Verified Solution: Change the AE Lock button to AE Lock with Hold (*H).
I emailed Bryan Carnathan, who publishes excellent reviews of canon cameras and lens on The Digital Picture web site. He replied a few hours later that he didn't have an answer, but he asked his Canon rep and this was his response:
I don’t have an EOS 7D or 7D Mark II on-hand to compare it with, but I think what’s happening is the infamous 2-second timer – that is, the metering timer that kicks-in AFTER a shot is taken – is cutting off locked-in ambient readings. This can happen with or without flash. (Incidentally, mechanical vs. 1st-curtain electronic shutter, and Auto Lighting Optimizer, should have no impact, AFAIK.)
First off, if the user has flash on the camera, turned on, and (with the AE Lock / * button at its default, factory settings), if it’s pressed with flash ON, you get Flash Exposure Lock – a low-power pre-flash fires once, THAT flash reading is temporarily locked into memory for 16 seconds, *and ambient exposure is free to wander if the camera is moved and ambient lighting changes.*
The interaction with flash and locking exposures IS DIFFERENT in EOS mirrorless cameras, but the following steps should let the user:
(a) with flash on-camera and turned on, lock-in an ambient meter reading (without Flash Exposure Lock pre-flash occurring), and
(b) keep that locked-in meter reading well after any shots are taken (remember, normally, any locked-in Ambient readings are held for only two seconds after the most recent shot is taken)
OK, all that said:
Change the AE Lock (*) function to: AE Lock with Hold (asterisk icon, with letter “H”):
Menu > orange Custom Functions menu > Menu screen #3 > Customize Buttons > select AE Lock button (or whichever button you want to use to activate locking ambient exposure) > Change to “AE Lock (Hold)”
This will do two things: allow you to lock AMBIENT exposure with one press of whichever activation button you’ve chosen, and then UN-LOCK ambient metering, if you want, with a second press. AND, most importantly, it does away with the 2-second time limit of keeping exposure locked, AFTER a shot has been taken. Now, you can press the button to activate ambient AE Lock, re-compose, shoot to your heart’s content, and take time in-between each shot, without the meter timer jumping in to try to clear your locked-in ambient meter reading from memory.
Adjust the time – AFTER a shot is taken, or after the last shot is taken – for the meter system to stay active, and keep a locked-in ambient reading active:
Menu > yellow Set-up Menu > Menu screen #3 > Power Saving > press SET button
With the following settings on my EOS R6 Mark II, I can lock ambient metering (again, using AE Lock with Hold – NOT ordinary AE Lock!); take my time and move the camera to other areas – exposure is locked-in at the initial shutter speed I’d read in Av mode at the first button press; Shoot any pictures I want; and the locked-in ambient meter reading stays active (little asterisk icon appears on LCD screen, or in viewfinder) for more than a minute:
- Screen dimmer – 5 sec.
- Screen off – 1 min.
- Auto power off – 30 sec.
- Viewfinder off – 1 min.
These are NOT specific recommendations; they simply reflect non-default settings I’d previously set for Power Saving, in my sample R6 Mark II. Again, with this, Av readings with flash are saved for more than a minute AFTER the last shot has been taken, without pressing any buttons after that last shot.
Similarly, at these settings, if I press the button for AE Lock (with Hold) and *don’t* take a picture, the readings are likewise held for a little over a minute, until the Auto Power Off kicks-in and the LCD screen goes black. This assumes, of course, that I’m not lengthening the time with various half-presses on the shutter button, to focus on things or whatever.
Please note: all the above by-passes the normal “meter timer” setting, in the red shooting menu (screen #8 > Metering timer)… this would take effect (flash on or not), if any AE Lock was by-passed – in other words, if you simply woke the camera up by tapping the shutter button half-way, with no AE Lock active (no “*” icon in viewfinder or on LCD screen).
I’m pretty confident this will give the viewer what he or she is looking for, assuming I understood the nature of their question properly. Again, it’s NOT the same as on previous EOS digital SLRs – it’s gotta be dealt with in a different way, and the AE Lock with Hold is a key aspect of this. Hope this helps!
