Ruhayat Posted April 12, 2012 Share #1 Â Posted April 12, 2012 Advertisement (gone after registration) Hi. Recently, I tried to remove an old filter off my E55 Summicron 90mm but it was stuck fast and instead of unscrewing the filter, I ended up unscrewing the lens in the middle instead. Yikes! Â I could then pull the front half out of the back, and screw them back together. It seems to work fine, although I think I can see that the aperture markings are now just a tiny bit misaligned. But I'm wondering if this is normal behaviour for the lens. Are users supposed to be able to unscrew it the way I did? Â I bought the lens secondhand a couple of years ago but never actually thought it could separate like that. Link to post Share on other sites More sharing options...
Advertisement Posted April 12, 2012 Posted April 12, 2012 Hi Ruhayat, Take a look here Um, is a 90mm Summicron supposed to do this?. I'm sure you'll find what you were looking for!
k-hawinkler Posted April 12, 2012 Share #2 Â Posted April 12, 2012 How old is the lens? Â I have an older 90mm Summicron. There the lens head is supposed to come off. Then with another focus mount the lens head can be used on a Visoflex or via adapter on a Nikon for example. Link to post Share on other sites More sharing options...
Ruhayat Posted April 12, 2012 Author Share #3 Â Posted April 12, 2012 How old is it? Actually, I have no idea. It's the E55 version, made in Canada. Probably from the late 90's, if I were to guess, because the guy I bought it from said his late father acquired most of the Leica stuff during that period. Link to post Share on other sites More sharing options...
luigi bertolotti Posted April 12, 2012 Share #4 Â Posted April 12, 2012 Indeed, the E55 has not the lenshead "user unscrewable" for Visoflex usage... I think you "forced" a disassembly operation usually to be made at labs... nothing bad if, screwing the pieces together, everything is OK... but better not to repeat the operation. Link to post Share on other sites More sharing options...
peterbengtson Posted April 12, 2012 Share #5  Posted April 12, 2012 Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/177032-um-is-a-90mm-summicron-supposed-to-do-this/?do=findComment&comment=1981557'>More sharing options...
Michael Geschlecht Posted April 12, 2012 Share #6 Â Posted April 12, 2012 Hello Ruhayat, Â Since there were various 90mm Summicrons that were E55 made in Canada in the late 1990's first we have to know: Â 1. Reflex or rangefinder? Â 2. If rangefinder was it a pre Apo or an Apo? Â All of the above were made in Canada in E55 in the late 1990's. Non were of a type where the lens element was meant to be unscrewed as a unit for use on a Visoflex or on an SL or R Camera. Â BTW: A lens unit unscrewing & coming apart is not the end of the World. Â Best Regards, Â Michael Link to post Share on other sites More sharing options...
lct Posted April 12, 2012 Share #7 Â Posted April 12, 2012 Advertisement (gone after registration) ...A lens unit unscrewing & coming apart is not the end of the World... Indeed it is not. Happened to me with a Tele-Elmarit "thin" 90/2.8 and a Summicron 35/2 v4 already, none of them being supposed to have a separable lens head. Better check the focus accuracy of the lens though as some samples of the last pre-asph 90/2 happen to be somewhat touchy. Mine was accurate at infinity but not at short distance. Sent it in to Germany and now it is accurate at short distance but not at infinity any more. Makes a good portrait lens at least Link to post Share on other sites More sharing options...
Ruhayat Posted April 13, 2012 Author Share #8 Â Posted April 13, 2012 1. Reflex or rangefinder? 2. If rangefinder was it a pre Apo or an Apo? Â BTW: A lens unit unscrewing & coming apart is not the end of the World. Â Hi Michael, Â it's the M version, E55, pre APO. It's not the end of the world, no, but I had a good scare at first until I figured out you could just screw it off and then back on again, and there doesn't seem to be any effect on image quality. I'm assuming it's meant to be user-detachable since there are no screws locking anything into place and it just takes a bit of force to unscrew it. Â Actually, when it comes off it does look a bit like the diagram shown above. Except that the head unit it longer, as it goes all the way inside the bottom unit. Link to post Share on other sites More sharing options...
Ruhayat Posted April 13, 2012 Author Share #9  Posted April 13, 2012 Indeed it is not. Happened to me with a Tele-Elmarit "thin" 90/2.8 and a Summicron 35/2 v4 already, none of them being supposed to have a separable lens head. Better check the focus accuracy of the lens though as some samples of the last pre-asph 90/2 happen to be somewhat touchy. Mine was accurate at infinity but not at short distance. Sent it in to Germany and now it is accurate at short distance but not at infinity any more. Makes a good portrait lens at least  Haha. That's good to know. I tested it last night on my GF1 and it seems to be okay. I only use mine for portraits or when I want shallow DOF, with min aperture being f4, so I'm not really concerned about its infinity focus unless I want to sell it later. My theory is that since it's been in temperature controlled drybox for the past 1 year somehow it achieved optimum temperature for separation. Before that it was my only M lens for a year and I never had such problems screwing filters on and off.  Thank you for all your replies. I might send an email to Leica just to get an official word. Link to post Share on other sites More sharing options...
tobey bilek Posted April 13, 2012 Share #10  Posted April 13, 2012 E48 were the only ones designed to have optics removed.  Never tighten filters  Avoid the cheap aluminum ring ones. Buy the brass ones.Brass has a natural lubrisity with AL Al on Al is sticky by its nature. Leave it on and there might be corrosion. Link to post Share on other sites More sharing options...
lct Posted April 13, 2012 Share #11  Posted April 13, 2012 ...Actually, when it comes off it does look a bit like the diagram shown above. Except that the head unit it longer, as it goes all the way inside the bottom unit. The bottom unit must be the focussing mount i guess. Here my non separable Tele-Elmarit "thin" 90/2.8. and Summicron 35/2 v4. Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/177032-um-is-a-90mm-summicron-supposed-to-do-this/?do=findComment&comment=1981811'>More sharing options...
Ruhayat Posted April 13, 2012 Author Share #12  Posted April 13, 2012 Yes, my Summicron looks exactly like your 90mm. What worries me is that ever since I was able to separate it, it has become a lot easier to unscrew the two halves, as there is now less resistance on the join. It was tighter in the beginning.  Tobey, I was using a Hoya filter so I thought I was safe.  EDIT: actually, wouldn't it be cool if Cosina were to design a separable 90mm like this, so that you can simply twist and swap the top end for a 50mm or 75mm? Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/177032-um-is-a-90mm-summicron-supposed-to-do-this/?do=findComment&comment=1981850'>More sharing options...
Ruhayat Posted April 13, 2012 Author Share #13 Â Posted April 13, 2012 Doesn't it bother you? Have you tried sending them in for an expert opinion? Â The bottom unit must be the focussing mount i guess. Here my non separable Tele-Elmarit "thin" 90/2.8. and Summicron 35/2 v4. Link to post Share on other sites More sharing options...
lct Posted April 13, 2012 Share #14 Â Posted April 13, 2012 Doesn't it bother you? Have you tried sending them in for an expert opinion? Been using detachable lens heads like Elmarit's 90 & 135 in the past so it is pretty well a non-issue for me. Nothing but an unscrewed screw to screw again. Link to post Share on other sites More sharing options...
Ruhayat Posted April 13, 2012 Author Share #15 Â Posted April 13, 2012 Been using detachable lens heads like Elmarit's 90 & 135 in the past so it is pretty well a non-issue for me. Nothing but an unscrewed screw to screw again. Â Thanks. That made me feel a lot better. Phew. Link to post Share on other sites More sharing options...
jaapv Posted April 13, 2012 Share #16 Â Posted April 13, 2012 My SummicronC 40 comes apart quite often when I remove the lens hood. No big deal, just align the barrel and tighten. I must get that tool for giving the locking nut a final twist one day. Link to post Share on other sites More sharing options...
lars_bergquist Posted April 13, 2012 Share #17 Â Posted April 13, 2012 I am in the habit of applying a minute amount of Vaseline to the filter thread, using a toothpick. Â Also, if a filter binds, remember that lenses are basically assembled by screwing them together. So apply counterforce as high up on the lens as you can. Â The problem is that there are usually three minuscule set screws intended to keep the lens from unscrewing. Tightening those is a qualified technician's job. It takes specialised tools. I had a 28mm Summicron ASPH come apart that way. Leica say that only the Gnomes of Solms have the equipment to ensure re-assembly of ASPH lenses to the quality level required. Â The old man from the uncomplicated Kodachrome Age Link to post Share on other sites More sharing options...
bocaburger Posted April 13, 2012 Share #18 Â Posted April 13, 2012 According to what the repair gurus told me, some point in the late 70s to early 80s as a costcutting measure Leica started using cyanoacrylate (aka superglue aka crazyglue) to secure the lens assemblies rather than transverse set-screws (this continues until the present). Since they have to make the lenses disassemblable for repairs, they can't use anything that requires high heat to break the bond (like red Loctite), and so with enough age and force, the glue can come undone. Â Leica or a professional repairman will re-glue the components, and the fresh glue will not likely come apart for another couple decades. One could do it oneself, but the risk is having the glue set before you get it completely threaded down, and the threads are so precise that a solvent like acetone won't penetrate, but instead will run inside the lens and do more harm than good. Link to post Share on other sites More sharing options...
Ruhayat Posted April 13, 2012 Author Share #19  Posted April 13, 2012 I am in the habit of applying a minute amount of Vaseline to the filter thread, using a toothpick. ...The problem is that there are usually three minuscule set screws intended to keep the lens from unscrewing.  Thanks for the tip, Lars. Yes, I would have expected the two parts to be secured by a set of screws, but this doesn't appear to be the case. And now the two halves unscrew almost as if they have always been meant to do that, whereas at first it was very, very tight. I'm sure that leaves a microscopic gap big enough to permit some dust or humidity to enter, but since this seems to be a normal phenomenon and no one here is bothered by it, I suppose I will stop worrying about it as well. Link to post Share on other sites More sharing options...
Michael Geschlecht Posted April 14, 2012 Share #20 Â Posted April 14, 2012 Hello Ruhayat, Â Camera makers (Leitz/Leica included) have used universal focussing mounts for lenses of varying focal lengths for years if they are to be visually focussed, ie: Visoflex & SLR. Â When a lens contains a cam which actuates a rangefinder roller as in an M then there needs to be some sort of differential movement within the system to accomodate for variations in lens travel necessitated by differences in focal length. Â For example: The M rangefinder roller movement is designed around the 50mm lens. Lenses of shorter focal lengths do not move as far from the image plane when focussing from infinity to say 1.5 meters as a 50mm lens does. Longer lenses need to travel a greater distance from the image plane to focus @ 1.5 meters. The roller always moves the same ammount between infinity & 1.5 meters. Â It is the job of the specific differential mechanism of a given focal length to always move the roller the same ammount while @ the same time differentialy extending the lens reflective of its specific focal length. Â Best Regards, Â Michael Link to post Share on other sites More sharing options...
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