I have a client who is having me produce a promotional video. I bill this client hourly for work I perform for them. As the video nears completion, it's getting to the point where it takes 15 minutes to render out the full sequence in HD.
How do I bill the client while my computer is rendering? At first I was thinking of charging them a reduced rate, since once the render starts I can just throw on the TV for 15 minutes. However, since I can't perform any other work for any client while my system resources are committed to rendering, I'm starting to think it makes more sense just to bill at my normal rate. Is there a standard practice for this?
(I am not trying to fleece the client; I typically only do a full render once per full day of work - that's 15 minutes out of 8 hours spent rendering.)