My first large-format portraits did not use diffusion. What a mistake! The pictures revealed pores and hair on people's faces that were not evident in real life. It was like looking at their skin under a microscope. Now, I feel that all large-format portraits need some diffusion, unless the goal is to emphasize the texture of the subject's skin. I am not aiming for maximum sharpness by using large format, but smooth gradation, which the larger number of grains allow. It is like using a 1200 dpi printer instead of 300 dpi..(posted 8637 days ago)