D700 manual lens focus question

[GHP]

Hello all.
I once read somewhere (don't recall where) that it is possible, when using a manual focus lens that you can set the camera to only fire the shutter when the green focus confirmation dot is lit.
In other words, hold down the shutter release, turn focus ring, and shutter releases only when focus is achieved on the active focus point.
I have tried, but cannot get it to do this. Am I missing something, or was I dreaming?
Can any-one advise on this possibility?
Cheers,
Gary

 

[Vivid Art]

I think you have slightly misread what the function does. You can set the camera so that it will only release the shutter when the focus confirmation is on and you subsequently press the shutter release. If the focus confirmation is not on then the camera won't fire. Unfortunately this doesn't allow you to hold down the shutter release and turn the focus ring until it fires.

 

[gad-westy]

I think it's referred to as 'trap focus'. You need option A1 or A2 depending on whether your selector is on Af-S or AF-C focus (it doesn't matter which with manual lenses of course). Set either of theses options to 'focus' and then you can do exactly as you say and hold the shutter down and adjust focus until the camera fires. It's a technique more commonly used with a shutter lock cable where the camera is left and will fire every time something comes into shot in focus, wildlife for example.

 

[GHP]

I think it's referred to as 'trap focus'. You need option A1 or A2 depending on whether your selector is on Af-S or AF-C focus (it doesn't matter which with manual lenses of course). Set either of theses options to 'focus' and then you can do exactly as you say and hold the shutter down and adjust focus until the camera fires. It's a technique more commonly used with a shutter lock cable where the camera is left and will fire every time something comes into shot in focus, wildlife for example.

This is exactly what I was trying to do, but with no success, unfortunately.
I thought it would be a good way of nailing focus with my Samyang 85mm f1.4, but I can't get it to work.

I think you have slightly misread what the function does. You can set the camera so that it will only release the shutter when the focus confirmation is on and you subsequently press the shutter release. If the focus confirmation is not on then the camera won't fire. Unfortunately this doesn't allow you to hold down the shutter release and turn the focus ring until it fires.

I think you may be right.


Anyone else have any thoughts?

 

[gad-westy]

I tried it on mine before typing that reply. Seems to work just fine if you manual focus with an AF lens but just tried the samyang and that doesn't work so presumably it only works with AF lenses unless anybody knows a work around.

 

[GHP]

I tried it on mine before typing that reply. Seems to work just fine if you manual focus with an AF lens but just tried the samyang and that doesn't work so presumably it only works with AF lenses unless anybody knows a work around.

Ha, you must have read my mind !!
I was just wondering whether it needed to be an AF lens in manual mode for it to work.
So, I just tried it with my 50mm AF s. It seems it will release the shutter even if it is not focussed, despite having set it to focus in a1, a2.
Now I really am confused.
Normally I use back button focus, in AF-C, release mode.

 

[gad-westy]

You've got me curious now so just had a play again myself with a 50mm 1.4 AF-S lens.

I always use back button focussing myself so AF selector never moves from AF-C. In AF-C priority selection, menu a1 on the auto focus menu, I usually have it on 'release' but in order to use trap focus, I switched it to the third option, 'focus'.

When I then point the camera at something and push and hold the shutter button, it won't take a photo until I manually focus the lens correctly. This doesn't seem to be what is happening on your's though?

One thing I did notice it that if I switch the selector on the lens itself to manual focus, the camera will take a picture regardless of focus. On a practical level, this means that 'trap focus' is only going to work on a lens that allows full time manual focus override.

One last thing, in case it matters, my firmware is 1.02.

Had a quick look on google to see if there is a proper work around for manual focus lenses but it seems many people have asked but nobody has an answer. Seems a bit odd of nikon for their cameras to work in this way.

 

[GHP]

You've got me curious now so just had a play again myself with a 50mm 1.4 AF-S lens.

I always use back button focussing myself so AF selector never moves from AF-C. In AF-C priority selection, menu a1 on the auto focus menu, I usually have it on 'release' but in order to use trap focus, I switched it to the third option, 'focus'.

When I then point the camera at something and push and hold the shutter button, it won't take a photo until I manually focus the lens correctly. This doesn't seem to be what is happening on your's though?

One thing I did notice it that if I switch the selector on the lens itself to manual focus, the camera will take a picture regardless of focus. On a practical level, this means that 'trap focus' is only going to work on a lens that allows full time manual focus override.

One last thing, in case it matters, my firmware is 1.02.

Had a quick look on google to see if there is a proper work around for manual focus lenses but it seems many people have asked but nobody has an answer. Seems a bit odd of nikon for their cameras to work in this way.

Thanks for your help, Graham.
I have replicated your settings, and now it's doing exactly what you describe.(I did have the lens on "manual")
It seems I can't use it in the way I wanted, as I was trying it not only with my Samyang 85mm, but I also have some older Nikon AIS lenses too, which was what prompted me to try.
Oh well, the best laid plans and all that.

I might look into getting a Katzeye screen though.

Cheers,
Gary.

 

[gad-westy]

Have read plenty of other moans about this anomaly on the net. Cannot for the life of me work out what the reason to disable this for manual lenses is as you'd think it would be at it's most useful for manual lenses. It could be worse though, I read that the function has gone all together on the D800. I'm sure there is a logic to it all somewhere but I can't work it out.

 

[Martyn...]

Have read plenty of other moans about this anomaly on the net. Cannot for the life of me work out what the reason to disable this for manual lenses is as you'd think it would be at it's most useful for manual lenses. It could be worse though, I read that the function has gone all together on the D800. I'm sure there is a logic to it all somewhere but I can't work it out.

It is more likely the electronics in the newer lenses allow it to function that way, whereas the older and third party stuff do not have the function on the chip.

 

[gad-westy]

It is more likely the electronics in the newer lenses allow it to function that way, whereas the older and third party stuff do not have the function on the chip.

It's strange though because the camera is capable of giving a focus confirmation dot/beep for any of those lenses so you would think it has all the information it needs to link that to the shutter release.

 

[Martyn...]

It's strange though because the camera is capable of giving a focus confirmation dot/beep for any of those lenses so you would think it has all the information it needs to link that to the shutter release.

I know but for some strange reason it will not do it.

I read a thread about this some time ago over on FM, I do not think anyone on there came up with a conclusion as to why it will not do it.

Personally I have no problem focusing my Zeiss or AiS lenses on the D700 using the standard screen, relying on my eyes and paying attention to the green dot.