LiveView Focus Point

[stephen32]

I just upgraded from the 5dMark II to the Mark IV.  On the old camera I could move the square focus spot around in the frame and that would then also expose for that spot.  On the Mark IV it doesn't appear that I can do that and the manual says that I have to point the spot in the center where I want it to base exposure then recompose.  Is there a setting that I can access to make the focus point also the exposure point?

[Waddizzle]

You should be able to use the joystick to move the AF box around, just as you would for viewfinder shooting.  Except, the joystick might be disabled by default.  You have to go into Custom Controls and turn it on.  Pressing it in ceners the AF point.

Which Live View AF mode are you using?

[stephen32]

I was in spot but will switch to evaluative. The AF box moves around and focus is spot on but was not adjusting exposure while I was in spot. Since I posted I was told that if in evaluative the AF box should also key exposure. Haven't had a chance to try that yet.

[Waddizzle · Accepted solution]

There is no correlation between the selected AF point and how the camera meters.  One has nothing to do with the other in 5D  Series cameras.  All metering is "centered" on the center AF point.  Only the 1D Series of camera bodies are capable of correlating the active AF point to metering.  

This is how you lock exposure and focus at an AF point other than the center AF point.

If you want to focus and recompose with an AF point other than the center, then you need to use AI Servo mode with all AF points active, using the center AF point as the starting point.  Put the center AF point on your subject, and lock exposure.  As you recompose the shot, AF tracking will stay on the subject until you fire the shutter.

[kvbarkley]

"There is no correlation between the selected AF point and how the camera meters"

In my T6S manual it says 

"Evaluative metering (linked to all AF points)"

Though, I don't know exactly what that means.

[Waddizzle]

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@kvbarkley wrote:

"There is no correlation between the selected AF point and how the camera meters"

In my T6S manual it says 

"Evaluative metering (linked to all AF points)"

Though, I don't know exactly what that means.

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I'm not sure what that means, either.  When light from the lens hits the mirror, some goes down to the AF Sensor, and some goes up to the viewfinder.  The prism in the viewfinder directs some of the light towards the top of the viewfinder, which is where the metering sensor is located.

In other words, AF and Metering through the viewfinder are performed by totally separate sensors in most cameras.  

However, the question relates Live View metering, and that is even more vague.  I am not sure if Spot Metering or Center Weighted, or Whatever even apply in Live View.  This is one of those black magic things that I've never given much thought to, because I do not shoot in Live view.  I might focus in Live View, but I will meter and take the shot through the viewfinder.