So I am really trying to shoot much more LF and wanting to hone my craft. Using the app Reciprocity Timer it will give you a bellow extension and calculate the stop difference based on the length of bellows you have extended. My question is: Do you measure just the bellow or do you also add the depth of the camera back as well. So in my case an Ebony 4x5 which is probably an addition 1 1/2-2 inches to the film plain. So for example if the bellows are extended 4.9" with a 90mm lens would account for 1 stop according to my app, but adding an addition inch and a half or so of the actual camera it would add up to a stop. So which do you use? Just bellows, or bellows and camera? Thanks.