Basic locking exposure questions


EOS M6 Mark II
Nov 25, 2014
I have a 5DM3 and am a bit confused by conflicting things I have read about locking exposure.

While using Spot metering, I meter on something and want to lock it so I press the asterisk to lock the exposure

1. Do i need to press and hold the asterisk to maintain the exposure or will pressing it only once maintain the exposure? I tried and it seemed to sometimes hold it for me after pressing it once, though other times I am no so sure.
2. How many shots can I keep the exposure saved for? Can I set exposure once and shoot 50 photos without having to re-meter?



I'm New Here
Apr 28, 2016
1. I'm fairly sure the exposure lock will be retained for a predetermined period of time, the length of which you can configure. You do not need to continually depress the asterisk button.

2. Once you determine your exposure settings, use full manual mode and they won't change until you change them. You can still meter to check your exposure as you go, and even in doing so, the camera will not alter or adjust your exposure.


CR Pro
Apr 3, 2013
Isle of Wight
Hi Kat.
If you press and release the AE lock will hold for the duration of the metering timer, or I believe whilst you keep the shutter button half depressed, it is locked all the time the * shows in the viewfinder.
If you want to take more shots at the same AE lock exposure you must hold down the AE lock button. Page 173.
You can adjust the metering timer from 4s to 30min! Page 356.
Page numbers from the English manual.

Cheers, Graham.