Keith (M) Posted March 5, 2021 Share #61 Posted March 5, 2021 Advertisement (gone after registration) 27 minutes ago, luigi bertolotti said: Wow... little detail I never put my eye onto... my old one (920.xxx) of course has the comma... my rigid 1.7xx.xxx the dot... some of the collapsibles in the 1.3xx.xxx here depicted have the dot... now in the Forum one of our typical/funny/subtle investigations could arise... 😉 "When did Leitz changed comma to dot on the f/stops of the Summicron ?" and "when in general ?" 😎 My Collapsible 1325xxx is (AFAIK) from 1955 and has the dot. (For what it is worth!) 1 Quote Link to post Share on other sites More sharing options...
Advertisement Posted March 5, 2021 Posted March 5, 2021 Hi Keith (M), Take a look here Summicron collapsible 50mm. I'm sure you'll find what you were looking for!
Erato Posted March 6, 2021 Share #62 Posted March 6, 2021 (edited) 8 hours ago, luigi bertolotti said: Wow... little detail I never put my eye onto... my old one (920.xxx) of course has the comma... my rigid 1.7xx.xxx the dot... some of the collapsibles in the 1.3xx.xxx here depicted have the dot... now in the Forum one of our typical/funny/subtle investigations could arise... 😉 "When did Leitz changed comma to dot on the f/stops of the Summicron ?" and "when in general ?" 😎 From my humble studies, there's some information that might be useful below, just for your reference. radio-activated batch lists NR 920xxx NR 921xxx NR 922xxx NR 993xxx NR 994xxx NR 995xxx Nr 1009xxx Nr 102xxxx Nr 104xxxx If the serial number is not landing on the batches mentioned above but comes with a typical "2,8" aperture ring, and the aperture numeric/the indicator(line) does not engrave on the same level(ladder of scales hierarchically), then it may still a radio-activated lens. To figure out if its radio-activated lens or not, you may use Geiper-Müler counter in order to perform the α, β particles, and γ(Gamma) radiation measurement. Please feel free to add further supplements if you have any informative resources. Remarks: There's a good chance that your Summicron collapsible 50mm lens comes with rare earth elements even the serial number is not landing on the batches mentioned above if the color looks a bit yellow. Edited March 6, 2021 by Erato updated 1 Quote Link to post Share on other sites More sharing options...
105012 Posted March 6, 2021 Share #63 Posted March 6, 2021 My 1.28M (1955) has the dot. Quote Link to post Share on other sites More sharing options...
luigi bertolotti Posted March 6, 2021 Share #64 Posted March 6, 2021 Always intrigued by such questions... 😄 I made some quick searches (images of Cron 50 collapsible do abound) and looks that 1.04x.xxx have the comma... 1.1xx.xx have the dot.. , didn't spot items in the intermediate batch 1.091.001 - 1.097.000... (can be a long chase... 🤥) Quote Link to post Share on other sites More sharing options...
Erato Posted March 6, 2021 Share #65 Posted March 6, 2021 (edited) 31 minutes ago, luigi bertolotti said: Always intrigued by such questions... 😄 I made some quick searches (images of Cron 50 collapsible do abound) and looks that 1.04x.xxx have the comma... 1.1xx.xx have the dot.. , didn't spot items in the intermediate batch 1.091.001 - 1.097.000... (can be a long chase... 🤥) here you are... https://www.ebay.com/itm/LEITZ-Leica-Summicron-L39-50mm-F2-0-Radioactive-Lens-Yr-1953-LTM-Germany-863/324378893127?hash=item4b867d1b47:g:0BQAAOSwJxVftO~K 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! I also figure out that the engraved 'Summicron f=5cm 1:2 Nr.xxxxxxxx" has different directions against "Ernst Leitz GmbH Wetzlar. Sometimes they're on the same side, and sometimes is opposite like this one. Edited March 6, 2021 by Erato 1 Quote Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! I also figure out that the engraved 'Summicron f=5cm 1:2 Nr.xxxxxxxx" has different directions against "Ernst Leitz GmbH Wetzlar. Sometimes they're on the same side, and sometimes is opposite like this one. ' data-webShareUrl='https://www.l-camera-forum.com/topic/158389-summicron-collapsible-50mm/?do=findComment&comment=4154851'>More sharing options...
luigi bertolotti Posted March 6, 2021 Share #66 Posted March 6, 2021 (edited) Provisional conclusion looking at my lenses : the dot vs. comma looks to be a "strategic choice" 😄 around 1.100.000 , implemented not too rigorously in the workcenters 😉: - Summaron 3,5 1.004.991 : comma - Summicron 50 coll. 1.043.366 : comma - Elmar 50 RS 1.090.114 : dot (comma on the front writing 1:3,5) - close to the 1.095.xxx of the above picture... - Hektor 125 1.121.427 : dot (also on front writings 12.5 and 2.5) - Summarex 85 1.151.064 : comma (also on distances... but front writings 1.5 and 8.5 with dot...) - Summaron 3,5 1.180.456 : dot (also on distances and front writings) - Elmar 50 3,5 BM 1.184.913 : the same... and dot reigns afterwards (apart the front 1:3,5 on another Elmar RS) you need COVID restrictions to have time for these investigations.... 😒 - Edited March 6, 2021 by luigi bertolotti 3 Quote Link to post Share on other sites More sharing options...
Erato Posted March 6, 2021 Share #67 Posted March 6, 2021 Advertisement (gone after registration) 1 hour ago, luigi bertolotti said: Provisional conclusion looking at my lenses : the dot vs. comma looks to be a "strategic choice" 😄 around 1.100.000 , implemented not too rigorously in the workcenters 😉: - Summaron 3,5 1.004.991 : comma - Summicron 50 coll. 1.043.366 : comma - Elmar 50 RS 1.090.114 : dot (comma on the front writing 1:3,5) - close to the 1.095.xxx of the above picture... - Hektor 125 1.121.427 : dot (also on front writings 12.5 and 2.5) - Summarex 85 1.151.064 : comma (also on distances... but front writings 1.5 and 8.5 with dot...) - Summaron 3,5 1.180.456 : dot (also on distances and front writings) - Elmar 50 3,5 BM 1.184.913 : the same... and dot reigns afterwards (apart the front 1:3,5 on another Elmar RS) you need COVID restrictions to have time for these investigations.... 😒 - Enjoy your lenses, a pile of great lens...^^b Quote Link to post Share on other sites More sharing options...
Guest Posted March 6, 2021 Share #68 Posted March 6, 2021 (edited) vor 14 Stunden schrieb Erato: ... radio-activated batch lists ... NR 993xxx ... It also works sometimes the other way around: My collapsible screw mount Summicron No. 993xxx (only dots, no commas) seems to belong to a radioactive series, but has been proven to be non-radioactive. The following three reasons were given by Leica service department Wetzlar: 1. This Summicron was never built with radioactive lenses, or 2. This Summicron was converted into a non-radioactive lens at a later revision, or 3. This Summicron could have lost its radioactive radiance over the course of decades. Since the reasons 2 and 3 seem somewhat unlikely to me, I tend towards the first thesis as all lenses are clear and not yellowish. Leica lenses have sometimes been sorted under serial numbers that are now regarded as incorrect. Edited March 6, 2021 by mnutzer Quote Link to post Share on other sites More sharing options...
Lelmer Posted March 6, 2021 Share #69 Posted March 6, 2021 3 hours ago, luigi bertolotti said: Provisional conclusion looking at my lenses ... Nice collection 🙂 Quote Link to post Share on other sites More sharing options...
Fefes Posted March 6, 2021 Share #70 Posted March 6, 2021 (edited) 1 hour ago, mnutzer said: It also works sometimes the other way around: My collapsible screw mount Summicron No. 993xxx (only dots, no commas) seems to belong to a radioactive series, but has been proven to be non-radioactive. The following three reasons were given by Leica service department Wetzlar: 1. This Summicron was never built with radioactive lenses, or 2. This Summicron was converted into a non-radioactive lens at a later revision, or 3. This Summicron could have lost its radioactive radiance over the course of decades. Since the reasons 2 and 3 seem somewhat unlikely to me, I tend towards the first thesis as all lenses are clear and not yellowish. Leica lenses have sometimes been sorted under serial numbers that are now regarded as incorrect. With an ounce of salt, I also read that it'd depends on the purity of the source mineral of the glassworks from UK, prior to the sources and right formula settling down. The formulation with Lanthanum would be very mildly radioactive, but if it also had Thorium traces, then it would have a level that varied with Thorium oxide content. I ended up purchasing a geiger counter, and the number of lenses that didn't pass my threshold were very few, mostly Takumar lenses. None of the Leica lenses I have have any radioactivity, but never came across one radioactive Summicron to be able to measure it. I kept some lenses, such as a Killfit Killar 40mm, which is beautifully crafted, excellent properties and its radioactivity was very low and mostly alpha particles, in start contrast with the Takumars, which emitted pretty significant amounts of gamma. Gamma goes thru metal as if it was transparent, and most of the radiation is easily picked up just by touching the focus ring, but it was even concerning that most was emitted towards the camera. So my cabinets have zero of those, but I kept the ones that I consider totally harmless, such as the Killfit and a Meyer Primotar 50/2.8 that are detectable but quite low, all alpha that is stopped by not just metal, but by air itself even cm away. Now, many don't worry about any lens. It'd be nice to have some idea of the early Summicron levels, and I guess they'd be the kind of lens I'd use without any worry, unlike Pentax who had no concern whatsoever regarding this matter and continued to build red hot lenses until probably told to do otherwise. Edited March 6, 2021 by Fefes 1 Quote Link to post Share on other sites More sharing options...
luigi bertolotti Posted March 6, 2021 Share #71 Posted March 6, 2021 (edited) 2 hours ago, mnutzer said: It also works sometimes the other way around: My collapsible screw mount Summicron No. 993xxx (only dots, no commas) seems to belong to a radioactive series, but has been proven to be non-radioactive. 993.xxx with DOTS !! This kills my brilliant speculation... 😞 😁 Apart the above funny detail... Marco Cavina in the article I quoted before, quotes exactly 993.000 as the first batch which used the new LaK9 glass... non radioactive in itself.. the residual Thorium contamination in the furnaces COULD bring to a residual radioactivity but (cit) "slightly and in uneven measure" Edited March 6, 2021 by luigi bertolotti Quote Link to post Share on other sites More sharing options...
Fefes Posted March 6, 2021 Share #72 Posted March 6, 2021 6 minutes ago, luigi bertolotti said: 993.xxx with DOTS !! This kills my brilliant speculation... 😞 😁 Are the dot and coma parts interchangeable? It seems logical Leica would make large batches of the parts, then use them as needed. At some points, stock would be low, and a new batch made. This would make it so that all f2 lenses could have one or the other, and then repairs or upgrades may have resulted in upgrading the aperture ring as well. The end result being that all the information would guide as to when the batches where made, but would never amount to solving any other mystery besides...when did machining of a part batch likely started. My two Summicron collapsibles are months apart (120xxxx) and some parts in the fron part are identical, and some others are a bit different. And one is M and the another LTM. 2 Quote Link to post Share on other sites More sharing options...
Guest Posted March 7, 2021 Share #73 Posted March 7, 2021 I wonder if looking for a particular number when aperture markings were changed from "," to "." does mark anything significant. It might be that Leica decided to use a "," for lenses that were to be sold in Europe and a "." for those that were exported overseas? The European convention, evenly widely used today, is to use a "'," for the decimal point. Perhaps export 50 Summicrons all had a "." whilst European models had a "," until they decided to standardise on a "."? So perhaps early model 50 Summicrons could be either. A bit like the Leica decision to ship M3s to the US with 1/4" tripod mounts on the base plate, whereas European M3s were sold with 3/8" mounts. I have some old Hektor 135mm lenses, one has a 3/8" tripod mount (European), the aperture scale using "." (Non-European) but the 2.5 m mark on the focus ring uses a comma (2,5) European! Really mixing it up! Quote Link to post Share on other sites More sharing options...
Guest Posted March 7, 2021 Share #74 Posted March 7, 2021 vor 5 Stunden schrieb luigi bertolotti: 993.xxx with DOTS !! This kills my brilliant speculation... 😞 😁 Apart the above funny detail... Marco Cavina in the article I quoted before, quotes exactly 993.000 as the first batch which used the new LaK9 glass... non radioactive in itself.. the residual Thorium contamination in the furnaces COULD bring to a residual radioactivity but (cit) "slightly and in uneven measure" Are there any correspondences in the engraving of dots and commas between the aperture ring (2.8 and 5.6) and the ring for the distance setting (1.1 - 1.5, 1.7, 2.2, 2.5m)? My 2.0-50mm coll. No. 993xxx was only engraved with dots on both rings. Quote Link to post Share on other sites More sharing options...
didier Posted March 7, 2021 Share #75 Posted March 7, 2021 I inherited one last week-end (N° 13XX XXX). It is in a pretty good shape for its age though I think it could benefit from a CLA. Focusing could be smoother and there is quite some Dust inside the Lens. I received the M39 to M-Mount yesterday and tried it asap. Here is the very first shot ! 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! 5 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/158389-summicron-collapsible-50mm/?do=findComment&comment=4155536'>More sharing options...
Keith (M) Posted March 7, 2021 Share #76 Posted March 7, 2021 1 hour ago, didier said: I inherited one last week-end (N° 13XX XXX). It is in a pretty good shape for its age though I think it could benefit from a CLA. Focusing could be smoother and there is quite some Dust inside the Lens. I received the M39 to M-Mount yesterday and tried it asap. Congratulations - you will enjoy discovering just how good the lens is. Mine (LTM Collapsible Collapsible 1325xxx) is a pleasure to use on my M10M. 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! 10 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/158389-summicron-collapsible-50mm/?do=findComment&comment=4155578'>More sharing options...
Erato Posted March 8, 2021 Share #77 Posted March 8, 2021 (edited) Testing new arrival, vintage lens 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! P.1 -- Leitz Summicron 5cm 1:2 SOOIC, 1952 104xxxx, M10M ISO 800 f6.8 1/360s P.2 -- Leitz Summicron 5cm 1:2 SOOIC, 1952 104xxxx, M10M ISO 800 f5.6 1/250s Edited March 8, 2021 by Erato 1 Quote Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! P.1 -- Leitz Summicron 5cm 1:2 SOOIC, 1952 104xxxx, M10M ISO 800 f6.8 1/360s P.2 -- Leitz Summicron 5cm 1:2 SOOIC, 1952 104xxxx, M10M ISO 800 f5.6 1/250s ' data-webShareUrl='https://www.l-camera-forum.com/topic/158389-summicron-collapsible-50mm/?do=findComment&comment=4156241'>More sharing options...
Erato Posted March 9, 2021 Share #78 Posted March 9, 2021 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! P.3 -- Leitz Summicron 5cm 1:2 SOOIC, 1952 104xxxx, M10M ISO 800 f5.6 1/180s 6 Quote Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! P.3 -- Leitz Summicron 5cm 1:2 SOOIC, 1952 104xxxx, M10M ISO 800 f5.6 1/180s ' data-webShareUrl='https://www.l-camera-forum.com/topic/158389-summicron-collapsible-50mm/?do=findComment&comment=4156634'>More sharing options...
Fefes Posted March 12, 2021 Share #79 Posted March 12, 2021 On 3/8/2021 at 8:28 PM, Erato said: P.3 -- Leitz Summicron 5cm 1:2 SOOIC, 1952 104xxxx, M10M ISO 800 f5.6 1/180s I love the Summicron rendering. Is this a rigid version or a collapsible? 1 Quote Link to post Share on other sites More sharing options...
Erato Posted March 12, 2021 Share #80 Posted March 12, 2021 2 hours ago, Fefes said: I love the Summicron rendering. Is this a rigid version or a collapsible? I'm glad that you'd like it. It's a collapsible. Quote Link to post Share on other sites More sharing options...
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