PDA

View Full Version : Adjusting focus screen on R.B. Graflex D series 4x5



RawheaD
24-Feb-2012, 11:32
Hi all,

I recently got an R.B. Graflex which I converted the back to a Graflok back using the adapter made by Bert Saunders. After my first shot, I realized the camera is front focusing (I don't think it's due to the conversion... it must've been off from the beginning).

http://flic.kr/p/bxJAcF (I focused on the face, actual focus is around the hand).

So I'm guessing I need to adjust the location of the ground glass screen inside the chimney. Can anyone tell me how this is done? Thanks!

Jon Shiu
24-Feb-2012, 11:39
You can get to the ground glass by swinging up the chimney. There is a small spring clip in the front holding the front of the chimney.

Jon

Jim Noel
25-Feb-2012, 07:33
I'm guessing that teh padding under the mirror has disintegrated throwing the focus off in relation to the film plane.

rjmeyer314
27-Feb-2012, 07:27
The simple way to do this is to put a graflok back with a focusing ground glass on the back. Focus an image on that. That will give you the correct focus location for the lens. Remove the focusing hood. Loosen the ground glass that was in the hood and put shims under it until the focus is correct (you'll probably need to use a loupe to get it just right). You'll be able to see the image well enough to do this without the hood in place. Then refasten the glass, making sure you retain the sharp focus. While you're at it, you may want to outline the image limits on the ground glass in the graflok glass in pencil on the glass in the focusing hood. That way you know what will be included in your images.