-The second edition is 1956- 1968, which is rigid in silver (Chrom), and there are also a few specially customized black paint editions and precious M39 screw tooth edition (screw seat, 1 160). From the aesthetic point of view, this lens looks very beautiful, focusing on the lever, and feels very good, so both users and players are pursuing it. A Japanese photography magazine (note) once tested this lens and thought it had the highest definition among all Summicron 50mm (taking into account the low contrast). Note: The 50/2 Summicron mentioned in this paragraph is probably Lycra communication. It was once thought to have the same optical design as Summicron's first edition, but it turns out that there are some differences between the two lenses. Although the structures of the two lenses are similar, the second edition and the third edition both use four LaK9 rare earth glasses developed by Leica. The distance between the first lens and the second lens is increased from 0.28mm to 1.52mm, which solves the problems of aberration and dispersion, improves the resolution and makes it fully open. The lens group has 6 groups of 7 lenses. The coating of the front lens LaK9 is very soft and easy to scratch or wipe. The nearest focal length is 1 m. The production year also includes 50mm DR, so some documents put 50mm rigid and 50mm DR in the same version. According to Erwin Putt's data, the mirror group design of the two is considered to be exactly the same. Some data also show that 50mm DR has adjusted the second, fifth and sixth lenses for the smoothness of the image field, but the information and time of the modification are not clear. (Note 2) Note 1: Comparative Doctor and' Rare Earth' Summit Note 2: Great brand! In the M 50MM rigid article, there are photos of the front and rear lens groups that are rigidly unscrewed. It seems to be slightly different from DR (one lens barrel of the aperture blade has also been removed), but the structural difference can't be confirmed, and it may just be the focus adjustment for the close-up range. Reference pictures: The carvings of Rigid 1, Rigid 2 and DrRigid65438 are slightly modified, but there is no clear division. The early sculpture of the mirror mouth is Ernst Leitz GmbH Wetzlar, F = f=5cm 1:2 Nr. XXXXXX, and the focus ring of the mirror body is only marked with the German word feet or meters (m); LEITZ WETZLAR was engraved on the mirror mouth in the later period, and there was no Nr. Before the serial number, there is 1: 2/50. The focus ring of the mirror body is marked with feet and meters (m) at the same time, with the words Germany or German-made lens. At the same time, the focal length number 19( 19 means that the focal length of the ex-factory test lens is 5 1.9mm, 16 means that the focal length of the ex-factory test lens is 5 1.6mm, and so on if there are the same marks) was written in the early stage (note). (But it will still be engraved on the inner lens barrel as the factory test certificate. )
-The third edition, 1956- 1968, is a DR(Dual Range) version, with two focusing ranges in silver and several special black paint versions of prototype. Although most "experts" say that its optical design is the same as rigid, according to the tests of American photography magazines and modern photography magazines that have stopped publishing in the United States, this 50mm DR has the highest definition among all the tested lenses, exceeding 100 LP/mm, and its image resolution is far superior to that of negative films. Like rigidity, the lens group consists of 6 groups of 7 lenses. Among all M lenses, its near-focus ability is the strongest. At the same time, many experienced DR players claim that the performance of the two lenses is different, which is believed to be caused by their different optical designs. Because of the addition of a platform for goggles (SDPOO), DR is not so rigid and attractive. Nevertheless, this lens combines high resolution and low contrast, and has extremely beautiful out-of-focus imaging (shot), which is still favored by users. Note: the text source of Leica M 50/2 dual-range Summicron 50 mm DR has been slightly modified. The early version of DR recently focused on 19 inch (48.26 cm), and the mirror mouth was engraved with Ernst Leitz GmbH Wetzlar, F = f=5cm 1:2 Nr. XXXXXX and the focusing ring are slightly narrower, with only feet or meters (m) scales on them (they do not exist at the same time), and the knurling of the focusing ring is slightly shallow. In addition, the magnification is marked from 1: 15 to 1:0.75, and there is a trademark with a border on the early glasses, which reads "E. Leitz/Wetzlar". Later versions of DR were recently focused to 20 inches (50.8 cm) and engraved with LEITZ WETZLAR, no Nr. Before the serial number, there is 1: 2/50. The focus ring is slightly wider, with feet and meters (m) engraved on it, and the magnification is not marked. Its glasses are engraved with the words "Leitz Wetzlar" without borders, and the knurling between the ridges is bigger and deeper. The expensive classic chrome-plated front cover is easy to fall off, dent or scratch (mine is), so it's also a good idea to put it away, find a plastic cover to replace it, or use an inverted hood. (Note) Note: The range hood models available for 50mm DR are both practical and classical, and can be used for reference: 12538 (plastic, reversible), 12585/ 12585H (metal, reversible, 12588). 50 mm 12549 (chrome)/12550 (black) spiral tooth (39 mm) cover for elmar-m is also acceptable, but protective glasses or filters cannot be used. The other said that the coating on DR lenses was warmer and harder, and the contrast and optical performance were better (note 1), but there was no record of changing optical materials. It is not sure whether all DR lenses were so different in the later period. You may need to pay special attention when buying, because the fixed steel balls on the glasses platform in the early stage are relatively large, so the close-up glasses in the early stage can be used for the DR lenses in the later stage, and the close-up glasses in the later stage cannot be used for the DR lenses in the early stage. It is recommended to find a combination to sell with glasses, because there is a difference between the early and late stages of DR, and it is also a problem to buy and match separately. Glasses with a small leather case are not easy to find, but I personally think it is dispensable. In addition, the coating of the front lens is very soft, easy to scratch or fog, and it is also very likely that the internal coating will deteriorate. If it needs cleaning, it may be worth measuring. The Leica Visoflex system (Note 2) can also be used with the special connecting ring after removing the DR lens group and lens barrel. Generally, the serial numbers of the front and rear lens barrels will be checked when purchasing. (Please refer to the film) Note 1: The fourth paragraph of the building speech Note 2: Can Su Micron 50F2 rigid lens be decomposed? There is a simple explanation in the article.
DR can only be mounted on the fuselage without glasses. That pair of glasses is an accessory that can be loaded and unloaded at any time (the timing of lens loading and unloading will be detailed later), and it can be conveniently placed on the platform in front of the RF viewfinder of the fuselage. Leica explained that this kind of mirror can't be used on M8 and M9, probably because the cabin size of M8 and M9 is different from that of negative film machine. The rear edge of the lens barrel (the part that drives the linkage ranging mechanism) within the range of DR close-range focal length is too prominent, and it will be pushed to the internal mechanism at the general focal length (4m ~∞), so it can't be used (or installed), so the close-range focal length can only be used. Coupled with the M-machine with slightly higher fuselage, such as M6 TTL and M7, it is uncertain whether the close-range glasses can completely cover the RF viewfinder. Epson R-D 1, Leica CL and Minolta CLE can also be fitted with DR, but the width of close-range glasses will be different from that of RF viewfinder (M5 is also possible), and Zeiss Ikon ZM and Bessa series can also be fitted. Similarly, glasses will have matching problems and cannot be rotated to infinity (only to the middle of 10m ~∞) (Luo Lai 35RF is. In addition, some experts have tried it, and Konica Hexar RF can completely use 50mm DR, which should be the only body that can completely use DR without Leica RF. Note: there is a compatibility list in this section, and it is also said that 1m ~∞ cannot be used. In short, there will be some problems with the general focal length. There are several ways to use DR on M8 and M9. The first way is to directly smooth the protruding part of the rear edge of the lens barrel, but this will also make DR lose its close-up function, so it is better to directly find another 50mm one to use. The second way is more complicated, that is, unscrew the rigid /DR lenses of the same period respectively, assemble the front lens of DR to the rigid rear lens barrel, and then mount M8 and M9, so that it can work with the general focal length of DR (1m ~∞); Then, when M8 and M9 use the close-range focal length, directly use the original lens barrel of DR, and then remove the plastic (pull ring) on the glasses for auxiliary fixation (attention). These players' experiments suggest that the rigid structure is very similar to DR, and the optical quality and rigidity of DR are really different and have their own uniqueness. Note: Leica M8 &；; 50 mm f2summitron Dr, Leitz Summicron 50/2 DR used in M8/M9 method, 1963 summitron 50/2 DR will not be mounted on M8, and it is said that it can be played like this. Besides, it is absolutely risky. It's useless if the screw tooth breaks or "moves the clock" to move the focus of the lens. If you really want to play like this, you must think clearly. In addition, it may be necessary to pay attention to the hand-carved marks inside the front and rear lens groups after they are unscrewed, which is the actual focal length tested at the factory. It is best to choose the same one, such as 5 1.9, to avoid more problems. There is also a 5 1.9, but the focus gauge can't match after combination. The last one is to find an old connecting ring UOORF SOMKY to switch, so that the DR lens group can be used normally in general focal length and near focal length, but it seems that it can not completely cover the original near focal length of DR, and it is not very convenient to use. Experienced users on the Internet also suggest that when the 50mm DR is installed on the fuselage, it is best to turn it to an infinite position, otherwise it may be difficult for the lens to get on and off the fuselage. The reason is that the back end of DR drives the focusing lens barrel in the close range, which is quite different from the focusing lens barrel in the normal range and almost at right angles. If the camera does not rotate infinitely before going up and down, the difference may be stuck without bypassing the RF focusing mechanism. When I get the lens up and down by myself, I sometimes encounter such a situation, that is, the part of the focus table near the distance section (between 1m and 1.2m) will get a little stuck when I want to take it off. The field of view should be caused by the right-angle occlusion of the close-up part, so I can get up and down the camera normally when I turn to 1.5m, but it is easier to remember the operation procedure, so I'd better turn to infinity directly.
In the user manual, it is suggested that when using the close-up function, the lens should be installed behind the camera, the focus ring should be lifted up, and the tenon should move around the separated small baffles to reach the close-up focal length (the farthest distance between close-ups is about 88 cm). At this time, the focus ring will be in a fixed state (please don't turn it forcibly), so you can install glasses and use the close-up function correctly. The reason why the focus ring can only be rotated for close-up is because the steel ball on the platform where the glasses are installed is used to ensure that the glasses are equipped with a mechanism to prevent radio frequency damage caused by arbitrary rotation. Some people will hold down the steel ball for close-up focusing, but this is not recommended. After wearing glasses, the tenon will not turn back to the normal focal plane, so please be careful not to turn the lens on your hand hard. Although it is a brass alloy lens barrel, it feels stronger than modern mirrors. To take off the lens, you need to turn the tenon to the farthest distance of the close-up focal length (about 88 cm on the scale), take off the close-up glasses, move the tenon around the small baffle separated at intervals to the general interval (above 1.5m or to infinity), and then take off the lens. Such a tedious explanation is to help readers protect the lens and fuselage on their hands. Although it is tedious, it is actually very interesting to play. Another suggestion is not to change the telephoto focal length on the fuselage as far as possible, because the lens barrel with telephoto focal length driven by DR is quite different (refer to Figure 2), and pushing the linkage focuser for a long time may also damage the function of RF. Of course, this is not confirmed by actual cases, but these words are also for reference. I've tried M6 non-TTL and DR myself, and it's ok to convert directly, but if you're afraid of damaging the fuselage, take off the lens first, bypass the tenon and then go to the fuselage (this is no problem), and remember not to wear glasses first, because the plastic baffle on the glasses will get stuck on the fuselage. (I said earlier that you didn't pay attention! ! A photographer in Hong Kong once pointed out that it is difficult to use the close-up function of the late DR lens on the M6 0.85x (#2296539) fuselage. Although there is no problem in installing the lens on the fuselage, a component inside the fuselage obviously hinders the close-up work of the lens. But I'm not sure whether all M6 0.85x fuselage will encounter this problem. Therefore, it is always a good idea to try M6 disaster recovery first. (In this early text, it is impossible to verify whether the fixed plastic has been removed, whether the M6 0.85x is a high TTL body, or whether there is a problem with the matching of glasses and lenses (lens barrel)? Or is it the problem caused by the big fracture in the back section of the lens barrel? It is hereby reserved for reference. )
-The fourth edition, 1969- 1979, is black (copper will not be exposed), the lens barrel is not printed with "50", and there is no focusing lever and lock, which is also called stilt five. The lens group was redesigned and changed into five groups of six lenses (the fourth and fifth lenses are each a group), and four pieces of glass LaFN2 developed by Lai Ci were adopted (note 1). This design has five flat mirrors, which simplifies the process of lens manufacturing and clamping. Because the double Gaussian structure has considerable residual aspheric aberration, although the contrast in the center is better than that in rigid /DR when the aperture is fully opened after effective correction, there will inevitably be some micro-mass degradation outside the center, but the imaging will be improved obviously after the second and third apertures are narrowed. It was first produced in Germany and later moved to Midland, Ontario, Canada (Note 2). The performance of this mirror is also very balanced, with better anti-glare ability and slightly higher contrast. Some people laughed that "every height should be strong" and the resolution was slightly reduced. Most users think that its performance can't be compared with the previous and later Summicron-M 50mm, and it has no obvious characteristics. The evaluation is good and bad, but the second-hand price is relatively stable. At that time, after DR, Summicron-M 50mm lens can focus on the nearest lens, but the nearest focusing distance is 0.7 meters, and the later version is also the limit of M-machine RF. Note 1: The text source is my Leica spindle head and optical glasses Note 2: A little information made by Leica in Degas (original).
-The fifth edition, 1979- 1994, is black (copper will not be exposed), and the lens barrel is printed with "50" and focus label. There are two shapes: crescent label and Tiger Claw, also known as crescent or Tiger Claw version. Until this generation, all Summicron-M 50mm still use external range hoods (those mentioned above). In order to reduce the contact surface between the mirror and the air, the lens group is changed into four groups of six lenses (the fourth and fifth lenses are combined into one group), which improves the imaging quality. The diaphragm blades have been changed from ten to eight in the previous version, and the weight is only 195g, which is the lightest of all Summicron-M 50 mm. The Summicron-M 50 mm with focusing lever was originally made in black and made in Canada. Later, it was collected by the Wetzlar factory in Canada, and the production line of 1986 was moved back to Germany (the new factory of SOLM, M6 started mass production almost at that time) (note 1), and some lenses were also produced in special edition and silver edition. Including 7 pieces (Summicron-M 35mm front ASPH) and Summicron-M 50mm, the production capacity is not much, and things are rare. In addition, there is the 70th anniversary edition of Leica released with M4-P, with the words "19 13- 1983" on the mirror body, with 800 pieces; It is sold with 200 special editions and the M6 commemorative machine in Colombo. By the way, M6 is also the M machine with the most commemorative money. For example, Hello Kitty's 20th anniversary machine. .................................................................................................................................. ........... has no information about the corresponding place of origin in the form of focusing rods (Note 2), and there is no information that the quality of this kind of mirror produced in Germany and Canada is different. It is considered that the focusing rod is only reflected in the change of material cost, and its optical properties have no obvious difference in the early and late stages. Note 1: The lettering of the lens can be slightly distinguished from the place of origin. It is produced in Wetzlar, Canada: LEITZ lens made in Canada, Leitz; Or made by SOLM in Germany: Leica (after 1986). The history of the factory mentioned in the second answer. Note 2: Also made in Canada, there are two kinds of focusing rods, figure 1: Canadian crescent version, figure 2: Canadian Tiger Claw version. Look from the serial number, Tiger Claw is earlier than the crescent, so it should be in the late Canadian or even German to make the crescent shape. Summicorn-M 50mm, fifth edition, used for a while before, with the design of focusing lever, it is very convenient to operate. After getting used to the focusing mode of RF, the eyes can focus and take pictures faster by using the position of the lever and the frame line of the view, sometimes even faster than autofocus, and of course it depends on the proficiency (attention). The optical quality of this edition has been highly respected, and even the next edition has not been changed, except for the part of the lens barrel. It is excellent in color reproduction, anti-glare, full aperture resolution and resolution from center to edge, and belongs to the model student type with excellent academic performance. At that time, I didn't expect that this version of the lens would have a great contrast. Compared with other newer lenses, such as ASPH lens, the contrast is still acceptable. Sometimes the contrast is slightly improved, but it can increase the three-dimensional sense of the picture. This is a very common skill in traditional or digital darkrooms. If you can skillfully operate this lens, you can say that the optical performance is almost impeccable. In color and black and white, the performance is quite remarkable, with a taste of seven pieces, except for the scattered scenery of course. (Personal) Note: Leica Finger Tab, the essence of Leica lens, can be known by referring to the description in the article.
-Up to now, the sixth edition of 1994 is generally called the current edition, with silver and black (copper will not be exposed), and the lens barrel is printed with "50", which is changed into a built-in hood, and the focusing lever is also cancelled, which is considered as slimming (together with the weight and volume of the hood). The optical design is the same as the previous edition, with 4 groups of 6 lenses, 240g black and 335g silver, and a small amount of spiral toothed plate produced by 1999, weighing 325g, which is quite rare. 200165438+February, Leica sold and produced 500 titanium Summicron-M 50mm lenses with a weight of 335g g. In 2003, 65,438+0,000 commemorative editions were issued to commemorate the 50th anniversary of Summicron-M 50mm 50 mm. The lens is made of the current version of the material and optical structure, and the appearance is the rigidity of the second version. The above is the general historical evolution of Summicron-M 50 mm. The sixth edition has not been revised for almost 20 years, and its completion level is roughly visible.