Quote Originally Posted by Sirius Glass View Post
Get a copy of Vade Mecum,a lens collector's vade mecum* by M. Wilkinson and C. Glanfield

*Vade mecum: Eng. a book or manual suitable for carrying about with one for ready reference(1629): a casket set by Busch (1890's).
For example:
E. Leitz, Wetzlar, Germany
also at Midland, Ontario, Canada from 1955.
E. Leitz was established initially as a microscope maker, and only offered camera equipment many years later. This may have begun from the need to supply equipment for photography through microscopes, and for low magnification work separately from them. Thus they seem to have developed a limited programme of high quality lenses from about the early 1900's. These were regarded in the trade as normal photo lenses rather than specialized items for macro or like use. In the 1920's they expanded into making enlargers, and selling lenses, notably on Nagel cameras, so that they were well placed to develop a programme for the 35mm camera which they introduced in about 1924. This relied on a precisely made body and sharp lenses to allow substantial enlargement, the limiting factor being the film then available. One reason may also be that for microscope photography, the small format would record all the detail available without the longer exposures needed for a larger but less well illuminated negative. They would be well aware of the "empty magnification" feature this can involve.
Early Lenses
Summar f4.5 24, 35, 42, 64, 80, 100, 120mm This may be a 6-glass Gauss type, (Frerk's comment) or an air-spaced Dagor type? (Lei001). This was shown in an early pamphlet and it is unclear how long it was sold. They show 8-air-glass reflexions with little sign of extra reflexions, which rules out extra spacing or even cemented surfaces. However it does seem that by the 1920's there was a new type. Thus it is thought that the design changed to a 4g/4c dialyt of equal performance in later years. These lenses do not seem to be numbered, and may be continued later than first thought in brass finish, as some are in M39x26 adaptors suggesting a post-Leica date, but a black finish 120mm example has also been seen. It was recommended to use 120mm on 9x12cm, 64mm on 6x6cm. In 1908 they were listed as Portrait lenses, with the f5 as a lens for groups and general outdoor work. The smaller examples such as a 64mm were listed as f4.0 in a B&J list. Several f4.5 lenses have been seen. The iris graduations are unusual, the f4.5/120mm being graduated from 2 (about f4.7) to 96 (about f32), the 80mm stopping merely to '24', about f16. Early examples are in lacquered brass, later in black enamel. A 120mm lens was used on a 6x9cm camera and gave
attractive negatives of good quality but fairly low contrast.
Fig 015 034 Leitz Summar lenses (l + r) Summar f4.5/120mm and (mid) Summar f4.5/80mm.
Summar Series 11 f5.0 95, 115, 135, 150, 180mm (Layout Lei002) This seems to be a less common series from the few examples seen. It was also made as:
Summar Series 11 also f6.0 150, 180, 210, 240, 270, 300mm (Layout Lei003) and this was the version Frerk knew. It was suggested to use 135mm for 9x12cm. (B.J.A. 1909, p696, 697).These are convertible to work as long focus lenses. The only example seen was a f6/135mm and was in a shutter, and no serial number could be seen. (The front cell was rather lightly engraved and the paint was badly worn.) It seemed to be a 4g/4c design, possibly a dialyt. The reflexion pattern was like the f4.5 in having 8 bright reflexions, but here two were very close together at all times on the 135mm lens seen.
Periplan f7.7 90, 120, 150, 180, 210, 240mm (Layout Lei004) This can be seen as a version of the Q7 anastigmat. Use 120mm for 9x12cm.
For all these, use a 7in lens for 1/2plate. The covering power of Periplan was nearly as big as the Summar, and it was a good deal cheaper at 3.oo compared to 4.5o for the Summar. (B.J.A. above."We can strongly recommend the "Periplan" to anyone requiring a cheap f8 lens.")(Anon): see B.J.A. 1900, p865 for a 3+1 type lens eg as a 240mm f8.0. Production of this seems not to be known.
Writing in 1926, Frerk says these were discontinued, but high quality items and useful secondhand. He does not "know" of the Elmar though the new Leica camera just got into the book, probably at the proof stage. Milar f4.5 25-100mm This was essentially a macro lens, using the Triplet layout. It was a very long lived product, still being produced well after 1945 for macro work. The layout is near Q13 with the front two glasses near together. The f4.5 50mm version was used on at least one Leica prototype. Note that Leitz also made or used triplets for cine use under the trade name "Dygon" both before and after WW2.

Fig 015 030 Leitz Milar f4.5/50mm. This seems to be a fairly modern lens with a red dot to match the 'M' series lenses.
Dygon f2.8, f3.5 20mm. This was a postwar lens, noted on Leicina 8S, also Leicina Vario. Most of them seem to be f2.0 as two Dygons f2/15mm and f2/9mm No1,794,33x on a Leicina and a posibly 'special' Leicina had a complete set of f2/9mm No1,858,86x; f2/6.25mm No1,939,68x; f2/36mm No1,981,16x and f2/15mm (incomplete).
Variogon Many Leicinas carry these and they are thought to be derived from Schneider. One Leicina 8S had Dygons 9 and 15mm. Angenieux Zooms such as Type K2 7.5-35mm at No1,079,32x are also used.
Aplanat There have been rumours of an Aplanat, =RR, possibly of projection origin. No details are available at present. Several other German firms used this layout for projection lenses until about 1920 or even slightly later.
"Studio" In the 1960's, B&J listed a single old Leitz f3.5 150mm lens in a Studio shutter: this seems to be an unknown lens otherwise.
Subsequently the Programme was dominated by the Leica camera. It is a very impressive experience to use an early Leica with modern film and see just how good the older lenses were. For choice this would be an Elmar on a fixed lens camera- or an early screw lens body with several Elmar lenses. Venturing outside the Elmar series prewar is a more mixed user experience and it is suggested that for users some caution is worthwhile before paying the larger costs of some of the other old lenses which are valued as collectors items rather than for use. Postwar the Leica lenses rapidly reached and indeed set a consistently high standard and can be recommended without the same reserve.
35mm lenses
The first and most famous of the original lenses for it was the 50mm f3.5 as follows. It was designed by M.Berek (1886-1949) who worked for Leitz from 1912, and while primarily a microscopist, designed the original lens line.
The layout of this famous lens was roughly Q15 but the initial patent covers a lens with a front glass designed so that the fundemental rays cut the axis near the front lens. (D.R.P. 343,086/1920). This led to a preferred iris position nearer the front than usual, and it is between glasses 1 and 2 in most Elmar 50mm lenses, and to a less curved interface in the rear element. The detailed design seems never to have been fully realized commercially, as it featured a movable second glass to allow for correction of astigmatism in close-up, and

perhaps since the external glasses were of rather soft DBC. The next development was a 5-glass type, which would not have fallen within the patents of the Q15 type and which may have eased the glass requirements. Finally a glass from the Sendlingen plant of Goerz allowed the design of a Q15 type lens of f3.5 aperture covering the whole of the 24x36mm frame. This was a new standard in 1925, and may have used features from the above patent. It has been suggested that when Zeiss produced the f3.5 Tessar, the patent position was sufficiently balanced for the firms to act independantly but without complaining if there was a possible overlap.
The Elmar designer was Dr Berek, and the lens had to be heavily modified about 1929 as the Sendlingen plant was then converted to produce other products and all optical supplies were taken from Schott. (The change followed the unification of Zeiss Ikon in 1926.) As a result, the new type has a visibly flatter front curve, and came into use about the time when the Leica Standard was introduced. Note that the iris position was kept in the same place in the new model, except when these are mounted in blade shutters for the small number sold in Compurs essentially for the Leica, Vollenda and Pupille cameras. These show the impressive covering power of the Elmar since in the rollfilm versions it is covering 3x4cm and still works well.
Many years later, Leitz were to redesign it again with "new rare earth" glass and show the change as the new red scale version. It is worth noting that the 'old' Q15 type did involve some compromise in the colour correction, less serious in the days of ortho films than it was to become later. This lead to the use of the Hektor type of layout to replace the 135mm Elmar lens, and the choice of a (rare) 50mm Varob-Hektor version for enlarging colour material. But the Elmar was the mainstay of the Leica for many years in its various forms, especially the 50mm lens, and still is a fine lens to use in any form.
Incidentally, the '50mm' covers a range of foci shown by number codes on the early lenses but typically they were about 51-52mm focus. It is likely that one factor was that this was easier to use to get good overall sharpness on 24x36mm as wide field designs at f3.5 were then hard to design. But Barnack's experience using movie lenses with imperfect cover on the bigger format will have helped to push the choice this way. Note thart a movie photographer would expect to use about a 3 or 4in lens on this format. G. Crawley in B.J.P. 24/01/1996 p23 mentions another point. That microscope lenses were in inches (=25.4mm) and Leitz will have tended to design Milar and similar lenses microscope lenses made to this focus, ie of 50.8mm. It is also true that makers do allow themselves some leeway in the choice of foci around the engraved value, though here Leitz always would measure and record the true value and tell the customer if needed, and later were to engrave the last 2 digits on the barrel.
Essentially Elmars
Leica Anastigmat f3.5 50mm Some of these are 5-glass versions and are so rare that they are seldom examined to see if they really are of this type. What is certain is that the number is very small and that they are very inaccessible to the normal lens collector.
Elmax f3.5 50mm Essentially these seem to be optically the very first set of 4-glass Elmars, but it is still not certain when the change over ocurred. The change of name does not necessarily coincide. (Layout Lei012, 5-glass; Lei005, 4-glass)
Elmar f3.5 50mm This was a Q15 type lens, and the uniquely sharp lens which made the Leica reputation for sharpness. It can be used on up to 3x4cm, and as an enlarging lens 'Varob' and Leitz considered it for projection work, both as camera lenses fitted in the 1930's to slide projectors, and sold postwar in custom fitting for the job. (Layout Lei005, 006)
Elmar f3.5 35mm Layout Lei011 This is a very compact and useful semi-wide angle lens, rather less sharp perhaps than the 50mm version and with more fall off in image quality in the outer parts of the field on 35mm. But the value outweighed any shortcomings.

Elmar f4.5
Elmar f2.8
Elmar f4.0
photography, and has always been a favourite. The focal length is one which suits the design very well and it was not challenged till it could be replaced with a rare earth design in the 1950's. Some early lenses are in a much more bulky and heavy mount commonized with the longer lenses and and these are described as 'fat' while soon the same lens was offered in a slimmer and lighter tube and this proved to be the long lived product.

35mm A prototype which was illustrated, listed but never sold.
35mm (This was a prototype for 1/2frame use and not a commercial item.) 90mm Lei010 This was the first medium focus lens for 35mm still

Elmar f6.3 105mm The Berg or Mountain Elmar was designed as a light item for travellers and climbers- hence the name. It needs care in use as it is slower and there is more danger of camera shake- hence the slight question that has been raised over its sharpness. (Lei009)
Elmar f4.5 135mm A longer lens in full weight mount. The earliest were not coupled to the Leica rangefinder- this also is true of some other Elmars- and the mounts do vary in detail. It should be a

sharp lens but the focus is long enough to begin to show up design limitations in the Q15 type. Prof. Berek therefore designed a new lens called the Hektor to overcome this limitation and it is the preferred item especially for colour work. The longer Elmars may actually be derived from designs for large format lenses for 6x9 (105mm) and 9x12 (135mm) and have been reported on Nagel cameras. (Lei008).
It is not quite clear what other Elmar lenses were made as Leitz enlargers of the period were fitted with anonymous lenses such as VOORT f4.0/95mm and these may include other focal lengths in this design area. One example was an enlarger for 4x6VP format with a lens of some 7.5cm. Incidentally Leitz provided for the longer lens heads to be removed for close-up work on copiers, etc. and they were and are very useful for this.
Hektor- An improved Elmar
During the early 1930's the programme of Elmars was extended by a series of more ambitious lenses with extra glasses, especially in the centre of the Triplet. Leitz were to use these in one form or another for many years, the last being as projector lenses long after WW2. It must be stressed these were designed both for greater speed, but also sometimes for wider angles or greater sharpness and that this is a design where Leitz were successful but few other designers have chosen to follow. In all cases they can be related to the triplet by compounding one or more components. This avoids extra air-glass surfaces but at the cost of rather limited design freedom.
(a) The centre glass was the only one doubled in the 135mm f4.5 Hektor, which replaced the 135mm f4.5 Elmar. The Hektor is generally regarded as an improvement, especially for the colour correction, and without any penalty. (Lei024)
(b) Both outer glasses were compounded in the 28mm f6.3 Hektor. Again this was a real success, offering a nice compact real wide angle lens of good sharpness and even illumination. [Most users would rate it ahead of the comparable Zeiss 28mm f8.0 Tessar of the same period. (Lei020)]
(c) The other two Hektors have all the three glasses compounded and are more controversial lenses. At small apertures they are extremely well corrected, especially for colour. But at large apertures the contrast falls off quite noticably due to the apertures of f2.5 for the 50mm lens (Lei021)and f1.9 for the 73mm one.(Lei022) They can do good work at full aperture, but really are best only under contrasty conditions where the under corrected spherical aberrations do not reduce the image contrast too much. This is really the sort of lens where the older workers carefully advised giving a minimum exposure, although they may not have always understood why this was essential. The Hektor may have been patented under USPat 1,939,098 of 12/12/1933 which uses glasses G1= 1.624/58.2; G2+5= 1.603/38.0; G3= 1.665/35.7; G4= 1.581/40.8; G6= 1.656/51.4. But Merte quotes a version with G1+6= 1.6190; G2= 1.6100; G3= 1.6750; G4= 1.5890; G5= 1.5290. Mr Cook (Photo Jnl Oct 1949 shows curves for the 73mm Hektor's correction. The field is fairly flat with quite a lot of astigmatism at up to 2% of the focal length at 17 and the spherical aberration is rather heavy, and continues to quite small apertures, giving a perceptible fringe round details. He comments that this type of correction can give detail under contrasty lighting conditions but falls down badly in low contrast subjects- (which is why soft focus lenses are used in portraiture!) A Hektor was occasionally used other than on a Leica: it has been noted on a Mentor Dreivier at No150,691, and a few were used for color enlarging as Varob Hektors f6.3- iris opening being limited to f6.3.