5D Mark IV touch focus doesn't work for stills in live mode if you set back button focus

[cpanddp]

Very annoyed that touch screen focus in live view does not work if you set back button focus. It does however work in video mode. Have to go back into custom controls and remove the back button focus to enabe touchscreen focus which is ridiculous.

Cannon please fix this engineering oversight in a new firmware release. Many of us use back button focus.

[RobertTheFat]

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@cpanddp wrote:

Very annoyed that touch screen focus in live view does not work if you set back button focus. It does however work in video mode. Have to go back into custom controls and remove the back button focus to enabe touchscreen focus which is ridiculous.

Cannon please fix this engineering oversight in a new firmware release. Many of us use back button focus.

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Presumably it's a way to keep you from providing conflicting signals to the camera. If touch screen focus is seen as an extension of shutter button focus, it could conceivably be subject to the same option that lets you disable shutter button focus when back button focus is in effect. I assume you've ruled out that possibility?

[cpanddp]

Thanks for response Robert

But why then in video mode am I able to focus both using both back button focus or touch screen. Seems inconsistent.

My preference in live view would be to be able to use either touch screen or back button focus without having to go into custom controls everytime to disable back button focus to use touch scrren as it works for video.

[Waddizzle]

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@cpanddp wrote:

Thanks for response Robert

But why then in video mode am I able to focus both using both back button focus or touch screen. Seems inconsistent.

My preference in live view would be to be able to use either touch screen or back button focus without having to go into custom controls everytime to disable back button focus to use touch scrren as it works for video.

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What role does the shutter button serve in video mode?  None that I know about.

[cpanddp]

Waddizzle not sure I understand your reposnse. I am talking about focus. In video mode if I have back button focus set I can either choose to focus via back button focus or touch screen without having to disable back button focus in custom controls as I do for stills.

[Waddizzle]

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@cpanddp wrote:

Waddizzle not sure I understand your reposnse. I am talking about focus. In video mode if I have back button focus set I can either choose to focus via back button focus or touch screen without having to disable back button focus in custom controls as I do for stills.

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My question is pretty simple.  What role does the shutter button have when you're shooting video? 

I think Robert's explantion is likely correct.  My 6D exhibits the same behavior, BTW.

[Tim]

Hello cpanddp, 

With regards to the back button auto focusing on your EOS 5D Mark IV, we  have additional questions that we'd like to ask so that ourselves or the community may better assist you. 

-  Which button do you have set in Custom Controls for the back button auto focus?  

-  Whichever button you have set, does the AF ON button work in conjunction with touch AF?  

-  Are you attempting to touch AF whilst the camera has already locked onto focus?

Your responses will help clarify this issue for the community.  

[cpanddp]

I poosted a response

[cpanddp]

With regards to the back button auto focusing on your EOS 5D Mark IV, we  have additional questions that we'd like to ask so that ourselves or the community may better assist you. 

-  Which button do you have set in Custom Controls for the back button auto focus?

AE Lock *  set in custom controls to AF (back button focus)

All others set to  default

-  Whichever button you have set, does the AF ON button work in conjunction with touch AF?  

AF ON button by defaut is set to AF and works but touch screen focus does not in Live View mode

-  Are you attempting to touch AF whilst the camera has already locked onto focus?

No. I even put lens out of focus and will not focus in Live View through touch screen

All you need do is set the AE lock * to AF and touch screen focus no longer works in Live View mode. Even CPS in NJ duplucated and said they would report it. It is quite easy to replicate.

Your responses will help clarify this issue for the community.  

[RobertTheFat]

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@cpanddp wrote:

Thanks for response Robert

But why then in video mode am I able to focus both using both back button focus or touch screen. Seems inconsistent.

My preference in live view would be to be able to use either touch screen or back button focus without having to go into custom controls everytime to disable back button focus to use touch scrren as it works for video.

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I'll answer your question with a guess, because I don't really know. But I do think my guess has a ring of truthiness about it:

Once you start a video, the shutter button isn't used anymore. So there's no reason to disassign AF from the shutter button by default when back-button focus is in use. So if the camera sees touch-screen focus as just another face of shutter-button focus, it (touch-screen focus) will continue to work.

But when you're shooting stills with back-button focus, you normally don't want shutter-button focus active, so the camera turns it off by default, which has the effect of disabling touch-screen focus as well. I've always been under the impression that there's an option to leave both shutter-button focus and back-button focus active at the same time, but I wasn't able to find it in the 5D4 manual, whose description of BB focus is virtually nonexistent. My suspicion is that the drawbacks to having both modes active at once would outweigh the advantage of having touch-screen focus available, but YMMV.