ETTR in recent builds is not usable in low light.
I used to shoot a lot of timelapses before 4K video era begins.
I even shared my hard earned settings for getting amazing sunrises:
https://www.magiclantern.fm/forum/index.php?topic=18730.msg178621#msg178621Recently i tried to shoot timelapse with recent build and failed.
Now i try to sort out whats wrong. What i found: as long, as i reduce light, the image on LCD gets more pixelated,
histigram shows overexposure, ETTR shortens exposure(!!!), but screen gets only brighter and brighter and, finally complete white.
It saves completely black DNG, of course.
I compared the ettr source of recent build with the old one.
I found suspicious new code:
if (overexposed_percentage > 0 && (auto_ettr_midtone_snr_limit || auto_ettr_shadow_snr_limit) && !dual_iso)
I enabled DualISO, to test, whether this is the source of problem - and it disappeared.
Instead of white screen I gets correctly exposed images with several second exposures.
I decided to comment this out and try without DualISO - problem persist.
DualISO fixes the problem somehow, but that code is not the source of it.
So, i stuck on it, have no more ideas, my humble skills don't allow me to find why it used to work but no more
