carlos.paula Posted May 17, 2014 Share #1 Posted May 17, 2014 Advertisement (gone after registration) I have a very nice (cosmetically) 90mm Collapsible, but unfortunately with its front element very scratched. I found a bargain lens Elmar 90mm (non collapsible) to buy. Anyone knows that the elements of these two versions of Elmar 90mm are the same? Perhaps I would to change the bad element of my collapsible by other in this cheap lens. Thanks a lot. Link to post Share on other sites More sharing options...
Advertisement Posted May 17, 2014 Posted May 17, 2014 Hi carlos.paula, Take a look here Elmar 90mm Collapsible. I'm sure you'll find what you were looking for!
luigi bertolotti Posted May 17, 2014 Share #2 Posted May 17, 2014 I fear that the answer is of the kind "yes, but..." The collapsible Elmar has the SAME lens schema of the previous Elmars (4 elements, of course, though the collapsible was made after the intro of the Elmar 90 3 elements) , so, in theory the rather simple Elmar Group ought to be interchangable... but is it really so, in practice, supposed one finds a good lab to perform the transplant ? Surely Leitz, at that era, didn't perform this as a factory service... I doubt that a lab can guarantee you of the result. I have just checked my Elmar collapsible and my Elmar BM E39 ... front element looks the same in curvature, and also in coating's hue... but the fitting to the mount is different ... and different also from an Elmar SM A36 that is a bit younger than the E39 (1.409.xxx vs. 1.355.xxx) : also, those two apparently have the top of the front lens at a slightly different distance from the flange (considering that one is SM and the other BM) . Moreover... my Elmars 90 (I have all the variants... ) , when you dismount the lenshead, show hand scratched numbers inside the lens' barrel.. which makes to think of variations of the optical Group, which need tuning/shimming of the focus mount.... In conclusion, a number of elements that make me think that it would result, if made, in a "risky transplant"... and probably costly, in comparision to lens' value : maybe it is more probable to have a well made polishing of the original lens' group. I think also that some of the best known labs (Malcom Taylor, DAG, Van Manen...) can have a definite answer about this topic. Link to post Share on other sites More sharing options...
tobey bilek Posted May 17, 2014 Share #3 Posted May 17, 2014 Lens elements do not interchange like car tires. It may work, maybe not. Link to post Share on other sites More sharing options...
Ecar Posted May 18, 2014 Share #4 Posted May 18, 2014 Chances are it won't work. Too many variables, as Luigi indicated. Polishing and re-coating is indeed a better option (I have had a rare Summar go through this kind of surgery, with great results), but the cost may not be worth it. Link to post Share on other sites More sharing options...
gyoung Posted May 18, 2014 Share #5 Posted May 18, 2014 Malcolm Taylor exchanged the rear pair of elements on my 50/3.5, but it has to be with one of the same spec, all these lenses are assembled with parts that have complementary tolerances, hence the variance in final focal length, not something for the amateur! Gerry Sent from my GT-I9505 using Tapatalk Link to post Share on other sites More sharing options...
pgk Posted May 18, 2014 Share #6 Posted May 18, 2014 Malcolm Taylor exchanged the rear pair of elements on ..... Yes, Malcolm is the man to do such things. He will then readjust the lens to optimise its performance. Not so easy and probably it would take some time as its a fair amount of work and Malcolm always has a lot to do. To be honest the collapsible 90 is probably not the most economic of lenses to do such extensive work on as they are still reasonably priced, so it may be as cheap to look for another with better optics. Link to post Share on other sites More sharing options...
carlos.paula Posted January 18, 2016 Author Share #7 Posted January 18, 2016 Advertisement (gone after registration) Well, I made the change of the front element between a collapsible 90mm Elmar and a "common" Elmar 90mm; in fact, the elements are exactly the same. The pictures results was excellent, no problem at all, and both the lens elements fits the other, correctly. Link to post Share on other sites More sharing options...
Schrödinger's cat Posted January 21, 2016 Share #8 Posted January 21, 2016 Well, I made the change of the front element between a collapsible 90mm Elmar and a "common" Elmar 90mm; in fact, the elements are exactly the same. The pictures results was excellent, no problem at all, and both the lens elements fits the other, correctly. This is an excellent piece of information. Thanx. Link to post Share on other sites More sharing options...
carlos.paula Posted January 22, 2016 Author Share #9 Posted January 22, 2016 In fact there was two series of the rigid 90 mm Elmar, an old one, with 36mm snap-on filter and a more recent, with threaded 39mm diameter, the same diameter of the collapsible version. But the front element lens is only interchangeable between these last rigid Elmar and collapsible. The older Elmar (chrome and the black ones) have the front lens diameter a half of milimeter less than the newer ones. So, the newer front elements do not fit the older Elmars. Link to post Share on other sites More sharing options...
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