kalart rangefinder adjustementgreenspun.com : LUSENET : Large format photography : One Thread
I have some problem adjusting the Kalart rangefinder on my graflex. I followed the instructions I found on the web, including the so-called undocumented one about the screw under the prism and here is the problem: my rangefinder was way off off so after setting the 15 and 4 ft to standart I set infinity with the screw under the prism. this worked. now the problem is that changing the 15 ft scale does'nt seem to change the images in the rangefinder. I have taken the whole plate down and everything seems to me OK, moving and working. any proposition? the only part I cant realy check is the contact between the metal arm moved by focusing and the rounded part on the sliding scale for 15 ft.
any help will be highly appreciated.
-- Michael Hassoun (email@example.com), October 07, 2000
Hi Michael, I too have had no luck with my Kalart after WEEKS of constant adjusting and fiddling. I think I've tried everything and just don't use my Graflex for anything spontanious anymore. Strictly ground glass focusing. If anyone out there could give a few tips would be much appreciated.
-- Ted Davis (firstname.lastname@example.org), October 07, 2000.
Can you tell if your cam arm has slipped off the track? I assume this is the side mounted model. There is a shaft that goes through the camera body, and then an arm that goes down to and engages the track that slides back and forth with the focusing knob on the front rail. I think my once came off the track and caused similar problems. Basically as you twist the focusing nob back and forth, the rail will go back and forth, and then you should be able to see that arm move back and forth. If you don't see that, that could be your problem.
-- david clark (email@example.com), October 07, 2000.
A while back, I expended quite a bit of effort trying to optimize my Kalart. I was mostly successful. I don't have a definitive answer for you and I don't have my Crown in front of me, but I feel your pain, so I offer the following from memory in the hope that it might be of some help:
First, note that the rangefinder arm that contacts the eccentric on the bed is connected at the other end to the actual rangefinder pivot (the post going through the body) by - if I remember correctly - a couple of (allen?) screws. I found that in practice, if these screws are not super tight or the arm is given a good bump, the arm can "slip" and put the rangefinder out of adjustment. Nothing surprising there; what followed in my case is that I adjusted the rangefinder internals per the instructions on Graflex.org, without recognizing the misalignment of the arm. I found that the altered arm orientation can put the rangefinder at or near the limits of its adjustment and accuracy. This is manifested as either an inability for it to reach image alignment or non-linear behavior (don't ask me to prove this or explain why - purely anecdotal evidence). You'll know this situation because you get almost there in terms of adjustment, but can't figure out 1) why every setting is so different from before, 2) why it still isn't spot on, and 3) how it got so damn dark outside already. If this describes your situation as well, try getting everything back near the way you found it, then readjust the arm to a position that puts the travel of the internal rangefinder mechanism mid-range for the range that the bed can be racked in and out. Don't forget to put the bed mounted eccentric in a mid-adjustment position as well; it works best as a final fine tuning mechanism, in my experience.
David also makes a good point about checking for smooth movement of the arm. It can get caught up against the cable routing for the body release, or, with the slippage problem I described above, it can completely cease to move once it has reached the Kalart's range of pivot, even though the bed is still going outward.
Unfortunately, you may in practice have to compromise a bit. I adjusted for maximum accuracy in the closer distance range (i.e., images don't exactly coincide at confirmed infinity focus), knowing that depth of field would be more critical in these situations. Well, I also kind of hoped that I would generally know infinity when I saw a reasonable approximation of it.
Hang in there. It's definitely an iterative adjustment process. And feel free to email me if needed.
-- Richard Koo (firstname.lastname@example.org), October 13, 2000.
Online reproductions with instructions and pictures of the original graflex instructions for adjusting the rangefinder can be had for free at www.graflex.org. Alternately, you can pay 5 or 6 bucks for a terrible xerox in which the pictures are USELESS of these instructions from www.mpex.com --- I bough the instructions from MPEX, was deeply dissapointed and then found the online manual.
-- stephan (email@example.com), October 14, 2000.