Making black transparent

I usually use a keyer to get rid of background colours, but earlier today i tried to get rid of a black background, and instead it turned the whole thing transparent. Is there a way around this?

I think i might have found the answer! I’ll keep this thread updated!

Just found my own solution! However, answers would still be appreciated if you can suggest any other ways!

Try the basic Keyer node in luminance mode (if the background is black, set center to a low value)