I downloaded to my Pocket PC the DOF calculator from LF website. It is very good but now I am trying to figure out how many lines per mm I need to get a crispy image at the final print. There I need some help:
Let us say that I am shooting in 4x5 and the final print will be 30 x 40 cm (10 x 16 inches). Prints are supposed to be viewed at 50 cm (20 inches) distance. The subject is a good one to demand a sharp rendering. It has textures and well defined edges. Then I have two questions: for the area "in focus", what is the average lines per mm definition for a print in that situation that would make a crispy look to the average human eye? and second: As I am enlarging roughly 2.3 times the neg, is that correct to take the answer to the first question and devide it by 2.3 in order to assess (at the shooting phase) the definition in lines/mm I need in the negative and foresee what is going to be in focus in the final print using the DOF calculator?