# Metering with shutter button 1/2?



## SuzukiGS750EZ (Oct 9, 2016)

Hey guys. I saw a video on youtube where the people changed the AF to the AF button on the back of the camera and the shutter button depressed halfway "metered". I do prefer this setup but i'm a bit confused on the "metering" portion. I thought the camera metered in real time? Does this correlate with AE lock or am i way off base here?


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## 480sparky (Oct 9, 2016)

You activate the meter when you half-press the front button.


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## SuzukiGS750EZ (Oct 9, 2016)

The camera seems to always be metering no matter if the button is pushed down or not. Am i missing something?


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## Dave442 (Oct 10, 2016)

If you use Live View then the meter is probably always active. If you use the viewfinder then the meter will stay active for the time you set in the menus.


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## Braineack (Oct 10, 2016)

its always active if the camera is on; at least my D610 is...


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## SuzukiGS750EZ (Oct 10, 2016)

Dave442 said:


> If you use Live View then the meter is probably always active. If you use the viewfinder then the meter will stay active for the time you set in the menus.


That makes perfect sense. So pressing the shutter half way with my metering set to 4 seconds it will Meter and then stop after 4, unless I press the button again. Correct?


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## TCampbell (Oct 11, 2016)

The metering system goes to sleep to save power.  Usually after somewhere around 3-5 seconds.

E.g. if you half-press the shutter then you will "wake up" the metering system and it will go active and stay active (even if you let go) and as you point the camera around you'll see the suggested exposure changing (unless you press the AE Lock button... in which case it will lock in the current metering and it will remain locked until either (a) you take the shot, (b) the metering system goes to sleep (after 3-5 seconds), or (c) you press the AF selection button (which is way to force cancel AE lock without waiting for it to time-out or take a shot.)

Back-button focus is useful when want to control *when* the camera focuses.  It's especially useful for sports shooters who are tracking an athlete, but have to deal with things that get in the way from time to time (another player that you aren't in (e.g. they don't have the ball), a spectator, etc.) this way you can set focus when you *can* see the athlete and it'll remain focused to that distance... if someone gets in the way it will not refocus (unless you press the AF button again.)  If nobody is in the way then you can press-and-hold the AF button (if in AI Servo mode) and the camera will continuously adjust focus as the subject distance changes.


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