cwolffensperger Posted January 6, 2015 Author Share #21 Posted January 6, 2015 Advertisement (gone after registration) And thanks everyone for thinking with me! Quote Link to post Share on other sites More sharing options...
Advertisement Posted January 6, 2015 Posted January 6, 2015 Hi cwolffensperger, Take a look here Leica IIIa & summaron 2.8. I'm sure you'll find what you were looking for!
zeitz Posted January 6, 2015 Share #22 Posted January 6, 2015 Now I'm really curious. The clear evidence is that the focus mount pitches and the infinity distances are different. But there is no explanation of the physics. Why is there a wedge in the viewfinder goggles for the f2.8 Summaron when it was not there for the f3.5 Summaron? Is the wedge also there for the f3.5 and the capability to remove the goggles is there only for storage convenience and not for use on non-M3 cameras? How do the two lenses (the glass, not the mount or focusing ramp) that are supposed to use the same optics achieve the same distance to the film plane at each subject difference? The measurements do not address the position of glass in the lens. Quote Link to post Share on other sites More sharing options...
luigi bertolotti Posted January 6, 2015 Share #23 Posted January 6, 2015 (edited) Now I'm really curious. ... Why is there a wedge in the viewfinder goggles for the f2.8 Summaron when it was not there for the f3.5 Summaron? I think that the reason is that the Summaron 35 3,5 focuses down to 1 meter also in the goggled version... when Leitz designed the Summaron 2,8, probably they considered a plus the capability to focus down to 0,65m ...and they achieved this altering the standard geometry of the rangefinder with the famed wedge (the std M rangefinder has 0,7m as its normal limit) ; note that this is the shortest distance achieved with a standard RF coupled lens (apart the DR Summicron, which uses a different system) ; other lenses have shorter minimum focus (the SA 21s), but not coupled to RF mechanism ; I don't know if the prototype Elmarit 21 with goggles (which focused to 40cm, differently from the definitive lens, which has the usual 70cm) had an optical trick similar to the one they made for the Summaron 2,8. Edited January 6, 2015 by luigi bertolotti Quote Link to post Share on other sites More sharing options...
luigi bertolotti Posted January 6, 2015 Share #24 Posted January 6, 2015 (edited) So - just for the clarity, because I'm a bit confused - using the goggles with my 'LTM' 0,65m summicron on a M3 should focus properly? Yes... provided you find them as ORIGINAL for Summaron 2,8... which imho isn't an easy find (not to speak of MOUNTING them... the mount is completely different... not a simple "attachment"). BTW, Summicron 35 and Summilux 35 with goggles have the same minimum focus of 0,65 m, so the goggles are, I think, optically identical. Edited January 6, 2015 by luigi bertolotti Quote Link to post Share on other sites More sharing options...
cwolffensperger Posted January 6, 2015 Author Share #25 Posted January 6, 2015 Hmm, sounds like it's difficult to attach them. Just putting them before the VF and RF isn't possible? Quote Link to post Share on other sites More sharing options...
luigi bertolotti Posted January 7, 2015 Share #26 Posted January 7, 2015 Hmm, sounds like it's difficult to attach them. Just putting them before the VF and RF isn't possible? I doubt one can find a decent do-it-yourself solution to fit the goggles in front of the RF/VF... maybe one could try to join/solder a LTM/M adapter to a goggle unit... ... Quote Link to post Share on other sites More sharing options...
joeswe Posted January 7, 2015 Share #27 Posted January 7, 2015 Advertisement (gone after registration) AFAIK the goggled version of the 3.5 Summaron is no different from the 2.8 in this respect. It will not focus correctly without the goggles, or to be more precise, it will not focus at all, as the lens is then locked at infinity. As Luigi has already indicated, retrofitting a 2.8 Summaron with goggles is not worth the effort, as the goggles alone are difficult to find (while the complete lens itself is plentiful and cheap) and in your case you would not only need to find the goggles, but also the base to which they attach, which seems to be part of the M mount that fits on the screwmount threads. Best to return the lens to the seller, if possible. Quote Link to post Share on other sites More sharing options...
luigi bertolotti Posted January 7, 2015 Share #28 Posted January 7, 2015 AFAIK the goggled version of the 3.5 Summaron is no different from the 2.8 in this respect. It will not focus correctly without the goggles, or to be more precise, it will not focus at all, as the lens is then locked at infinity.... . Hum... are you sure of ? I wouldn't swear on... (tonight will inspect with care my goggled 3,5...) I have the feel that if one removes the collar to which the goggle unit is fit, probably is true that the lens cannot anymore be focused... but I have also the feel that the goggles are optically different from the 2,8 (and Summicron/Summilux) in the sense that they do not introduce modification in the optical path of the RF... they are simply a pair of negative lenses that reduce the image size in the window(s) ... the inverse of what is made by the goggles of the TE 135 2,8... Quote Link to post Share on other sites More sharing options...
cwolffensperger Posted January 8, 2015 Author Share #29 Posted January 8, 2015 Okay, I pulled the trigger and bought the goggles (they were quite cheap compared to what I've found on ebay). Put a ltm-m adapter for 50mm frame lines on the summaron, and (hope I won't offend anyone here) glued the goggles on the lens. And actually: it seems all okay. Focussing gives the same results as with another lens, and removing the lens etc is still possible. So hopefully it stays together now ;-). Thanks for all the tips guys! Quote Link to post Share on other sites More sharing options...
joeswe Posted January 8, 2015 Share #30 Posted January 8, 2015 Hum... are you sure of ? I wouldn't swear on... (tonight will inspect with care my goggled 3,5...) I have the feel that if one removes the collar to which the goggle unit is fit, probably is true that the lens cannot anymore be focused... but I have also the feel that the goggles are optically different from the 2,8 (and Summicron/Summilux) in the sense that they do not introduce modification in the optical path of the RF... they are simply a pair of negative lenses that reduce the image size in the window(s) ... the inverse of what is made by the goggles of the TE 135 2,8... No, I must admit I am not sure about this point. I have never owned any version of the 3.5 Summaron, so my comment is just based on what I heard or picked up on the web. Please do inspect your copy and report back here, I am curious to know. Quote Link to post Share on other sites More sharing options...
luigi bertolotti Posted January 12, 2015 Share #31 Posted January 12, 2015 Okay, I pulled the trigger and bought the goggles (they were quite cheap compared to what I've found on ebay). Put a ltm-m adapter for 50mm frame lines on the summaron, and (hope I won't offend anyone here) glued the goggles on the lens. And actually: it seems all okay. Focussing gives the same results as with another lens, and removing the lens etc is still possible. So hopefully it stays together now ;-). Thanks for all the tips guys! Well... a lucky end... : can you post a picture of your "re-goggled" item ? I'm curios to see the result... Quote Link to post Share on other sites More sharing options...
jc_braconi Posted January 12, 2015 Share #32 Posted January 12, 2015 Very intriguing discussion here I am wondering if people have made some (mechanical) reflexion before posting .... Quote Link to post Share on other sites More sharing options...
cwolffensperger Posted January 12, 2015 Author Share #33 Posted January 12, 2015 Well I can show you the result over here. What I've done is I've put a LTM-M mount adapter (50-75 to show the 50mm frame lines on my M3) on it. And then assessed the position where to goggles should go with the lens attached to the body. Now that I've asserted myself that this was the right position (rangefinder vertically and horizontally aligned), I simply glued the goggles on. And this is what it looks like [emoji6] With the adapter dismounted Just a little of the goggles not touching, so I guess the original mount was a little larger And quite 'tight' in front of the viewfinder 1 Quote Link to post Share on other sites More sharing options...
luigi bertolotti Posted January 12, 2015 Share #34 Posted January 12, 2015 No, I must admit I am not sure about this point. I have never owned any version of the 3.5 Summaron, so my comment is just based on what I heard or picked up on the web. Please do inspect your copy and report back here, I am curious to know. Hup... I made a grossly wrong statement when I wrote that the goggled Summaron 3,5 focuses down to 1 m... was sufficient to look at my one to verify that its minimum focus distance is indeed 0,65 m (2'2")... sorry, clearly the goggle unit is optically identical in all the 35s... 1 Quote Link to post Share on other sites More sharing options...
jaapv Posted January 13, 2015 Share #35 Posted January 13, 2015 Also the goggles can only affect the viewfinder, not the rangefinder. The 3.5 Summaron exemplifies this as its goggles are removable for use on M3 or any other M that is not an M3. The goggles have a lens in front of the viewfinder window and in front of the rangefinder window; that is why they affect both. The removable goggles on the Summaron are meant for easy transport, emphatically not for use of the lens without them. That is why the lens locks at infinity with the goggles removed: it is the only correct distance setting. Quote Link to post Share on other sites More sharing options...
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