Tuesday, November 2, 2021


Text and Pictures by José Manuel Serrano Esparza

Unlike the M2, M3, M4, M4-P, M6 and other Leica M rangefinder cameras that used control cams and timing devices featuring gear trains to govern the focal plane shutter, in the Leica M7 that mission is accomplished by two little magnets, a key factor to attain the aperture priority automatic exposure control which is its most significant trait. 
© jmse

The great versatility of the four-part Leica M mount, a brainstorm by Hugo Wehrenfennig in early fifties, providing it with the best feasible shape to achieve that the maximum quantity of light coming from the optical system of the lens could reach the outermost corners of the image, has been instrumental to enable the coupling of a hugely comprehensive array of lenses from other brands and different times to 24 x 36 mm format Leica M cameras from 1954 hitherto, also built with that landmark mount featuring an external diameter of 44 mm and a flange distance of 27.8 mm, and even German and Japanese very old lenses in LTM39 mount through dedicated adapters with M bayonets which activate the corresponding bright-line frame in the camera´s viewfinder.

And it has sometimes spawned unique combos like this Leica M7 with W-Nikkor·C 2.5 cm f/4 wideangle lens in LTM39 mount, emboding a flawless synergy between one of the evolutive pinnacles of the Leica M saga of rangefinder German cameras and a gorgeous and very small Japanese pancake design wide-angle prime whose 4 elements in 4 groups optical scheme, incepted by the Nippon Kogaku Japanese optical designer Hideo Azuma, dates back to 1953 and lacks any focusing ring.

The Leica M7, launched into market in 2002, is probably the 35 mm analog rangefinder camera featuring more functions ever made by the German firm, with a core made up by a very accurate rangefinder, three choices of viewfinder magnification (0.58x for wideangle lenses, 0.72x as universal standard magnification, and the 0.85x version for lenses with medium and long focal lengths up to 135 mm, with brightline frames designed accordingly for each magnification and being manually or automatically activated in the viewfinder), and an electronically controlled, vibration free and horizontally running state-of-the-art focal plane cloth shutter working extremely smoothly and practically without vibrations, it all being fostered by a very reliable TTL semispot metering, which is slightly more accurate than the very precise one featured by the Leica M6 and Leica M6 TTL.

All speeds are electronically governed, except 1/60 sec and 1/125 sec, which are mechanical, in such a way that we have got security margin to spare, because if suddenly the batteries drain, we can use either of these speeds to get the picture.

The tiny size and amazing beauty of the W-Nikkor·C 2.5 cm f/4 wideangle lens is apparent in this front view of the Leica M7 attached to it. An external metallic Voigtländer optical viewfinder with brightlines for 28 mm and 35 mm lenses has been installed on the camera hotshoe. In addition, the Leica M7 coupled to it features a 0.58x VF magnification, optimized for use with 28 mm objectives, so it also works flawlessly with the Japanese 25 mm wideangle lens. 
© jmse                    

Aside from the traditional manual selection of shutter speed and aperture by means of the light balance in the viewfinder, which has been thoroughly proved for a lot of decades in preceding models of Leica M cameras, the M7 also sports the automatic aperture priority choice, which enhances even more the great quickness of usage based on a highly precise large base RF enabling very consistent focus once and again, even with low contrast objects and under very dim light conditions, helped by the top-notch high luminosity of the slew of Leica M lenses, excelling in terms of optical and mechanical quality and rendering exceedingly high resolving power and contrast even at the greatest apertures for which their design was usually optimized, bringing about crystal clear images, loads of detail and great colours.

A quality without compromise, far from any programmed obsolescence and a true photographic tool to last a lifetime, lacking lots of buttons or knobs, and in which the photographer has got the control at every moment and takes the decisions on the keynote of paying attention to the essential and really important things, for tackling the photographic act with the least ammount of clutter, in an unobstrusive and inconspicuous way.

In addition, there´s often the further chance of using hyperfocal techniques and running the show as to the desired depth of field area, beating in accuracy and speed the best AF of professional analog and digital SLR and mirrorless cameras in genres like candid shots or street photography.

Diagonal left view of the Leica M7 with W-Nikkor·C 2.5 cm f/4 wideangle lens showing the remarkable compactness of this camera/lens symbiosis. The camera highly sophisticated electronics created by Robert Denk, Stephan Staudt, Christian Fornfeist and Rolf Magel brought about a huge manufacturing and development effort to preserve the pretty small width and depth inherent to Leica M camera bodies along with their external appearance, while simultaneously being able to get every mechanical part and electronic component inside it, so new technologies had to be implemented to achieve that goal. Thereupon, the members of the Leica M7 Development Project, supervised by Otto Domes and Stefan Daniel, rose to the challenge and managed to fulfill a state-of-the-art miniaturized engineering that made possible an increase of only 2.5 mm in the height of the top plate and to keep the gist of the only camera concept on earth that has remained loyal to its original roots and philosophy for seventy years until now, since the patent of the Leica M mount was presented by Hugo Wehrenfenning in Wetzlar in 1950, bringing into play a decisive synergy with the basic range-viewfinder with bright-line frames of the Leica M System pioneered by Willi Stein and Dr. Ludwig Leitz in a patent of 1941 and which would come to fruition in 1954 with the Leica M3. 
© jmse                        

If we also bear in mind that the Leica M7 shutter lag is of only 12 milliseconds (much shorter than the shutters sported by current top-of-the-line SLR and mirrorless digital professional full frame cameras), we get the hang of the whole thing: to take pictures with the Leica M7 is something more spontaneous, relaxed and convenient, using a very compact and light camera body, along with tiny lenses most times second to none in optomechanical quality in the 24 x 36 mm format domain.

On the other hand, it generates a very low level of noise when shooting, comparable to a whisper (the Leica M7 beats in this regard the already extremely silent M3 and M6 when using slow shutters speeds, while when getting pictures at medium and high speeds the almost imperceptible levels of noise are on a par), the latter being feasible because instead of the levers, cams and gears driving the speed adjustment in classical Leica M cameras like the M3 and M6, an electromagnet for each curtain is now responsible for the timing of the shutter release, and the absence of the gear train present in classical Leica M models bringing about a very slight noise during the delay of the second curtain when using slow speeds, turns into silence with the M7.

Besides, a new rollerbearing strengthens the main roller of the M7 shutter, and it makes a difference regarding its precision and seamless duration under stress throughout many decades, with a remarkable speed steadiness of the traversing slit.

The shutter of the Leica M7 operates flawlessly and boasts higher accuracy than the different models of mechanically governed Leica M rangefinder cameras, though in extremely harsh environments over 60º C and under -30 º C the utterly mechanical shutters featuring Willi Stein, Ludwig Leitz and Peter Loseries DNA will work impeccably, whereas an electronic shutter could not operate.

Regarding flash synchronization, the Leica M7 has the possibility of being used with appropriate flash units set for the first or the second curtain, with the added benefit of a high speed sync choice.

It is a camera built with a smart mixture of old and new product technology, oozing a very painstaking care devoted to the design of the viewfinder, shutter and the die-cast housing, with a tremendously exacting material selection and treatment, engineering quality and an almost entirely manual assembly following painstaking artisan guiding principles.

Top view of the Leica M7 coupled to the W-Nikkor·C 2.5 cm f/4 wideangle lens. The minimalist upper panel of the camera shows from left to right the automatic frame counter, the shutter release button with threaded socket for cable release, the quick-wind lever for film transport and shutter wind, the shutter speed dial, the Voigtländer external VF for 28 and 35 mm lenses, and the angled rewind crank. The incredibly small size of the Japanese wideangle lens, which barely protrudes from the camera body, is also visible. 
© jmse

Needless to say that the M7 is a milestone in the Leica M breed development, needing a three years groundwork that began in January of 1999 in Solms (Germany) with meetings between product manager Stephen Daniel and some professional photographers from whom he gleaned abundant feedback, until the camera came on stream in 2002.

And in spite of being an analogue camera, it harbingered in a number of aspects the subsequent development from 2009 onwards of the full frame digital rangefinders Leica M9, M10, M10-P, M10 Monochrome, M10-R and others, being the conceptual forebear of them all.

On the other hand, the possibility opened by the M7 of choosing automatic aperture priority allows the photographers to attain a more spontaneous and relaxed photographic activity, since they are not bound to be aware about setting the correct exposure or to adjust it, in frequent contexts in which light conditions are changing, so they can pay attention to framing, composition and focusing, immediately after having selected the subject, because when aperture priority AE is on, the camera constantly measures the light.

It´s clear that a Leica M experienced photographer will be able to make things without problems with a mechanical Leica M3, M2, etc, guessing exposure through estimation, often using the sunny f/16 rule and operating quickly without any built-in TTL metering and getting a high rate of accurate focusing and much better pictures than a bad photographer with a Leica M7, and that the aperture chosen will go on being a very important aspect to control depth of field, selective focusing and picture quality.

But with the Leica M7 the option of relying on a well proven electronic system which makes the task of selecting the appropriate speed in a very fast way, undoubtedly liberates the photographer of the work and time necessary to manually set the shutter speed with previous Leica M cameras, while you go on preserving the control of the significant items and taking the decisions with a minimum intervention of electronics.

It is also apparent that sometimes a picture of a brief moment is missed because to manually set the correct exposure means to take some time and then that instant may have elapsed, so the advantages of the M7 in this respect, with its available aperture priority AE can be significant when the photographer has to tackle environments where he/she must react fast under changing luminic levels.

On the other hand, the sturdiness of the Leica M7 and its ability to endure a lot of years of hard professional use is impressive, because only high quality materials are used in its manufacture.

One example will suffice: its top cap and base plate are made with solid brass, while the camera body consists of very special simultaneously light and highly tough diecast aluminum.

A riveting sight : W-Nikkor.C 2.5 cm f/4 in screwmount fully integrated in the Leica M System thanks to the LTM39 to M adapter. The distance scales in feet are engraved in black colour on the big metallic ring surrounding the lens barrel, while the depth of field scales in white colour can be read on the metal lens barrel itself. The chrome finish of this Nippon Kogaku Japan wideangle lens is superb and enhances its stunning overall beauty. 
© jmse

The 4 elements in 4 groups W-Nikkor.C 2.5 cm f/4, designed by Hideo Azuma in 1953, and clearly inspired by the Zeiss Topogon 25 mm f/4 for 24 x 36 mm Contax rangefinder cameras, is a minute jewel in itself, with very small dimensions and weight rendering it a relish to use shooting handheld.

Obviously, it is far from the optical performance of much more modern optical designs of similar focal length and maximum aperture around f/4 featuring multicoatings like the not coupled Cosina Voigtlander 25 mm f/4 SC Skopar for Nikon and Contax rangefinder cameras (and also for screwmount Leica rangefinders and Leica M cameras through adapter), the coupled Cosina Voigtlander 25 mm f/4 SC Skopar in Leica M mount, and differences would be much bigger in all conceivable parameters if comparison are made with the superb Elmar-M 24 mm f/3.8 ASPH or with the trio of reference-class highly luminous 24/25 mm wideangles made up by the Elmarit-M 24 mm f/2.8 ASPH, the Zeiss Biogon T* 25 mm f/2.8 ZM and the Summilux-M 24 mm f/1.4 ASPH, all of which hugely outperform the W-Nikkor.C 2.5 cm f/4, a lens created almost seventy years ago.

But it doesn´t matter at all, because this charming wideangle Japanese vintage lens is much smaller and lighter than all the aforementioned top-class wideangles in the 24/25 mm realm, and it is still able to get good pictures, so the photographer using it can attain virtually unsurpassed levels of compactness, convenience of transport and comfort shooting handheld coupled to the Leica M7, to such an extent that probably only the 5 elements in 3 groups Hektor 28 cm f/6.8 in LTM39 mount (1935-1955), the 6 elements in 4 groups Summaron-M 28 mm f/5.6 (1955-1963) and the modern Summaron-M 28 mm f/5.6 ( launched into market in 2016 with identical optical formula and length of less than 2 cm, but far superior optical glasses and delivered image quality ) would approach the vintage Papanese wideangle lens in those aspects. 

If besides we realize that the W-Nikkor.C 2.5 cm f/4 only protrudes 0.95 cm from the camera and that it is possible to shoot hand and wrist at very slow shutter speeds of up to 1/4 sec without trepidation using first-class modern 35 mm black and white films like Fuji Acros 100, Kodak T-Max 100, Kodak T-Max 400, Argenti Nanotomic-X shot at iso 100 and 200 and developed with Nanodol, etc, along with current iso 100 color films like Kodak Ektar 100, Fuji Reala and iso 400 colour film like Fuji 400H, Kodak Portra 400, etc, with the chance of greatly improve the image quality possible during fifties (in which chemical emulsions were much grainier) preserving that very special aesthetic of image inherent to classic Nippon Kogaku rangefinder lenses from the starting halcyon days of Nikon during fifties, we begin experiencing unique sensations.

The elegance and charm of this camera / lens combination is truly outstanding, merging two products which were manufactured roughly 50 years apart from each other but share a quest for great cosmetic beauty, top quality of materials used, the best possible optomechanical level for their time and a commendable stability and comfort shooting handheld with maximum unobtrusiveness. 
© jmse

This was a Japanese great optical tour de force design, because 68 years ago it was strenuously hard and difficult to design a small extreme wideangle lens for the time like this, featuring such a little diameter, and the manufacture of its four elements became an exceedingly hard toil, specially the two very thin and brittle concave elements of its optical formula, whose treatment was very cumbersome.

On the other hand, each W-Nikkor·C 2.5 cm f/4 produced needed a very special cleaning equipment during the manufacturing stage.

Hideo Azuma, a great optical designer working for Nippon Kogaku, studied very thoroughly the four elements in four groups German Carl Zeiss Topogon 25 mm f/4 for 24 x 36 mm format Contax rangefinders, created three years before, in 1950, and decided that the 1953 W-Nikkor·C 2.5 cm f/4 wideangle lens would be based on it, as well as inheriting the deep aperture ring set from inside the lens.

Aerial diagonal left view of the Leica M7 attached to the W-Nikkor·C 2.5 cm f/4, whose focusing is silky smooth. Since the lens is recessed so far into the mount, to attach a hood to it is not as indispensable as with most 24 mm and 25 mm wideangle lenses. 
© jmse

It quickly dawned on Hideo Azuma that the creation of the new Nippon Kogaku superwide angle lens (the focal length of 25 mm was then deemed as that in the 35 mm format domain) would be a very strenuous optomechanical task.

Moreover, the optical firms in the post II World War Japan were on a shoestring budget and needed to use not very expensive glass to reduce designing cost, so it was impossible to get professional image quality at full f/4 aperture with this kind of objectives.

But there were two important advantages: on one hand, such a wideangle lens is most often used at f stops between 5.6 and f/11, and on the other hand, the Topogon design, though not being a very luminous one, allows to obtain an extremely flat field boasting complete wiping out of astigmatism even using not the best and expensive glasses, and besides, it doesn´t need top-notch and also pricey antireflection coatings intended for the preservation of the glass from a chemical viewpoint as happens with other not Topogon modern wideangles in the range of 24/25 mm and featuring wider apertures of f/3.5, f/2.8, f/2, etc.

Another top view of the Leica M7 camera coupled to the tiny W-Nikkor.C 25 mm f/4 lens. We can see that the shutter speed dial presents three new features in comparison to previous Leica M cameras : two specific marks for 2 seconds and 4 seconds (located between 1 second and B) and an Auto position (between B and 1/1000 sec) to select aperture priority. In addition, Leica also upped the ante with the shutter speeds of this dial, which were engraved mechanically, so they will be perfectly readable after many decades of intensive use, without forgetting the impressive manufacturing thouroughness of the camera top cover for which some new and different breakthrough CNC controlled milling machines were used with noble metals like brass. Though it caused a bit of stir when it appeared in 2002, since it depends on batteries for the operation of its new electronic shutter and boasts automatic aperture priority exposure, the Leica M7 is also a prodigy of mechanics regarding its inner space and global working, with nothing less than 1,350 individual parts and profusion of screws, springs, small plates, levers, gearwheels, eyelets, pins, etc, so the mechanical operational notion of classical Leica M cameras has mostly been safeguarded. 
© jmse

This way, Hideo Azuma devoted himself full blast to the designing of the W-Nikkor.C 25 mm f/4, doing his best to emulate the Zeiss Topogon 25 mm f/4 for Contax rangefinders, but with very few means and a short array of optical glasses available, using the same optical formula of 4 elements in a symmetrical design, optimizing the performance for f/8 and f/11, in addition to balancing as many factors as possible by means of hard work and a lot of tests, opting for maintaining some coma, spherical aberration, some residual flare specially at the widest aperture and some chromatic aberration.

Therefore, at full f/4 aperture the lens gets a simply acceptable resolving power and sharpness, becoming progressively soft towards the edges of the 24 x 36 mm negative, while a little flare appears on the whole image surface, even in the center, so albeit image quality could be defined as discreet to modern standards in terms of definition and contrast, it is usable and has a special vintage signature of its own.

Whatever it may be, the W-Nikkor.C 25 mm f/4 reaches its sweet spot between f/8 and f/11, where there´s a visible improvement in definition and contrast (still a bit low to modern standards but enough), along with an obliteration of flare to practical effects.

Slightly left front view of the W-Nikkor.C 25 mm f/4 coupled to the Leica M7. This wonderful lens features tiny and fragile aperture blades, so if needed, it should only be fixed by an experienced technician. Regarding its image quality, if yields very good results with black and white films at f/8 and f/11 and simply acceptable ones at f/4 and f/5.6, apart from suffering a lot of vignetting. The focusing tab (visible under the lens barrel) is also very nice. 
© jmse

Though always a bit handicapped by the moderate contrast it delivers, the gradual changes between tones, hues and shades are very well rendered by this lens, particularly with b & w films.

Besides, the charming W-Nikkor.C 25 mm f/4 sports a further trait : the internal helical turns inside the objective barrel, the exterior barrel being fixed meanwhile.

And the minimum focusing distance is 106 cm.

© jmse

The upshot of it is that this amazing camera / lens mixture manages to successfully blend and make operative two highly representative photographic products from different times : the Leica M7 (launched into market in 2002, one of the flagship models of the Leica M saga of 24 x 36 mm format rangefinder cameras, and whose most defining and innovative trait is the incredible consistency it attains using the aperture priority automatic metering in a wide range of light contexts) and the W-Nikkor.C 25 mm f/4 (a highly praiseworthy extreme wideangle lens for its time, whose first prototype was created in 1953, being launched into market in 1955 and stemming from the very deep knowledge, ingenuity, passion and working ability of Hideo Azuma, a great optical engineer of Nippon Kogaku and admirer of the German photographic industry, who strove upon approaching as much as possible to the optomechanical performance of the Carl Zeiss Topogon 25 mm f/4 with the very meager resources he had).

The fact that so many years after the creation of both photographic tools they keep on working seemlessly speaks volumes about the coherence of their raison d´être.

The author wishes to express his gratitude to Dr. Michael Schwartz, member of the Leica Historical Society of America, who kindly let photograph this camera and lens.

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