Light Leaks

I'm building two rooms in an unfinished basement. The rooms will be about 9' x 5' each. There is no ceiling per se, only the subfloor and floor joists for a ceiling.

The walls will only go to the bottom of the floor joists overhead so there will be many light leaks between the top of the new wall and the space between the bottom of the floor joists and the subfloor above.

There is also ductwork, plumbing, and wiring that I have to work around to plug the light leaks.

I don't want to build a ceiling for various reasons. Anyone have any good efficient ideas of how to plug all these irregular holes?

Thanks.

Staple gun, duct tape, and a shit load of panda film should do it as a mock ceiling. It will be reflective, easy to rip down when ever you need to, and should only cost about 10$

https://www.rollitup.org/indoor-growing/406649-l-woman-4th-grow-first-2.html#post5285037

My setup in unfinished basement. In same boat have most filled though boards and caulkm weatherstrip, duct tape etc

Expanding spray foam is your friend. $4.00 a can at Home Depot.