Turning of AF without the Manual switch on Lens

Hello.

I was just wondering if there was anyway to disable the AF on the lens but still leave the AF motors enabled.

The end goal for what I need is that I have a Canon T3i but it will be inside of a camera housing for a long period of time in a difficult area to get to. It will be tethered to a PC using custom tethering software my company uses. But I will be shooting a fixed subject so I don't want it to AF but would still like to have the option to focus from within software (like the Canon EOS Utility Live mode focusing). Is there any thing I can use to help focus this camera while having it not AF on any subject?

I have used a Birgir mount for Cmount camera's before and have also come across this http://theeditman.com …fFocusFromCinem​atics.aspx, but it doesn't allow me to be tethered while using it, which would defeat the purpose. I have done loads of research but sometimes these smaller more unique requests are difficult to find. Any help would be greatly appreciated.

Loving the site by the way, I have recently taken up photography and been shooting some portraits and some sports, its been a blast and this site has been great to get advice and ideas from.

so the object wont be moving and the camera wont be moving? Just pre-focus, turn AF off, and your set

Well that would be fine normally, but I want to be able to remotely adjust focus, if the camera moves in the housing or if the subject moves at all. The camera will be on a pole, on a cruise line, so it may move and I don't want to climb a pole to adjust focus. I need to be able to have focus controls from the bottom of the pole somehow. I want to not let it AF when capturing an image but still have the ability to change the focus from the bottom of the pole, if that makes sense.

ThomasRG wrote in post #14741983
Well that would be fine normally, but I want to be able to remotely adjust focus, if the camera moves in the housing or if the subject moves at all. The camera will be on a pole, on a cruise line, so it may move and I don't want to climb a pole to adjust focus. I need to be able to have focus controls from the bottom of the pole somehow. I want to not let it AF when capturing an image but still have the ability to change the focus from the bottom of the pole, if that makes sense.

in that case, you need two of these:
http://www.bhphotovide​o.com …II_Transceiver_​Radio.html


if you half press the button, the camera will focus. if you press all the way, the camera will take a picture.

Hope this helps?

I don't think that's what they want to do. It sounds like the OP wants to be able to remotely manual focus, not remotely activate the AF.

If the camera moves in the housing, the focus will only change by the small amount that the camera moved. How much do you suppose that the subject might move? Could the depth of focus at a small f-stop cover it?
DOFMaster Depth of Field Calculator with apps for iphone, ipod, palm, android, windoze...

Servo Motor driving a MF rig meant for video might work. That's essentially what Reuters is doing with remote cameras at the Olympics.

Reuters is actually using servos to change focal length on zooms remotely but the same setup would work with remote focus.

Gee, it's a shame you can't just use the EOS Utilities Manual Focus in Live View function...It would be perfect for your application.

Are you sure that you can't somehow incorporate EOS Utilities into your tethering software?

PhotosGuy wrote in post #14742408
If the camera moves in the housing, the focus will only change by the small amount that the camera moved. How much do you suppose that the subject might move? Could the depth of focus at a small f-stop cover it?
DOFMaster Depth of Field Calculator with apps for iphone, ipod, palm, android, windoze...

I don't believe so. I install camera's on roller coasters (Machine Vision) and it will be a similar setup, but not on a roller coaster, and we always get weird/unreliable power, that sometimes shift focus/iris/zoom in an direction.

rrblint wrote in post #14742498
Gee, it's a shame you can't just use the EOS Utilities Manual Focus in Live View function...It would be perfect for your application.

Are you sure that you can't somehow incorporate EOS Utilities into your tethering software?

I wish I could, but it only works via the AF and if that AF is on it will focus on every shot, and I need it to not focus on every shot, but to disable that I have to go to MF on lens and that disables the feature on the EOS software.

FlyingPhotog wrote in post #14742453
Servo Motor driving a MF rig meant for video might work. That's essentially what Reuters is doing with remote cameras at the Olympics.

Reuters is actually using servos to change focal length on zooms remotely but the same setup would work with remote focus.

Any idea on where I could acquire a rig like that?

If you did remote AF, ask yourself...

1. How do you know that the camera has chosen an appropriate AF zone to use, given the fact that there is likely to be all sorts of other objects in the viewfinder...just how does the camera possibly know what YOU have in mind as the primary subject?!
   
2. If you chose a single AF point as the active one, what are the chances that it is on top of the subject location?!
   

Wilt wrote in post #14744770
If you did remote AF, ask yourself...

1. How do you know that the camera has chosen an appropriate AF zone to use, given the fact that there is likely to be all sorts of other objects in the viewfinder...just how does the camera possibly know what YOU have in mind as the primary subject?!
   
2. If you chose a single AF point as the active one, what are the chances that it is on top of the subject location?!
   

I have a tethering software, that I can fire to see a photo and determine what focus is best, also EOS utility has live mode view with a test fire function to see what the focus is focusing on.

ThomasRG wrote in post #14744883
I have a tethering software, that I can fire to see a photo and determine what focus is best, also EOS utility has live mode view with a test fire function to see what the focus is focusing on.

Sure, you can monitor what was focused, but my point was, "How do you CONTROL the AF point selection, rather than be subject to trial and error"?

I just pointed my 40D at a scene with all AF zones active, and (using my back button AF) the camera chose 4 different AF zone combinations during four consecutive presses of the AF button -- and none of them are what I had in mind as the focus point for my 'main subject'!

Using your tethering software on my camera, you would have seen four shots with the wrong AF zone.

ThomasRG wrote in post #14744883
I have a tethering software, that I can fire to see a photo and determine what focus is best, also EOS utility has live mode view with a test fire function to see what the focus is focusing on.

I'm going to ask one more(seemingly) stupid question: Your software fires the camera; AF and AE are both accomplished simultaneously when fired through the software. Would the button assignation on camera make any difference?

IOW, would shunting AF to a back button(which separates AF and AE on camera to two different button pushes) help in any way?

rrblint wrote in post #14744940
I'm going to ask one more(seemingly) stupid question: Your software fires the camera; AF and AE are both accomplished simultaneously when fired through the software. Would the button assignation on camera make any difference?

IOW, would shunting AF to a back button(which separates AF and AE on camera to two different button pushes) help in any way?

Can you explain how I would go about this??