# back button AF on EOS R



## jeanluc (Nov 1, 2018)

There is a post in the "rumors" section that when you use back button AF on the R to focus and recompose, the camera will try to refocus after you recompose! Can any R owners comment on this?

I would think that as long as you are in one shot AF mode as opposed to servo, once you lock focus that focus point would hold unless you refocus. I cannot imagine it would refocus on whatever it chooses if you recompose.

I have an M5, and it works just like a DSLR, ie. you can focus and recompose without your selected focus point being over ridden.

Also, is the IS always on when the camera is on, or does it only work when you half push the shutter like on a DSLR? I would hope its not always on....I suspect that would obviously be bad for battery life and also be hard on the AI system in the lens with time.

Thanks for any info, as I am likely going to go ahead and get an R and just want to make sure this is not an issue, since I focus and recompose all the time!


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## bhf3737 (Nov 1, 2018)

I figured out that after setting AF-on button to back-button-focus you have to disable "continuous auto focus" in the menus, too. It does not get disabled by default. Otherwise it works fine.


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## jeanluc (Nov 1, 2018)

bhf3737 said:


> I figured out that after setting AF-on button to back-button-focus you have to disable "continuous auto focus" in the menus, too. It does not get disabled by default. Otherwise it works fine.


Thanks! Normally for landscapes on my 5d4, using live view, I’ll use back button AF to focus on say a foreground element, then move the AF point to whatever I want to meter on, say the sky. Then I will take the shot. It stays focus locked on the foreground element as you would expect. So the R works the same way as long as continuous AF is disabled?


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## Mt Spokane Photography (Nov 1, 2018)

jeanluc said:


> Thanks! Normally for landscapes on my 5d4, using live view, I’ll use back button AF to focus on say a foreground element, then move the AF point to whatever I want to meter on, say the sky. Then I will take the shot. It stays focus locked on the foreground element as you would expect. So the R works the same way as long as continuous AF is disabled?


The 5D MK IV does not meter on a spot AF point. The R works the same way.


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## jeanluc (Nov 2, 2018)

True. But in live view, if you focus on something and then move the AF box around on the touchscreen around, the exposure does change. For example if you move it from a bright area to a dark one the exposure is different. I’ll often focus on a foreground element, then move the af box to the bright sky and shoot that shot for the highlights. Then I’ll move it to a shadowed area and shoot that as well. The two exposures will be different for sure. That gives me what I need to exposure blend if the DR is very high. All the while the af stays locked on whatever I first chose to focus on. Which is who if the R keeps changing af every time you move the af square, it would be a problem. But if you can turn Continuous AF off, no proble


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## dak723 (Nov 2, 2018)

jeanluc said:


> True. But in live view, if you focus on something and then move the AF box around on the touchscreen around, the exposure does change. For example if you move it from a bright area to a dark one the exposure is different. I’ll often focus on a foreground element, then move the af box to the bright sky and shoot that shot for the highlights. Then I’ll move it to a shadowed area and shoot that as well. The two exposures will be different for sure. That gives me what I need to exposure blend if the DR is very high. All the while the af stays locked on whatever I first chose to focus on. Which is who if the R keeps changing af every time you move the af square, it would be a problem. But if you can turn Continuous AF off, no proble



You can customize when and if your exposure is locked or not during button half-press. Page 548 of the PDF manual.


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## Mt Spokane Photography (Nov 2, 2018)

jeanluc said:


> True. But in live view, if you focus on something and then move the AF box around on the touchscreen around, the exposure does change. For example if you move it from a bright area to a dark one the exposure is different. I’ll often focus on a foreground element, then move the af box to the bright sky and shoot that shot for the highlights. Then I’ll move it to a shadowed area and shoot that as well. The two exposures will be different for sure. That gives me what I need to exposure blend if the DR is very high. All the while the af stays locked on whatever I first chose to focus on. Which is who if the R keeps changing af every time you move the af square, it would be a problem. But if you can turn Continuous AF off, no proble



The R pretty much acts like live view on my 5D MK IV, not a lot of difference really. And yes, in live view, the exposure is averaged around the AF point, I thought you were talking the standard operation. I prefer to use liveview on my MK IV as well, so my R is a bit better, due to having the EVF.


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## jeanluc (Nov 2, 2018)

Mt Spokane Photography said:


> The R pretty much acts like live view on my 5D MK IV, not a lot of difference really. And yes, in live view, the exposure is averaged around the AF point, I thought you were talking the standard operation. I prefer to use liveview on my MK IV as well, so my R is a bit better, due to having the EVF.


Good to know, thanks! The AF thing had me worried, but if it is just like my 5d4 it sounds great!


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## jeanluc (Nov 4, 2018)

Update....I tried out an R today using “live view” ie the back screen to shoot as described above and unlike the 5D4 or even the M5 you do not have to press the AF button to focus. As soon as you place the AF square on the touchscreen, it focuses. You do not need to press the AF button If you try to then move it to another place to change exposure, it will refocus immediately. You cannot lock focus. This happens even with Continuous AF disabled. 

The work around seems to be to program the four way pad control on the back to move the AF point.....then you can move the AF point to another location without it automatically refocussing. 

There does not appear to be a way to turn off this “automatic focus” thing so that it only focusses when you want ie. when you press the AF button. Is there a way I couldn’t find?

I hope this is addressed in the future, as it seems strange indeed that you can’t turn this off.


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## Viggo (Nov 5, 2018)

I JUST thinking about that yesterday. It is annoying...


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## Valvebounce (Nov 5, 2018)

Hi Jeanluc. 
Is that a result of having touch to focus turned on or is that there is not a way to turn off touch to focus short of flicking the manual focus switch on the lens? 

Cheers, Graham. 



jeanluc said:


> Update....I tried out an R today using “live view” ie the back screen to shoot as described above and unlike the 5D4 or even the M5 you do not have to press the AF button to focus. As soon as you place the AF square on the touchscreen, it focuses. You do not need to press the AF button If you try to then move it to another place to change exposure, it will refocus immediately. You cannot lock focus. This happens even with Continuous AF disabled.
> 
> The work around seems to be to program the four way pad control on the back to move the AF point.....then you can move the AF point to another location without it automatically refocussing.
> 
> ...


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## jeanluc (Nov 5, 2018)

I am not sure if you can turn the “touch focus” off. You can for sure turn off the “touch shutter”, but that does not seem to turn the touch focus off. 

I am just trying to figure out how to make the R act like my 5d4 in live view. 

When I shoot a high DR landscape with a dark foreground and bright sky like a sunset, I use live view, place the AF square on my subject, typically a foreground object. Then I focus on this with back button AF( my shutter button only takes the shot, I have AF for shutter half press turned off on custom controls).I then take the shot, which is exposed for the foreground. 

Then I selectthe brightest area , like the sky in a sunset. I then move the AF point there with the Touchscreen. This changes the exposure to reflect the “new” location of the AF square. I do not press the AF button, so the focus does not change, ie my foreground is still in focus. I then take the shot which will be exposed for the sky. That way I can exposure blend if I need to in post. 

I’m just trying to get the R to do this, like any Canon dslr or even the M5 does. 

If you turn the lens to MF on an R, the AF square goes away and you can’t control where the camera centers it’s metering on. And if you move the AF with the touchscreen as above, it refocuses, Even if you don’t want to!

If there is a way to turn off the touch focus, is sure like to know. The point of using back button AF is so the user can tell the camera when to focus. There has to be a way, other than the work around I described above. 

If any R users, have an answer, that’s be great to hear. Hopefully what I’m trying to ask makes sense....


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## Larsskv (Nov 5, 2018)

jeanluc said:


> I am not sure if you can turn the “touch focus” off. You can for sure turn off the “touch shutter”, but that does not seem to turn the touch focus off.
> 
> I am just trying to figure out how to make the R act like my 5d4 in live view.
> 
> ...



Hmmm... the issue you (and others) are debating here... why not get the exposure first, lock it using the lock button, and then focus on your subject? That should solve the problem in an easy way, shouldn’t it?


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## jeanluc (Nov 6, 2018)

Larsskv said:


> Hmmm... the issue you (and others) are debating here... why not get the exposure first, lock it using the lock button, and then focus on your subject? That should solve the problem in an easy way, shouldn’t it?



Hmmm....would this work? (For hypothetical sunset inage with bright sky and dark foreground, using back lcd screen). 

Compose on rear lcd. 

Place green AF square over bright sun. Camera focuses.

Press * button to get exposure “correct” for bright highlights. 

Move green AF square over whatever you want in focus, say dark foreground. 
Camera refocuses.

Take shot.

If this works, boy do I feel dumb....


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## Mt Spokane Photography (Nov 6, 2018)

jeanluc said:


> Hmmm....would this work? (For hypothetical sunset inage with bright sky and dark foreground, using back lcd screen).
> 
> Compose on rear lcd.
> 
> ...




Yes, that works to lock the exposure so that then touching a different place focuses but the exposure does not change, even if lighting is very different.


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## Larsskv (Nov 6, 2018)

jeanluc said:


> Hmmm....would this work? (For hypothetical sunset inage with bright sky and dark foreground, using back lcd screen).
> 
> Compose on rear lcd.
> 
> ...



No need to feel dumb. The lock button has never been a part of my workflow, but I reflected on it the other day when I wanted to set another function to the lock button on my EOS R, but couldn't find a way to do it. I thought to myself that Canon must find the lock button quite handy, and that I might be missing out on something since I never use it...


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## jeanluc (Nov 6, 2018)

Thanks for the info everyone. I also have never really used the * (AE lock) button much either. I guess we all develop our personal camera work flow and just stick with what works for us. 

Last question and we can end this thread... when you push the * button, does it meter and lock the exposure, or do you have to half push the shutter to meter, then lock exposure with the * button? The manuals don’t seem to really say 

Again, thanks !


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## Mt Spokane Photography (Nov 6, 2018)

jeanluc said:


> Thanks for the info everyone. I also have never really used the * (AE lock) button much either. I guess we all develop our personal camera work flow and just stick with what works for us.
> 
> Last question and we can end this thread... when you push the * button, does it meter and lock the exposure, or do you have to half push the shutter to meter, then lock exposure with the * button? The manuals don’t seem to really say
> 
> Again, thanks !


You need to focus on the spot you want to meter, touch the screen, bbf, or half press. then lock the exposure. A * will appear on the rear lower right of the viewfinder and lcd even though you focus elsewhere. It stays locked until I press the set button or the play image button, even if I capture the image, so one must remember to disable it to set a new exposure.


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## snappy604 (Nov 6, 2018)

I get it's handy, but if you're doing landscape with live view and tripod.. why wouldn't you just use manual and adjust your aperture/shutter/iso to get the desired exposure and just touch to focus? usually I pre-do my aperture and iso.. and adjust shutter (usually tripod) to get what I need. Incredibly useful to have touch to take pic too.. allows delicate button pressing


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## dwilz (Nov 16, 2018)

mirage said:


> I am aware of the differences. But in being forced to do the asterisk SH*T routing both suck.
> Also, both cameras lack a joystick to select AF field.
> Plus the M.fn-slider on R is a total failure.


regarding the slider. I was watching Duston Abbot's review of the EOS R on youtube. He made a comment that after disabling the slider lock that the slider became a much more usable control. I haven't looked into this yet myself.


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## Viggo (Nov 16, 2018)

dwilz said:


> regarding the slider. I was watching Duston Abbot's review of the EOS R on youtube. He made a comment that after disabling the slider lock that the slider became a much more usable control. I haven't looked into this yet myself.


That is my experience also, I turned off the lock because I now use right tap for histogram and it’s not a crisis to accidentally hit it. And by turning off the lock it’s much more responsive.

I love it now, slide for kelvin adjustment and tap left for level and right tap for histo.


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