Hey! I think that with some modification it would be possible to either render black as transparent or use the input image alpha, but due to the way the entire process is set up (including the use of camera lens blur) I guess the results wouldn't exactly be clean, and would require lots of internal rewiring to get it running properly. Maybe just mixing the shader result with a transparent shader using the input image alpha would be enough? I just never thought about including transparency into my CRT emulation processes since it usually involves rendering an entire display at once :D