
Posted: Mon May 17, 2010 6:20 pm
1. Check your film holders for correct film placement depth.
http://home.earthlink.net/~eahoo/page8/filmhold.html
Remove the dark slide, put a sheet of film in the holder, lay a straight edge across the holder and measure from the bottom edge of the straight edge to the surface of the film. It should be equal depth across the width and length of the holder. Check both sides of all your film holders. I have had holders with one side off.
2. Remove the complete camera back. Graflex used different diameter and different length screws to hold the camera back on so note their original position when removing the screws. An improperly placed screw can damage the camera.
Standard ground glass placement measurement
With the camera back off, insert a film holder with a sheet of film installed and the dark slide removed. Lay a straight edge across the camera back frame making sure that the straight edge does not sit on a high bump on one side (all camera backs are not even around the edge), and measure from the bottom of the straight edge to the film surface. Record the measurement. Check the distance at several places, they should all be the same.
Next remove the film holder from the back and measure to the surface of the ground glass. It should be the same distance you recorded for the film. Shim the ground glass so that it sits at the film plane if it is too close; mill the frame edge down if it is too far away.
With the fresnel in front of the ground glass you have to add the thickness of the fresnel to the measurement to get a correct reading.
A focus panel factory equipped with an Ektalite Field Screen (Graflex speak for fresnel) will have short bosses that the ground glass/fresnel sandwich sits on.