Crown/Speed Graphic cams: are they really customized to a particular lens?

[Jerry Thirsty]

Hey folks,

I've got a Crown with top-mount rangefinder and the Xenar 135mm. The rangefinder seems quite accurate compared to the ground glass, but the Xenar is quite soft in the corners. I'm thinking of replacing it with a more modern 135mm (possibly a Fujinon-W). Assuming the actual focal lengths of the two lenses differ by a few mm, will I really need to make a new cam for the new lens, or can I eliminate most of the error just by resetting the infinity stops? Or will a difference of 2-4% show up as focusing error much more readily than I'm assuming? (FWIW, I don't print any larger than 16"x20")

thanks,
Jerry

 

[Denis P.]

I made a couple of my own, no big deal - mostly for relatively wide lens (one was for a 90/8 lens...). They are not suited for ultra fast lens (with very shallow DoF), but are close enough "for Government work"

BTW, you can test the setup yourself: put on the new lens, put it on "T", and, after focussing using the rangefinder, check focus on the ground glas. Easy

It will tell you all you need to know. If the RF and GG do not match, you'll need another (custom-made) cam.

Rgds,

Denis

 

[Jerry Thirsty]

Well, I have a Sironar on the way. It might get here in time to try this weekend. I decided to pass on the Fujinon, because I couldn't tell whether the front cell is short enough to allow the camera to close.