Lens that doesn't focus.greenspun.com : LUSENET : Large format photography : One Thread
I have a Caltar 90mm, f6.8-45 in a Cambo mount for Calumet NX monorail. I cannot get it to focus. Whether up close, 4 feet say, or focussing at a distant object, 25 feet say, the image remains fuzzy. The effect reminds me of unfocussed images in a microfilm reading machine, when the film has not been spooled correctly between the glass-sandwich guides. Can anyone suggest what might be amiss?
-- John McCallum (email@example.com), October 06, 1997
You might not be collapsing the bellows sufficiently. I had what may be the same problem with a Rodenstock 90mm f6.8-45 on a Wisner Technical Field. Ron Wisner advised that the solution was to use either the front or rear base tilt to further compress the bellows and then use the axial tilt to return the tilted standard to vertical.. Doing this allows one to compresses the standard Wisner bellows more than an inch beyond the conventional adjustments. Can't speak to whether this will work on a Cambo. Good luck.
-- Dick Silven (firstname.lastname@example.org), October 12, 1997.
Many times when using short lenses on a monorail camera, you will need to place both the lens and film back units on the same side of the tripod block.Some of the tripod blocks are too wide to allow focussing with these lenses when the camera is set up normally, that is, with the lens unit on one end, the tripod block in the middle, and the film back unit behind that. Check your camera instruction manual.
-- Tony Brent (email@example.com), September 09, 1998.