Have and use a 12 3/4" f/7.7 BL Protar V11 lens on my 11x14 (front and rear cells being 18 7/8” and 27”). Have only once used the 27" cell alone... unfortunately was on a very windy day and the bellows acted like a sail and the exposure had just too much movement to even be contact printed. Have read that when using the front or rear cells alone, using a yellow filter is recommenced. Also there is some focus-shift? Looking for hands on experience with using the front or rear cells of a Protar alone.
thanks...