Julian Thompson Posted April 15, 2010 Share #61 Posted April 15, 2010 Advertisement (gone after registration) Yep - you seem to have nailed that Jamie. That looks bang on. "Roberts calibration division (Toronto)" is up and running Quote Link to post Share on other sites More sharing options...
Advertisement Posted April 15, 2010 Posted April 15, 2010 Hi Julian Thompson, Take a look here M9 - coincidence at infinity. I'm sure you'll find what you were looking for!
marknorton Posted April 15, 2010 Share #62 Posted April 15, 2010 Julian, have you had any problems with the locking screw upsetting the cam position when you tighten it? I find that even with a washer, the cam tends to move when I tighten it. Quote Link to post Share on other sites More sharing options...
Julian Thompson Posted April 15, 2010 Share #63 Posted April 15, 2010 Yes Mark, I tend to keep a little downward pressure on the arm as I tighten the screw and that seems to do the trick but it is definitely something to watch out for that. Quote Link to post Share on other sites More sharing options...
Jamie Roberts Posted April 15, 2010 Share #64 Posted April 15, 2010 Yep - you seem to have nailed that Jamie. That looks bang on. "Roberts calibration division (Toronto)" is up and running LOL--thanks once more Julian! Quote Link to post Share on other sites More sharing options...
Guest mc_k Posted April 15, 2010 Share #65 Posted April 15, 2010 Julian, I am interested in where the idea for the graph came from. I see the basic idea is that one adjustment determines the slope and the other the intercept. I thiink this needs a source though. I'm not clear on what you meant by labeling the axes "focus rotate" and "rangefinder window travel"; I guess that means travel of the parts to get to true focus and to get to coincidence, respectively. The graph is great because it shows so many things visually: the back and forth of the procedure, back focus, front focus, hitting the lens stop early, focusing "past infinity," and a lot more. Assuming the rangefinder works like this, I think you could just plot subject distance vs. actual focus distance and get the same kind of graphs; these are the two things you actually measure when you do the procedure. Also you might as well make the origin "closest focus." The line through the origin with unit slope (dotted line) represents a perfectly calibrated rangefinder. I'm not disagreeing with anything you said, just looking for additional info. Quote Link to post Share on other sites More sharing options...
Julian Thompson Posted April 18, 2010 Share #66 Posted April 18, 2010 Julian, I am interested in where the idea for the graph came from. I see the basic idea is that one adjustment determines the slope and the other the intercept. I thiink this needs a source though. I'm not clear on what you meant by labeling the axes "focus rotate" and "rangefinder window travel"; I guess that means travel of the parts to get to true focus and to get to coincidence, respectively. The graph is great because it shows so many things visually: the back and forth of the procedure, back focus, front focus, hitting the lens stop early, focusing "past infinity," and a lot more. Assuming the rangefinder works like this, I think you could just plot subject distance vs. actual focus distance and get the same kind of graphs; these are the two things you actually measure when you do the procedure. Also you might as well make the origin "closest focus." The line through the origin with unit slope (dotted line) represents a perfectly calibrated rangefinder. I'm not disagreeing with anything you said, just looking for additional info. I don't really know where the graph idea came from - I just wanted to record visually what was happening for future reference. As you say the focus rotate is the action of twisting the lens for focus and the rangefinder travel is the movement of the co-incedent window in the rangefinder, driven by the cam in the lens throat off the lens barrel. Quote Link to post Share on other sites More sharing options...
Guest mc_k Posted April 19, 2010 Share #67 Posted April 19, 2010 Advertisement (gone after registration) thanks for the info Quote Link to post Share on other sites More sharing options...
Guest mc_k Posted April 19, 2010 Share #68 Posted April 19, 2010 off topic, but I've been led to believe the Bessa T has only one adjustment for the rangefinder, right on the back of the camera. Compared to two M8s and two R-D1s, this is the only camera that has been accurate right out of the box for me. Quote Link to post Share on other sites More sharing options...
jaapv Posted April 20, 2010 Share #69 Posted April 20, 2010 Áctually, the RD1 is a Bessa... Quote Link to post Share on other sites More sharing options...
Ario Arioldi Posted April 20, 2010 Share #70 Posted April 20, 2010 And Bessa T is a film camera, makes a lot of difference. Quote Link to post Share on other sites More sharing options...
mn4367 Posted April 23, 2010 Share #71 Posted April 23, 2010 Áctually, the RD1 is a Bessa... No. They may share some parts or maybe many parts, but one is film one digital. Really not the same camera. Quote Link to post Share on other sites More sharing options...
jaapv Posted April 23, 2010 Share #72 Posted April 23, 2010 Hmmm...In my eyes it is a Voigtlander with the film replaced by a Nikon D70 sensor and a few digi add-ons, albeit retrostyled. Surprisingly it turned out to be quite a nice camera. Quote Link to post Share on other sites More sharing options...
Stealth3kpl Posted April 23, 2010 Share #73 Posted April 23, 2010 Is this infinity adjustment something that can be carried out in Milton Keynes? I ask because I'm considering sending mine away as it is under warranty. Pete Quote Link to post Share on other sites More sharing options...
jaapv Posted April 23, 2010 Share #74 Posted April 23, 2010 (edited) There are three points of adjustment in that arm. The hex excenter, the screw excenter, and the "waist" with the hole in the middle. That hole takes a bending tool, to bend the arm. Now these three play together to get the focus correct. Basically: adjust the hex for infinity, adjust the screw for close, and bend for intermediate. Return to hex, adjust infinity again (it will be off), adjust close,bend etc. and repeat that between three and five times to get a converging tolerance series. Now if you are prepared to do that - good luck to you.... Edited April 23, 2010 by jaapv Quote Link to post Share on other sites More sharing options...
Guest mc_k Posted April 23, 2010 Share #75 Posted April 23, 2010 Hmmm...In my eyes it is a Voigtlander with the film replaced by a Nikon D70 sensor and a few digi add-ons, albeit retrostyled. Surprisingly it turned out to be quite a nice camera. partly made at Cosina, but I thought finished at Epson. I don't actually know. But my current RD1 was adjusted at Epson Japan. Quote Link to post Share on other sites More sharing options...
mn4367 Posted April 23, 2010 Share #76 Posted April 23, 2010 (edited) Hmmm...In my eyes it is a Voigtlander with the film replaced by a Nikon D70 sensor and a few digi add-ons, albeit retrostyled. Surprisingly it turned out to be quite a nice camera. Yes it is a mainly a CV product but inspired by Epson. But I think saying it is a Bessa is a little bit like saying the M9 is a M7. Both digitals inherit some things from their analog sisters, but both are more than just derivatives. Completely unique characters (see the beautiful top plate controls on the R-D1). And yes you are right, the R-D1 is a wonderful camera, I had/have a lot of fun with it. Still a very competent instrument today. I wish the M9 had some of its features. Edited April 23, 2010 by mn4367 Quote Link to post Share on other sites More sharing options...
mn4367 Posted April 23, 2010 Share #77 Posted April 23, 2010 partly made at Cosina, but I thought finished at Epson. I don't actually know. But my current RD1 was adjusted at Epson Japan. Apart from the digital imaging components I'm quite sure it is completely build and (behind the scenes) serviced by Cosina. Interestingly I heard by someone from Leica that Epson first tried to partner with Leica to bring out a DRF. But this joint venture didn't happen as we all know. The guy didn't tell exactly the reason for it, but between the lines it was obvious that a) Leica already was on the road to the M8 or they thought at that time that the result wouldn't be up to their quality demands. I think it was quite early so maybe was the reason. Or perhaps c) they didn't want to be the Cosina for Epson. Quote Link to post Share on other sites More sharing options...
jaapv Posted April 23, 2010 Share #78 Posted April 23, 2010 Yes it is a mainly a CV product but inspired by Epson. But I think saying it is a Bessa is a little bit like saying the M9 is a M7. Both digitals inherit some things from their analog sisters, but both are more than just derivatives. I would say the RD1 is a lot closer to the donor camera than the M8 is to the M7. On the Epson the dimensions are unchanged, the shutter is the same, even the "transport mechanism" is a direct descendant from the film parent. On the M 8 the body size and shape are changed and all the internals except the rangefinder. In fact, that is a whole new camera. 1 Quote Link to post Share on other sites More sharing options...
jaapv Posted April 23, 2010 Share #79 Posted April 23, 2010 Apart from the digital imaging components I'm quite sure it is completely build and (behind the scenes) serviced by Cosina. Interestingly I heard by someone from Leica that Epson first tried to partner with Leica to bring out a DRF. But this joint venture didn't happen as we all know. The guy didn't tell exactly the reason for it, but between the lines it was obvious that a) Leica already was on the road to the M8 or they thought at that time that the result wouldn't be up to their quality demands. I think it was quite early so maybe was the reason. Or perhaps c) they didn't want to be the Cosina for Epson. That is an interesting post. Many people assume Leica was forced into the M8 by the appearance of the RD1. I always doubted that as that would presume a quite short development period, and your post confirms that impression. 1 Quote Link to post Share on other sites More sharing options...
Julian Thompson Posted April 24, 2010 Share #80 Posted April 24, 2010 There are three points of adjustment in that arm. The hex excenter, the screw excenter, and the "waist" with the hole in the middle. That hole takes a bending tool, to bend the arm. Now these three play together to get the focus correct. Basically: adjust the hex for infinity, adjust the screw for close, and bend for intermediate. LOL! Care to illustrate just how bending an arm in the middle can affect anything in an eccentric fashion to re-adjust mid focus independently of close and infinity then Jaap? Because I'm all ears for this fascinating re-write of the laws of mechanics. Quote Link to post Share on other sites More sharing options...
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