Hi everyone, I am a concept film photographer and I'm looking to create some different patterns in Photoshop to project onto a backdrop. I'm wondering what the easiest way is to create a pattern that doesn't have a background that would be projected. For instance, I want to project a large rectangle onto a white backdrop to simulate a doorway, but I just want the door projected, not anything else like a black or white background
Depending on your end file format PNG preserves transparency.
You could create your backdrop using layers with transparency and save out to that format.
Thinking back on your last part - transparency will still project white coming from a projector.
If you are trying to map and image to a specific area and not have light come from the projector, you should look into some of the projection mapping softwares on the market. It can create custom mapped areas for projected images.
Do you understand the concept of light projection?
You can project light (of different brightness, color, …) but you cannot project »black«.
No I'm not an expert in light projection lmao so ur saying that if I set everything I don't want to see as black then it will only project the parts I do want?
But of necessity that means the projected elements are lighter than the parts where nothing (black) is projected.
What you described (door on white background) would seem to necessitate a different approach, namely projecting a whole lot of white with a dark rectangle (or whatever) for the door.
Whether that makes sense in the actual set-up is up to you to figure out.