Leica Summarit-M lenses ( 2007)


Arguably the most important product announcement by Leica in a decade!

For a very long period admirers of the Leica system have argued and even pleaded with the company to produce a range of lenses that would be more affordable for the Leica user. Geoffrey Crawley showed his exasperation in a leading article when he noted that the proposal to Zeiss and Leitz engineers to design lenses that would not occupy the Olympic heights of the best of breed met with the reply: do you really want us to design lenses less good than we could make them? The success of the Canon approach with a two-tier design of lenses within the FD series (the normal high quality designs and the additional L-designation for the truly excellent designs) was noted as an example of smart engineering. Leica in particular continued to design lenses with a cutting edge approach and every single optical design was and is created with the goal to provide the best performance that money can buy.  
Leica has always claimed that high quality optical designs with a special focus on excellent performance wide open need special glasses, special surface treatment, accurate mounts, very tight tolerances and a careful manual assembly with copious quality control and individually machined parts that can be matched pairwise. 
It is certainly true that it is more difficult to ensure extremely tight tolerances when the production runs are small and a high level of manual control is required. It is easier to maintain a high level of quality and consistency in large production runs, because the manufacturing process can be constructed around the mechanics of high volume quality control and the availability of parts that are machined to the required tolerance by dedicated machinery. In large volume manufacturing the laws of statistical quality control rule and the whole manufacturing process is adapted to these laws. In small production runs, the laws of statistics can not be employed as it would generate a too high failure rate compared to the total output. 
The current state of the art
During the previous decade Leica has produce some of the finest lenses for rangefinder photography in the history, but they sometimes seemed to tend to cater for the tastes of the collector and not primarily for the working photographer. I remarked in 2005:

It is sad to note, but the focus on the collectors side of the business, may be part of the trouble. Leica has the habit of producing on an almost annual basis some products for the classically minded customers. The special editions for rich buyers and the collector-users of the LHSA may bring some welcome cash flow, but it also alienates the working photographer to recognize its true mission: the manufacture of a photographer's tool that satisfies the highest demands for high quality imagery.
Cosina/Voigtlander showed the way that designs that suited the working photographer, had a lower price tag, but delivered fair performance could become successful products. Optically the Cosina lenses were no match for Leica, but the performance of some of the designs is really good. Cosina had to create a manufacturing process that could lower production costs and stay within an acceptable level of manufacturing quality. It is a matter of debate whether the quality and the haptics can satisfy the Leica user, but it is a simple fact that the lenses do sell.

The introduction of the Zeiss ZM lenses opened a new chapter in lens manufacture and design. Zeiss proved that it is possible to combine in one lens design  excellent optical performance and a very good manufacturing quality with a reasonable price level. Zeiss used their approach of design relaxation with the Cosina manufacturing approach of component sharing, and simple component assembly with parts that have been designed for non-selective assembly and ease of fit during during the assembly stage. The innovation here is to adapt large scale manufacturing techniques to smaller production runs to reduce costs.
In my review of the M lenses I concluded that the Zeiss lenses are able to challenge the Leica designs without reaching that high level of performance wide open, but Zeiss is ahead in some design domains, especially flare reduction and the use of normal glasses to obtain a high level of optical quality. I summarized the state of the art thus:  
Germany's political problems and its industrial problems (Siemens giving away its cell phone (mobile phone) production to a Taiwanese company) signal a larger and deeper problem: the transition to a global production system and an internet-style economy and consumer power is painful, but a swift action is needed. The political parties and the majority of manufacturers in old Europe have no clue what medicine is needed. Leica is firmly rooted in the culture of this old Europe too.
There is no need to throw away the baby with the bathwater, the manufacturing values of old Europe are fine and the new Leica lenses are superb examples of traditional craftsmanship mixed with high-tech design and manufacture. But Leica needs to reinvent itself to fit into the new business model for the 21th century. The lost years cannot be recouped, but the creative potential in the company should be exploited quite soon. 
Leica lenses continued to offer superior quality at a high price level and now they got additional competition form their own lenses in the secondhand market, where one can buy excellent Leica lenses for a quite low price compared to the list price of new lenses. But Leica cannot make money in this market and has to accept the competition from their own legacy lenses. 
Leica's production capacity for the introduction of new lens designs seemed to be restricted to one or two lenses in a year. This slow pace can be explained by two different causes: the design philosophy of the company and the risk- and investment avoiding style of the Cohn/Coenen period. 
The Summarit-M range of lenses
The basic specs can be downloaded form the Leica website. All lenses have the same maximum aperture of 2.5. Actually it is closer to 2.4 because Leica wants to make sure that the indicated aperture is what you get on film or sensor. Cosina lenses often have physical apertures that are a quarter or a third stop slower than the indicated apertures.
All four lenses have the same look and feel with some differences. The 75/90mm lenses have rubberized focus rings that we also know from the current R lenses. In fact the outward appearance of these lenses has a strong resemblance to the R-line. They are beautifully designed with clean lines and a very functional look and feel. These lenses are optimized for manual focusing. The 35/50mm lenses closely follow the design pattern of the current 28/35mm Leica M lenses.
The mounts have a solid feeling, are stable without the slightest slack, and move smoothly (the feeling is very close to that of the f/2 designs). The click stops of the aperture rings have a secure positioning with just the right amount of resistance.
Accuracy is on the same level as the other Leica lenses. It is amazing to notice that the combination of new production methods and higher volume production has not compromised the traditional precision engineering for which Leica is famous.  
We may wonder how long the Elmar-M 2.8/50mm and the Elmarit-M 2.8/90mm will stay in production.
The optical cells are different for every lens, but the mounts and some other parts are shared per pair of lenses. The new 2.8/28 lens has shown the direction that Leica is taking to provide high class lenses at a reasonable cost by employing new manufacturing and production techniques. (Leica did study the competition closely and there is nothing wrong with this: Leica has a historical record of being a great improver, more than being a great innovator).
For every lens Leica took the existing design of the Summicron designs as a starting point and optimized the design in relation to the smaller aperture (2.5 versus 2.0) and using standard glasses. It is well known in the optical literature that a small selection of the 200+ glass types available on the market can be used to design most lenses.
The assertion of Zeiss that it is possible to create excellent designs using this small selection of standard glass has been substantiated as is the claim by Leica that one needs extraordinary efforts to produce wide aperture top-class designs, like the Summicron and Summilux ranges. Exotic glass types do require exceptional surface treatments and very careful mounting and adjustment procedures, processes that are very expensive in time and material and equipment.
The really exciting fact is the production Standort: it is Germany, Solms and not Japan!
The difference in image quality between the Summarit and the Summicron lenses is not easy to detect. (The older Summarit 2.4/40mm for the compact Leica camera Minilux was as good as the Summicron 2/50mm!).
The Summarit range has been designed to provide a very low level of flare and secondary reflections, one of the areas where Zeiss could beat the Leica lenses. Tests are needed to support the claim, but it is significant that Leica has stressed the fact itself.
The lenses are designed for use with the classical 35mm format and per definition for the M8 too. The Summarit range can be used on all M cameras, including the M8 (with the reduced angle of view and no change in magnification as is still often claimed). The properties of the lenses are for use with the 35mm format and are not attuned to the reduced angle of view of the M8 image capture. And all four fall within the optimum range of focal lengths for the Leica rangefinder camera, as explained in my previous viewpoint. 
The differences between the Summarit and Summicron line.
It is indeed amazing to see how much effort is required (optically and mechanically) to deliver optimum performance when the maximum aperture is just a half stop wider.
Apart form the different assembly and manufacturing technology, Summicron lenses have a long list of high-end properties like apochromatic correction, aspherical surfaces, exotic glass types, floating elements, and can focus more closely. Build quality is also a notch better and the selection of materials is different to ensure durability and longevity and accuracy under all conditions. Here the Summarit line has to prove itself over time.
Weight and size differences are as follows: (length, width, diameter, weight, close focus range, price)
Summicron 35 = 34.5; 53; E39; 255 gr; 0.7 meter; Euro 2150
Summarit 35 = 34.0; 51.4; E39; 220 gr; 0.8 meter; Euro 1250
Summicron 50 = 43.5; 53; E39; 240 gr; 0.7 meter; Euro 1450
Summarit 50 = 33.0; 51.5; E39; 230 gr; 0.8 meter; Euro 1000
Summicron 75 = 66.8; 58; E49; 430 gr; 0.7 meter; Ero 2395
Summarit 75 = 60.5; 55; E46; 345 gr; 0.9 meter; Euro 1250
Summicron 90 = 78; 64; E55; 500 gr; 1 meter; Euro 2595
Summarit 90 = 66.5; 55; E46; 360 gr; 1 meter; Euro 1250
These differences can be gleaned form the specs, but the assessment of actual performance differences has to wait until comparison tests can be done. 
The introduction of a suite of four lenses for the M at one point in time is quite unique for Leica. The Leicaflex was announced with four lenses too at the same moment of introduction (35mm to 135mm), but that is as far as I know a once only event in Leica's history. Until now. The new methods of manufacture and assembly allow a lower price and a higher volume production. Manual labour is very expensive in Germany and it slows down production speed. 
The price level of the Summarit range must be set into perspective. For a true Leica lens it is really a bargain, but a price tag of around Euro 1200 will buy you a very decent DSLR with a wide range zoom lens. 
For a long time one would have assumed that a lower cost lens line would have to be fitted with a maximum aperture of f/4. But the Summarit range has a uniform maximum aperture of f/2.5, only one half stop less than the Summicron line. This small difference might pose a problem within the Leica lens system: the Summarit range might cannibalize the wider aperture lenses. A first analysis of the performance of the Summarit lenses indicates a quite high level of performance, but the fingerprint of these lenses shows enough differences with the Summicron lenses to warrant the side by side availability and use of both systems. The Summarit lenses are exquisitely suited for general use and for longer holiday trips as the set of lenses including one or two bodies (M8 and M7) fits into a compact bag.  For heavy duty use and for image quality with great finesse the Summicron range will be the premium choice. 
The announcement and availability of the Summarit range lenses indicates a major, if not a fundamental change in the design/production philosophy and marketing approach  of the Leica company. The Leica future looks bright at that is good news. 
Aperture facts
The true aperture numbers are as follows in a range of 0.3 and 0.5 stops
full stop: 2.0000
+ 1/3 stop: 2.2449
+ 1/2 stop: 2.3784
+ 2/3 stop: 2,5198
full stop: 2.8284 
Lens designs  

The Summarit name has been historically used for the 1.5/50mm standard lens, then a derivation from a Schneider lens design. Leica historical researchers differ in their assessment if this Summarit design is an original Leitz creation or just a renamed Schneider Xenon 1.5/50mm. This original Summarit design did not represent the state of the art of the day for high speed lenses. Leitz used the name Hektor for the 2.5/50mm design by Berek, but also for a 4.5/135mm lens. The Summarit designation got a new beginning with the Summarit 2.4/40mm and this lens design gave excellent performance. The new Summarit range may be positioned as the successor of the Elmar and Elmarit lens lines. Leica might settle for three ranges: very high-speed designs that represent the best performance in this domain and designated Summilux, high speed lenses with superior definition and designated Summicron and  all-round lenses designated Summarit. With the current quality of the 2.5 designs, there is no need for a 2.8 range. 

All four look familiar, especially the Summarit 50mm is a clone of the 2/50mm, but note that the lens elements around the aperture stop have a smaller diameter than in the Summicron version. The 35mm has the front and back lens groups reversed, loses one element (the negative curvature element). The 75mm too loses an element and the 90mm is a very close relative to the original 90mm lens from 1980, the Summicron III!