Guest Posted July 9, 2018 Share #1  Posted July 9, 2018 (edited) Advertisement (gone after registration) I just noticed that my 75mm Summilux has a small number "50" engraved next to the m on the distance scale. By my understanding this means the actual focal length of this lens is 75mm + 5.0mm = 80mm.  So looked around on Ebay, there a large number for sale, and came to this conclusion:-  All version 1 lenses have a "00" engraved, making them true 75mm All version 2 and 3 have a "50" engraved, making them all 80mm lenses (like the 80mm R from which they are descended).  Is my understanding of this engraving correct and does any one out there have a version 1 with something other than "00" or a version 2/3 with something other than "50" engraved? Edited July 9, 2018 by Guest Quote Link to post Share on other sites More sharing options...
Advertisement Posted July 9, 2018 Posted July 9, 2018 Hi Guest, Take a look here Summilux 80mm F1.4?. I'm sure you'll find what you were looking for!
andybarton Posted July 9, 2018 Share #2  Posted July 9, 2018 The 50 engraving means that it's 75.5mm, not 80mm.  The 50 = 50/100th mm  There is a long thread about this here:  https://www.l-camera-forum.com/topic/249125-small-19-beside-m-on-distance-scale-black-rigid-summicron/ Quote Link to post Share on other sites More sharing options...
a.noctilux Posted July 9, 2018 Share #3  Posted July 9, 2018 (edited)  Is my understanding of this engraving correct and does any one out there have a version 1 with something other than "00" or a version 2/3 with something other than "50" engraved?   Wrong!  The two digits = 0.1mm last number real measured focal length. So your 75mm lens with "50" = 75.0mm  The other with "00" would not occure in 75mm lens (that would be measured 70.0 mm or 80.0mm), only possible with Summilux-R 80mm.  Just had a look at my Summilux-R 80mm, that has "00" marking on the focus ring. While my Summilux-M 75mm has "50" like yours.  ... Side note, my Noctilux-M 50mm 1.0 is like other same Noctilux lens always "00" marking = measured 50.0mm focal length. Edited July 9, 2018 by a.noctilux Quote Link to post Share on other sites More sharing options...
Guest Posted July 9, 2018 Share #4  Posted July 9, 2018 (edited) Wrong!  The two digits = 0.1mm last number real measured focal length. So your 75mm lens with "50" = 75.0mm  The other with "00" would not occure in 75mm lens (that would be measured 70.0 mm or 80.0mm), only possible with Summilux-R 80mm.  Just had a look at my Summilux-R 80mm, that has "00" marking on the focus ring. While my Summilux-M 75mm has "50" like yours.  ... Side note, my Noctilux-M 50mm 1.0 is like other same Noctilux lens always "00" marking = measured 50.0mm focal length. Thanks for both replies. If you check out the version 1 75mms on Ebay , 3 or 4 of them listed, they all have "00" engraved, if "50" means is is actually a 75mm lens then what does the "00" signify? Are they then 70mm? Edited July 9, 2018 by Guest Quote Link to post Share on other sites More sharing options...
Guest Posted July 9, 2018 Share #5  Posted July 9, 2018 (edited) Thanks for both replies. If you check out the version 1 75mms on Ebay , 3 or 4 of them listed, they all have "00" engraved, if "50" means it is actually a 75mm lens then what does the "00" signify? Are they then 70mm? 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! Edited July 9, 2018 by Guest 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/286438-summilux-80mm-f14/?do=findComment&comment=3552497'>More sharing options...
01af Posted July 9, 2018 Share #6 Â Posted July 9, 2018 (edited) By my understanding this means the actual focal length of this lens is 75 mm + 5.0 mm = 80 mm. Your understanding is wrong. The small number "50" is in tenths of a millimeter, so this much is correct. But it must not be added to the nominal focal length. Instead, it denotes the last two digits of the actual focal length, i. e. one digit before and one behind the decimal point. Â So the "50" on a 75 mm lens denotes an actual focal length of 75.0 mm. A number "98" on a 90 mm lens, for example, would mean, 89.8 mm. Â The Canadian-made Summilux-M 75 mm lenses are an exception to this rule, as the Canadians obviously didn't understand how this was supposed to work. They wrongly marked their lenses "00" which is this case is meant to be the difference between nominal and actual focal length. So again, the actual focal length is 75.0 mm. Edited July 9, 2018 by 01af Quote Link to post Share on other sites More sharing options...
Guest Posted July 9, 2018 Share #7  Posted July 9, 2018 (edited) Advertisement (gone after registration) Your understanding is wrong. The small number "50" is in tenths of a millimeter, so this much is correct. But it must not be added to the nominal focal length. Instead, it denotes the last two digits of the actual focal length, i. e. one digit before and one behind the decimal point.  So the "50" on a 75 mm lens denotes an actual focal length of 75.0 mm. A number "98" on a 90 mm lens, for example, would mean, 89.8 mm.  The Canadian-made Summilux-M 75 mm lenses are an exception to this rule, as the Canadians obviously didn't understand how this was supposed to work. They wrongly marked their lenses "00" which is this case is meant to be the difference between nominal and actual focal length. So again, the actual focal length is 75.0 mm. Now very confused, Version 1 "00" marking and version 2 "50" marking were both made in Canada, Version 3 "50' marking was made in Germany? The other reply said the this number is 1/100mm, who's correct?  I still go by 50 means plus 5mm, like 19 on my 50mm summicron means 1.9mm, i.e 51.9mm  But I actually get what you means, thanks for clarifying, the number replaces the last digit of the focal length in 10ths of a mm , so "00" and "50" mean exactly the same on the 75mm, trivia question, "when does 0 equal 50" answer: When Leica decide. Edited July 9, 2018 by Guest Quote Link to post Share on other sites More sharing options...
01af Posted July 9, 2018 Share #8 Â Posted July 9, 2018 (edited) ... and version 2 "50" marking were both made in Canada ... Okay, so after a few years someone explained to them how these little numbers are to be used properly. Â Â The other reply said the this number is 1/100 mm ... That's just wrong; ignore it. Â By the way, I just noticed the little number on my late (German-made) copy of the Summilux-M 75 mm is "53". So my lens' actual focal length is 75.3 mm. Edited July 9, 2018 by 01af Quote Link to post Share on other sites More sharing options...
andybarton Posted July 9, 2018 Share #9 Â Posted July 9, 2018 That's that cleared up then... Â Why not just engrave "51.9" or "75.5" on a lens so that it is clear to everyone? 1 Quote Link to post Share on other sites More sharing options...
Exodies Posted July 9, 2018 Share #10 Â Posted July 9, 2018 To stop people from rummaging through the stock. Quote Link to post Share on other sites More sharing options...
andybarton Posted July 9, 2018 Share #11 Â Posted July 9, 2018 Stock?! Quote Link to post Share on other sites More sharing options...
luigi bertolotti Posted July 9, 2018 Share #12  Posted July 9, 2018 (edited) That's that cleared up then...  Why not just engrave "51.9" or "75.5" on a lens so that it is clear to everyone? ..too long for spaces that, depending on lenses, can be very narrow…   My Apo Telyt 135 has "57" --> 135,7 which are 3 more characters (+150 % !!!)  with a comma/point to be engraved VERY little… My Macro Elmar 90 has "06"--> 90,6 and the Elmarit M 90 "15"--> 91,5...  The question of the Summilux 75 1st is a bit intriguing… apart the "00" quoted by the OP I have direct evidence of a Summilux 75mm 1st with "05" … maybe there is some truth in the urban Leitz legend that the first batch of Summilux 75 were indeed 80 like their contemporary R brothers ? Edited July 9, 2018 by luigi bertolotti Quote Link to post Share on other sites More sharing options...
01af Posted July 9, 2018 Share #13 Â Posted July 9, 2018 ... maybe there is some truth in the urban Leitz legend that the first batch of Summilux-M 75 mm were indeed 80 mm like their contemporary R brothers? Don't think so ... but it's easy enough to check out. Just take two pictures of a distant scene, one with your Summilux-M 75 mm and one with a lens of well-known focal length, such as 51.9 mm or 91.5 mm. Then compare and compute the 75 mm's actual focal length, for example by using the Ruler tool in Photoshop to measure the relative sizes of one feature in the pictures. Quote Link to post Share on other sites More sharing options...
luigi bertolotti Posted July 9, 2018 Share #14  Posted July 9, 2018 Don't think so ... but it's easy enough to check out. Just take two pictures of a distant scene, one with your Summilux-M 75 mm and one with a lens of well-known focal length, such as 51.9 mm or 91.5 mm. Then compare and compute the 75 mm's actual focal length, for example by using the Ruler tool in Photoshop to measure the relative sizes of one feature in the pictures. If only had one…  .. but Others can do by sure… I'm curios about…  My only 75 is Summarit (no engraving on exact focal) … compared with Summicron 51,9 and resulted to be a bit under 75 (something like 74,88.. can't swear on the 2nd decimal) Quote Link to post Share on other sites More sharing options...
Exodies Posted July 9, 2018 Share #15 Â Posted July 9, 2018 Stock?! The lenses in the camera shop - the stock. Quote Link to post Share on other sites More sharing options...
lct Posted July 10, 2018 Share #16 Â Posted July 10, 2018 Indeed "50" means 75mm here but i would not put too much trust on those markings. Both my 75/1.4 and 75/2 have a "50" engraving but the 75/1.4 is significantly wider. Quote Link to post Share on other sites More sharing options...
luigi bertolotti Posted July 10, 2018 Share #17  Posted July 10, 2018 (edited) Indeed "50" means 75mm here but i would not put too much trust on those markings. Both my 75/1.4 and 75/2 have a "50" engraving but the 75/1.4 is significantly wider. Gosh… Leica is no more like it used to be…  … why discuss on such minutiae about those small numbers if they aren't trustworthy ? Edited July 10, 2018 by luigi bertolotti Quote Link to post Share on other sites More sharing options...
01af Posted July 10, 2018 Share #18 Â Posted July 10, 2018 Both my 75/1.4 and 75/2 have a "50" engraving but the 75/1.4 is significantly wider. At which focusing distance? Quote Link to post Share on other sites More sharing options...
lct Posted July 10, 2018 Share #19 Â Posted July 10, 2018 At which focusing distance? Â On closeups mainly. Quote Link to post Share on other sites More sharing options...
01af Posted July 10, 2018 Share #20 Â Posted July 10, 2018 On close-ups mainly. Compare at infinity focus. There, the two 75 mm lenses' fields-of-view should be equal when both are marked "50". At close range, the fields-of-view will be different because the Apo-Summicron-M 75 mm Asph has floating elements and the Summilux-M 75 mm has not. That will affect the effective fields of view in different ways. 1 Quote Link to post Share on other sites More sharing options...
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