Showing previously taken image on screen during long exposure

[dmilligan]

I like to have it on the whole time, but that's just me. I usually use an AC adapter or a battery grip. I may go to check on things and it's in the middle of a 2-4min exposure, I don't want to stand there waiting for 2 minutes until the screen comes back up. However, I wouldn't be opposed to having a time setting for this, like the canon menu: 2, 4, 8, 16, or always on. Though I think you'll be suprised how small an effect it has on battery life. I've shot with this turned on for several hours on a single battery (screen brightness to minimum). That's on a 60D though, I'm sure the FF sensor of 5D3 is more power hungry. If you're really concerned about battery life then simply disable this feature.

Maybe some other ML or canon settings effect whether or not this works (raw histogram on image review maybe?). I will do some futher testing.

[RenatoPhoto]

Global draw off.... no change
Image review off ... I dont get any preview, not  even on the first image on 5D3.

[dmilligan]

It seems as though display_on() or display_off() doesn't like to be called more often than once per 30 seconds, at least on my 60D. So if I use a bulb time less than 30s, display_on works the first time, works the second time, then the third time the screen does not come back on.

Everything works flawlessly on the 1100D, even for shorter bulb durations.