Nitrox Posted February 13, 2019 Share #1 Posted February 13, 2019 Advertisement (gone after registration) Hi! I have a Summitar 5cm with a very stiff aperture mechanism. According to this site (http://justinlow.com/articles/repair-leica-summitar) you have to unscrew the front element to get access to the mechanism. I manage to unscrew the outer ring (the line "A" marked in the attached reference picture), but to get access to the aperture mechanism, I have to unscrew the second ring (the one just above the aperture-numbers; marked "B" in the picture). However, I can't unscrew it - it's way too tight. Is this the right tool for it: https://www.ebay.de/itm/371898740111? FYI: I have the second version of the lens that is on the right. Thanks! Peter 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! Quote 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/294260-cleaning-summitar-5cm-aperture-how-to-unscrew-front-ring/?do=findComment&comment=3683483'>More sharing options...
Advertisement Posted February 13, 2019 Posted February 13, 2019 Hi Nitrox, Take a look here Cleaning Summitar 5cm aperture: How to unscrew front ring?. I'm sure you'll find what you were looking for!
frame-it Posted February 13, 2019 Share #2 Posted February 13, 2019 i used this video as reference when i cleaned my summitar Quote Link to post Share on other sites More sharing options...
Nitrox Posted February 13, 2019 Author Share #3 Posted February 13, 2019 (edited) Thanks, I know this video. But my problem is that this is obviously a different version than my Summitar. Mine has two rough rings, his has only one. I cannot unscrew the second, slimmer ring that you can see in the picture I attached. Edited February 13, 2019 by Nitrox Quote Link to post Share on other sites More sharing options...
Reini Posted February 13, 2019 Share #4 Posted February 13, 2019 I also completely disassembled and cleaned my Summitar.For that I have solved all screws. The front of the aperture ring, the 3 small screws in the tube and the 1 small screw behind the bayonet.But watch out, the screws are very delicate. For me, one screw was broken (at the bayonet), then had to get a replacement. Quote Link to post Share on other sites More sharing options...
Nitrox Posted February 13, 2019 Author Share #5 Posted February 13, 2019 Do your really have to remove any screws to unscrew the big frontring? I think this is only necessary if you want to clean the helicoid or if you want to clean the lens elements, or am I wrong? Quote Link to post Share on other sites More sharing options...
Reini Posted February 13, 2019 Share #6 Posted February 13, 2019 (edited) Sorry...I can not quite remember now. It may be that the black inlay can be solved with a rubber stopper, after the two big screws have been removed from the aperture ring. As with Minute 4.55 with the special tool. Other helpful sites https://www.photo.net/discuss/threads/help-summitar-disassembly-of-outer-most-element-and-cleaning.375949/ http://justinlow.com/articles/repair-leica-summitar https://www.rangefinderforum.com/forums/archive/index.php/t-102371.html Edited February 13, 2019 by Reini Quote Link to post Share on other sites More sharing options...
Eric Ladner Posted January 19, 2022 Share #7 Posted January 19, 2022 Advertisement (gone after registration) I have exactly the problem described by Nitrox in his first and second posts. Was there ever a solution? I don't see it in the thread so far, and I don't want to apply more than hand-strength force to the second lens group unless I'm sure it can be unscrewed. Interestingly, with the first lens element and the two screws removed, the aperture number ring moves freely, and once I was even able to open and close the diaphragm blades, leading me to believe they are not frozen either. (Unfortunately, I can't remember how I did it, and haven' t been able to do it again--a hazard of working late at night.) But when it's reassembled everything is frozen in place again. At least I was able to get it set to f2, which I guess is not so bad for a lens noted for its unusual bokeh! Is it time to pack it up and send it to a professional? Quote Link to post Share on other sites More sharing options...
250swb Posted January 20, 2022 Share #8 Posted January 20, 2022 (edited) Just watch the video, it explains very clearly how to do it and in reality it's a five minute job if you have everything at hand. I think if you've taken the screws out already you've got to take it apart now anyway. But cleaning a sticky aperture ring on a Summitar is just about the easiest bit of DIY you can do on any Leica lens. Apart from the screwdriver you need some IPA to clean the old sticky grease off (it will probably look like varnish), and the tiniest smear of helicoid grease for re-assembly. Edited January 20, 2022 by 250swb Quote Link to post Share on other sites More sharing options...
jerzy Posted January 20, 2022 Share #9 Posted January 20, 2022 Eric, notice the slot on upper photo, this is where the screw from aperture ring comes into and this is how you may move the aperture without the ring. Photo shows fully opened position, slot is on the right. Watch out when you remove the front group and without the apertuire ring and screws - do not place the lens upside down. The black, inner ring seen on the lower photo may fall out, blades may fall out. Assembling aperture is possible without special tools but it is nasty job, may take a lot of your time. 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! 1 Quote 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/294260-cleaning-summitar-5cm-aperture-how-to-unscrew-front-ring/?do=findComment&comment=4362256'>More sharing options...
jerzy Posted January 20, 2022 Share #10 Posted January 20, 2022 just now I read through the old postings as well....To complete the story about cleaning Summitar: there are 2 variants of LTM Summitar. The older ones have one grove on the tube, tube constists of 2 parts and can be separated and the aperture opening is circular. The later version has 2 groves, tube consists of just one part and it has hex aperture (it is possible that hex aperure may be found as well in earlier version with one groove but I have not seen such lkebns yet). Change was approx between 550xxx and 580xxx. In both versions the construction of the front group is the same, as well unscrewing works in the same way. You might need rubber gloves to unscrew. Attention: extract and arrest the lens before unscrewing the front group. Othewise it is very probably that you will damage the grove(s). If you need to clean the lenses adjacent to aperture blades (this is usually where they become hazy): - in older version remove 3 tiny screws on the tube, pull upper part out 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! - in the newer version : (I do not have appropriate photos now) push the lens tube inside the mount, remove the screw (see below), unscrew the black ring. Then, having spanner wrench you may unscrew and remove the rear group for cleaning 3 Quote Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! - in the newer version : (I do not have appropriate photos now) push the lens tube inside the mount, remove the screw (see below), unscrew the black ring. Then, having spanner wrench you may unscrew and remove the rear group for cleaning ' data-webShareUrl='https://www.l-camera-forum.com/topic/294260-cleaning-summitar-5cm-aperture-how-to-unscrew-front-ring/?do=findComment&comment=4362327'>More sharing options...
mixtape Posted February 14, 2023 Share #11 Posted February 14, 2023 hello @jerzy, maybe you can help me. I have a summitar 50 f/2.0 from the late 1940s, its the 10 blade version. It arrived today, the aperture ring was stuck. I managed to unscrew the front lens group, cleaned the aperture ring, the cage and also the blades and were able to do the 'nasty job' and getting back in all the blades. The aperture ring and everything works pretty fine now, but the mark on the front tube, does not fit the aperture range. Instead of going from f2 to f16 it starts at around f1.8 and stops at 11. Do you have any idea how I can fix that? The front lens is tight, not to tight, I would need to losen it, whats bullshit. Could it be the base of the blades? The part with the holes where the blades are locked in the tube that neets to be rotated or so? This part in your picture: 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! Thank you! M Quote Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! Thank you! M ' data-webShareUrl='https://www.l-camera-forum.com/topic/294260-cleaning-summitar-5cm-aperture-how-to-unscrew-front-ring/?do=findComment&comment=4685785'>More sharing options...
jerzy Posted February 14, 2023 Share #12 Posted February 14, 2023 (edited) no, you cannot rotate the base it is part of the tube, manufactured of one piece of brass. You would rather need to manufacter a very thin shim and place it under the front group. Or, even better, take the blue Loctite (screw fixing fluid), put one small drop on the thread and screw in the head to match the dot. Few hours later head will be fixed, but not that hard that you would not unscrew it using proper tools Edited February 14, 2023 by jerzy Quote Link to post Share on other sites More sharing options...
mixtape Posted February 15, 2023 Share #13 Posted February 15, 2023 ok, I also thought about a shim, but the idea with loctite is pretty good. BUT! let me ask: wont this affect sharpness anyway and how could this issue occure as theres no shim in this version of the lens? Quote Link to post Share on other sites More sharing options...
jerzy Posted February 15, 2023 Share #14 Posted February 15, 2023 it should have no impact on sharpness. Firstly, approx 2mm distance between 11 and 16 translates into few microns of the position of front group and secondly you cannot assembly it in a wrong way.Base of blades is part of the tube, similarly cutouts for blades travel are cut fix in the tube. I believe that during production drilling the dot was one of the last steps after lens has been assembled and it was drilled to match the index on the aperture ring. I do not know why in your lens the groups screws in too far, ususallly I have opposite case if not cleaned the thread carefull enough 1 Quote Link to post Share on other sites More sharing options...
mixtape Posted February 15, 2023 Share #15 Posted February 15, 2023 Thank you! My mechanical skills are better than my optical math skills I am not sure if the lense has been shipped this way. Maybe one of the pre owners already engaged on the lens. Maybe he exchanged some parts, or changed the front lense group or so. The blades were oiled, and the tube was overrotaded so the collapsing function did no longer work. I think some "expert" did a bad job. I will try the loctite solution, as its a harmless way, and I have no way to machine a shim. I also read a few repair manuals in which exactly your case was told, like the mark is the other way and some of those guys used force... Thank you so far for your very fast support! Quote Link to post Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.