Originally Posted by m. dowdall
As I said to Dave, if you will tell me what film/developer you plan to use I can probably suggest a develoment time that will give a good negative for printing in carbon.
If you are using a traditional non-staining developer just take the reading in Visual channel, and shoot for a DR of about 1.5 - 1.7. If you develop with a staining developer the Blue channel reading will be quite a bit lower than effective printing density. However, a Blue channel reading of about 1.3 will translate into an effective UV density of around 1.6-1.8, depending on developer.