90mm KL, One problem down, one more to go

[paul_ong1]

<p>Hi,</p>

<p>As some of you know, I have a Mamiya KL 90mm that was extremely soft. Many here were helpful with suggestions, including that the lens elements could have been incorrectly assembled. I finally tracked down a lens diagram to check whether the individual lenses were properly assembled.</p>

<p>Surprise, the second to the last element in the rear cell was in backwards! I cleaned and reassembled, and now the softness has gone away.</p>

<p>My next step is finding an aperture because the adjustable iris diagram is missing. I think my strategy will be the same, that is to find a broken lens and transplant. </p>

<p>Does anyone know if the the older and newer apertures are interchangeable? I certainly will try MAC, but I think they may be getting tired of me asking so many questions without buying anything.</p>

<p>I am attaching the KL 90mm diagram for others who my find it useful in the future.</p>

<p> </p><div></div>

[jim_krupnik]

<p>Keep a close watch on the KEH site for the same vintage lens in the "as is" department. I picked up some dead RZ and Bronica PS lenses in otherwise "EX" condition there for just a few Dollars. If you enjoy peeling apart broken gear, it won't be long before you own several fine lenses with different troubles for less than the cost of shipping, and end up with a great working model in the end.</p>

<p> </p>

[andre_noble5]

<p>Just a comment: Looking at the diagram, it seems like it would be a pretty obvious error for someone to reverse the secong to last element - as in the lens was reassembled by a person who was very sleepy at the time, lol.</p>

[david_mcniven]

<p>Hi all.<br>

Paul, you know the diaphragm is at the bottom of the shutter and some work will be needed to fit it? You'll also need the shutter (casing at least) and control links between the aperture ring and the diaphragm. Not certain about differences between versions - only had one on my bench at a time. My guess is they'll be interchangeable though.<br>

Jim, thanks again for the manual!</p>

 

[paul_ong1]

<p>Jim, I have now taken apart and reassembled (or partially reassembled and modified for the hybrid camera) over a half dozens lenses. I am still learning how to do this efficiently and precisely. The forum has been very helpful.</p>

<p>Thanks for the KEH suggestion. I now have an "as is" link in my bookmarks so it is easy for me to check every day. It took me a few tries to learn how to use the search function effectively. I wonder how often KEH refreshes its "as is" inventory.</p>

<p>Andre, perhaps a sleepy previous owner. However, that element is in a removable sleeve that can house the lens in either direction. If a person does not carefully document each step or has a diagram or manual, it is easy to make the mistake. In fact, reversing the lens seems to fit the sleeve better.</p>

<p>David, yes learned that when I disassembled the non-C 90mm and the 180mm. I have gotten to the diaphragm both times. (I see I misspelled the word "diaphragm" in my original post.) I have been able to remove it and reinsert it. One time, it fell apart, so I had to learn reassemble the blades. That takes a bit of time and effort.</p>

<p>I will be looking for a very broken Mamiya lens with a functional aperture diaphragm.</p>

[steve_rasmussen]

<p>Paul, thanks for including the cross section. It doesn't exactly fit into any established reversed telephoto design type. A double negative meniscus up front like a Wild Aviogon and a middle and rear group similar to the original French Angenieux design that they called "Retrofocus". The 90 KL is unique.</p>

[paul_ong1]

<p>Steve, thanks for the info. Many new terms that I will have to look up.<br>

I also made a better image of the KL 90mm diagram (along with pre and post example of photos using the lens) and posted at:<br>

[steve_rasmussen]

<p>Thanks Paul. Hard to believe that Mamiya had such a flawed assembly process and also did not check the finished lens performance. If they had, they surely would have caught this problem.</p>

[paul ron]

<p>Now hold on there Paul, that's enough of this "preious owner" garbage.</p>

<p>I've stood back n bit my tongue as you keep refering to the "previous owner" with each n every problem you're having with these lenses. That sleepy "preious owner" was me... again n again n again. I had enough standing by as you keep refering to the "previous owner" as if he were inept with each n every lens you have problems with. But yet, with all your years of working on these lenses n RBs you must be an expert n had nothing to do with causing any of these problems?</p>

<p>It seems from the start, you suposedly got those lenses with smashed decorator rings n had to cut it out because of shipping damage... IMPOSABLE! You have no idea how to properly remove the rings n smashed em when attempting to remove em improperly, as an amature might do. They were carefully packed in bubble wrap just as I have done for years n sent em all over the wold without ever having problems... you are the first in all my years. In fact, I loosened those rings so you wouldn't have any problems getting em out as well as partially dissasemble them to make your job easier. Blame the "previous owner?"</p>

<p>Then you say the flaoting lens had a problem because the "previous owner" must have screwed it up. That is obsurd! That lens was opened for inspection then closed without altering anything. In fact that lens was in Mint Condition, just had a bad shutter, a broken plastic gear axle. "Previous owner" again? You have no idea how a floating lens worked n screwed it up taking it appart, a typical amature mistake Paul, we all understand that. But "previous owner" again?</p>

<p>Then the iris is missing in that lens beacuae the "previous owner" must have fooled with it. AGAIN Paul? WHY? That is imposable, the iris is built into the shutter n that shutter was never taken appart, just looked at for damage. Did you open it it up n just can't admit all the leaves fell out n you can't get em back in properly? "Previous owner again?"</p>

<p>The element in the lens was put in backwards by a sleepy "previous owner?" You really are full of crap now! Did you open the cells Paul? Only an amature would do that. SO why blame the "previous owner" again? Does it make you look stupid if you admit doing it yourself? Another amature mistake?</p>

<p>Was that shutter really rusted Paul? "Previous owner" again? WHY would it rust?.. I had that lens stored with my working cameras and not one of em is rusted or water damaged. I don't have water problems in my house Paul I don't live in the rural wetlands of NYC. Sheesh that takes it all buddy boy!</p>

<p>Why don't you tell us about all the experiance you have with lenses n RBs n camera repairs?</p>

<p>Stop insulting me as the "previous owner?" YOU are the cause of these problems n shirking it off as the "previous owner" because you have no freakin idea what you are doing n no balls to admit you made a mistake! . .</p>

[paul_ong1]

<p>Paul Ron,</p>

<p>I don't mean you. My understanding is that you got the broken lens from another owner, so I am referring to the original owner. I am truly sorry that I was not clearer on that. I really do not mean any disrespect to you. In fact, in earlier posts, I went out of my way to thank you to providing the lenses.</p>

<p>I am total in error in my wording in using "previous owner" rather than "original owner", and I take all blames.</p>

<p>As for the problems, no I did not open the cell before. I only opened up once to check to see if the lens was backwards, as suggested by another poster, and only after I got a diagram to check how the lens suppose to be placed. As indicated in my earlier posts, I usually do not start disassembling until I have some diagram, which I have requested from other posters.</p>

<p>As for the iris, yes one it was missing. And yes, on one of the other lenses, the blade assembly did come apart, but I was able to put it back together. A good learning lesson.</p>

<p>I do share my experiences with the goal of providing information for any future reader. One of my frustration is not finding enough information on the web, and when I do find information, I am very appreciative that the posters were willing to do that as a service. I thought I would return the favor. However, if it is not useful, I certainly will stop.</p>

<p>So, my apologies for my offenses.</p>

[paul ron]

<p>So you are saying that when I checked each n every one of those lenses I missed all the problems you've complained about? How long have you been repairing these lenses? They only needed shutters n reassembly when they left my shop!</p>

<p>Is this the first time I've ever looked inside a lens? I had to bite my lip each n everytime you came up with another problem blaming someone else. Again, you are insulting my intelegence.</p>

<p>Just move on Paul.</p>

<p> </p>

[paul_ong1]

<p>For those interested in updates on the Mamiya-Toyo-Nikon hybrid camera, you are invited to check the link below. I will try to update once a month. My goal is to share the experience for those who want to pursue something similar so not to repeat what I learned through trial and error, and to receive input and ideas from others.<br>

http://www.flickr.com/photos/9476880@N02/sets/72157621949266496/<br>

Paul Ron, again I am sorry that you feel insulted. I am an amateur and have no problem stating and admitting that make mistakes, which happens often as a part of the learning by doing process. That is why I seek help and assistance, and when I do so, I try to be as accurate and precise in describing the situation. It is impossible to document what is not present (the aperture), although I can document what is there (the rust). But I think that is moot. Best of luck on your photographic efforts.</p>

[charles_sharp2]

Paul

 

The Rollei / Mamiya Store on Ebay has new shutter assemblies for RB lenses for 29.99. I think this may be the item you are looking for

 

Good Luck!