As i am posting a request for help for the restoration of the camera that came with it, i take the chance for an inquiry about the construction of the lens.
Unfortunately my Ilex Photoplastic 5x7 came with a standard, non inscribed, back cell.
I know that a few other users have the same lens, with different cells.
What's the difference between the three different types?
I am asking about it because i had the guess that it could just be a different "optimization" (read: spacing) of the cell.
Maybe not... but worth asking
The idea came to my mind after deciding to "turn soft" a nice 12" f/4.5 Ektar (black, uncoated, on Compound shutter). If i find a rubber ring of the right size, i'll try to unscrew the front element, and re-seat it after placing a shim that would distance it a little more from the second glass element. Still unsure about the width of the shim: is 1mm enough, or still too little to get a very visible "soft" effect?
I am asking because i have experimented with a similar Tessar design, a Schneider Radionar 105mm on Prontor shutter, with front lens focusing. Setting the front lens at min. focusing distance (that's probably more that 1mm difference from infinity) isn't causing a strong softening of the image. I have to retry wide open, though.
Any infos about the Photoplastic back cells?
Any advice about my 12" Ektar project?