing. So far so good. I then set the AF-C and AF-S priorities to Focus only, a1 and a2, expecting that then the camera would not release the shutter if a picture is out of focus. However, no matter if I use AF-S or AF-C the shutter releases when the image is out of focus.

Am I missing something or does the camera have a problem?

Thanks

SOLVED: As is happening quite frequently as I get older, the problem was with me. To test these features I had put the camera into MANUAL focus so of course all the AUTOFOCUS features were inactive. If I keep in AF and point the camera at a monochromatic wall the camera will not focus and the shutter will not release. Duh!!

WestEndFoto

I make those kinds of mistakes every day.

Photobug

Us older shooters fall into that habit. It's fun shaking your head and wondering where you lost those brain cells. LoL ">

Parke1953

Us older shooters fall into that habit. It's fun shaking your head and wondering where you lost those brain cells. LoL ">

In the 60s. LOL.