Thanks Jim for your input and observation.

I have the Portrait 3-A mounted and I'll check the close-up scenario next time I'm working with the camera.


Quote Originally Posted by Jim Graves View Post
The Vade Mecum speculates the Portrait 1-A diffusion adjustment was mainly effective for close-up portraits:

The separation of the rear glasses was adjustable to control softness, and this may be most useful in close-up as it increases the depth and eveness of definition.

I have Mr. Galli"s 9" 1-A (intended for 4x5) ... I have only shot it close-up on 8x10 for flowers and still life. When diffused and re-focused the effect is very subtle.