Remembering locked white balance, better "manual mode"

[peter gervai]

I'm not sure this forum works as intended but it's polite to try first.
I have been fighting with white balance for years and now I think I'll voice my pains.

Manual white balance uses - I guess - a simple white point setting, which (for me) turned out to be useless. It is probably good between sun and incandescent but does not good for real-life usage like having proper colors. (I cannot set it to have green greens on a sunny day.)

Usually I can force OpenCamera to have a proper white balance by pointing at a white paper and locking WB. It is not the best, since it would be better to have a "Set WB manually" setting, which specifically used center to get WB, but it usually works by some extent. Locking it works more or less well. Colors can be real.

HOWEVER, lock is cleared by entering menus, by switching off phone screen, or changing apps.

It would be nice, if:
- locked WB could be stored, and retrieved; possibly even named, since most of them are quite repeating (and hardcoded states [probably from the API2] do not seem to be very useful)
- if not, would be great if WB lock would stay locked throughout hardships of life (phone suspend, app change, entering menus, ...);
- maybe if there were separate "manual WB detection" and a "manual white temperature" menus, it would be most logical and useful.

I hope this have some merits.

Thanks.

ps: I should try raw, but, well, it's a pain for normal everyday shooting. And I'm not even convinced raw is real raw.

[Mark]

That makes sense. There are two reasons why this isn't straightforward:

• White balance lock in the Android API is a separate feature to manual white balance, and doesn't offer the ability to remember after restarting the camera.
• The space of possible white balance values is 3D, but in manual mode this is compressed to a single value (as is common in camera apps). So although Open Camera tries to select the closest when switching from auto to manual white balance, it won't be a direct match.

It is on my TODO to add support for the full 3D manual white balance, which might help with this.

[peter gervai]

What do you think about getting a manual white point (using the camera pointed at a white target) in the 3D space and storing it, instead (or next to) the android WB detection?

Detecting white balance from the middle area probably doable and easiest to store since it's yours, not android's. And doesn't require you to come up with a GUI for 3D entry. :-)

(I found several pretty good sounding auto white balance detection algorithms as well while searching for my thoughts; if you'd detect the wb yourself you'd have the quotients. But it'd cause some code bloat and feature creep. I'd find it very useful [probably way more useful than a manual 3D entry], but I may not represent the majority of the users.)