Greetings - Is the exposure time for carbon transfer similar to that of Pt/Pd? If not, would carbon take 1/2 the time, twice the time, etc using the same negative? I'm using a bank of 8 F20T12/BL tubes about 4.5 inches from the contact frame for Pt/Pd. I'm trying carbon transfer for the first time, and I just hate having to figure out a starting exposure time. I just need to be in the ball park somewhere to start with. Thanks in advance.