I am thinking about getting a 75mm lens for my enlarger so that I can do medium format as well as 35mm. Assuming that the thread sizes on the two lenses are the same should I also get a second lens board?

-- Peter Schauss (schauss@worldnet.att.net), February 20, 2002

Answers

Most Beseler lensboards I've seen are not threaded and just have a "through-hole". To mount the lens you need to add a jam nut.

Thus, 2 separate lensboards is easier with normal mounting.

But, Nikon, and others, make a short lens extension (about 15mm if memory serves me) that is threaded to accept lenses (39mm threads). You could mount this on the lensboard, then screw on/off lenses, assuming the same thread size. It would limit your maximum enlargement size, though, but it might not be important to you.

-- Charlie Strack (charlie_strack@sti.com), February 20, 2002.

It makes sense to buy or make another lens board, as they just snap in and out. Much less fuss than fiddling with the jam nut every time you want to change lenses.

-- Conrad Hoffman (choffman@rpa.net), February 20, 2002.

I have a 23C and use 2 lens boards for 2 different lenses and it makes it quite easy to change formats and yes, as noted you need the jam nut which does not come with the lens or lens board. I would caution you that 75mm seems pretty short for medium format, you might want to check into this. I print 6x4.5 and use a 90mm Rodenstock lens to get enough coverage.

-- Mike (watgo@aol.com), February 22, 2002.