lunes, 12 de enero de 2009

SUMMILUX-M 24 MM F/1.4 ASPH: INITIAL IMPRESSIONS ON A NEW LEICA OPTICAL SUPER TOUR DE FORCE

Text and Photos: José Manuel Serrano Esparza. LHSA


For the nth time through its history, Leica has looped the loop designing the best and smallest 24 mm f/1.4 wideangle lens ever built, whose optical performance could be simply defined like out of parameters, since the image quality it delivers remains practically the same both at full aperture f/1.4 and stopping it down, also carrying the day in regard to the maximum miniaturization of the lens (a constant search from the very beginning of Leica RF cameras in 1913), whose size and volume are actually small taking into account the huge aperture for a wideangle lens, a further factor making it highly exotic.

Its photographic applications are rather manifold, but perhaps it is in photojournalism and street photography where this sumptuous lens will excel used handheld under available light conditions without flash, however subdued they may be. And evidently, the possibility of using the f/1.4 aperture will enable the photographers to get hand and wrist a lot of ambient light pictures impossible to obtain with other not so luminous 24 mm lenses, and always without losing a whit of image quality.

Henceforth, the Summilux-M 24 mm f/1.4 ASPH will embody the world reference of ultraluminous wideangle objectives for rangefinder cameras in terms of maximum aperture and professional image quality at absolutely all diaphragms.

REASONS FOR THE DESIGN
A 24 mm wideangle lens featuring a f/1.4 top aperture means indeed tackling a great optical and mechanical challenge because of a number of reasons.

First of all, due to its short focal length, a 24 mm lens sports a remarkable depth of field even at the greatest apertures, which usually are between f/2 and f/4, depending on the brands.

This way, a 24 mm f/1.4 lens could seem oddball enough in principle, for it is a very specific fairly wide angle focal length whose missions are more or less highly clearly profiled in advance, most times looking for pictures with maximum depth of field from rather nearby distances. Examples of this usage of the 24 mm focal length are abundant in so different photographic genres as landscape, architecture, photojournalism, street photography, fashion, night photography, etc.

On the other hand, always understanding that at least on paper such wideangle lenses like the 24 mm focal length don´t need to be very luminous because of the tasks for which they are created, we´ve got the added significant factor that there is a very good Elmarit-M 24 mm f/2.8 ASPH (7 elements in 5 groups, weight of 388 g in black anodized or silver chrome finish, minimum focusing distance of 70 cm and equivalent to a 32 mm f/2.8 lens on the Leica M8 ), an extraordinary Carl Zeiss Biogon T* ZM 25 mm f/2.8 (9 elements in 7 groups, weight of 260 g, minimum focusing distance of 50 cm and equivalent to a 33 mm f/2.8 lens on the Leica M8) and a Cosina Voigtländer Color Skopar 25 mm f/4 in M mount (7 elements in 5 groups, weight of 141 g, minimum focusing distance of 90 cm and equivalent to a 33 mm f/4 lens on the Leica M8), apart from exotic jewels difficult to find and expensive rangefinder 25 mm lenses like the legendary Leica screw mount W-Nikkor C 25 mm f/4 (a symmetrically designed 4 elements in 4 groups, being greatly a wonderful copy of the German Topogon 25 mm f/4) launched into market by Nippon Kogaku in 1953 for Nikon rangefinders, which can be attached to a Leica M8 through adapter, although image quality, highly nice in terms of aesthetic beauty, can´t match the performance of the aforementioned modern Leica, Cosina Voigtländer and Zeiss ZM 24 and 25 mm wideangles in terms of resolving power, contrast, correction of aberrations and distortions and above all synergy with the 27 x 18 mm 10 megapixels Kodak KAF-10500 CCD of the Leica M8 (albeit this tiny and charming Nippon Kogaku lens goes on delivering very good optical performance on 35 mm analog M Leicas).


In my viewpoint, there could have been five main motives for the creation of this ultraluminous Summilux-M 24 mm f/1.4 development:

a) The clear dominance of the already cited and extraordinary Zeiss Biogon T* ZM 25 mm f/2.8, till now the best 24/25 mm rangefinder lens in the world regarding optical performance, featuring amazing definition and contrast across the entire image field, a tremendously painstaking mechanical accuracy with the rangefinder system, a remarkable reduction to zero of any possible blendendifferenz to avoid even the most subtle focusing shift on stopping the lens down (searching for the most accurate focus feasible, even in the shortest distances), state of-the-art antireflection coatings and virtually no distortion, together with an excelent bokeh based on its ten diaphragm blades and fairly circular aperture, with the added bonus of a first class highly durable all metal barrel.

Perhaps one of the most significant goals for Leica with the Summilux-M 24 mm f/1.4 ASPH has been to beat the extraordinary image quality of this Zeiss ZM 25 mm f/2.8 wideangle lens, something really in the frontier of the impossible, even more stretching the maximum aperture nothing less than two stops and fighting tooth and nail to accomplish it even at f/1.4! A kind of supreme optical tour de force challenge.

b) The great high sensitivity picture taking ability preserving top-notch image quality of the digital Leica M8, a gorgeous photographic tool for making handheld low and very low light photographies, including at night in the most tricky conditions (superb noiseless image quality at ISO 1250 and revealing a bit of noise at ISO 2500 resembling both the Kodak Tri-X 400 and the Ilford HP5 Plus 400), always bearing in mind that the absence of a slapping mirror in the digital rangefinder Leica M8 enables the photographer to make pictures with hand and wrist at ISO 1250 for which he´d need to use often double the sensitivity to be able to take the same photographs with any professional digital reflex camera without a tripod or monopod to prevent blurring.

Id est, to all intents and purposes, using ISO 1250 with the Leica M8 is most times equivalent to use between ISO 2000 and 2500 with a dslr pro camera in the same locations so as to be able to save the picture, and delivering a higher image quality, because of the lower ISO and the superior optical performance of the Leica M lenses (smaller and less weighty than the reflex lenses, which makes handholding much easier, avoiding any trepidation affecting sharpness) that are very pure designs manufactured without compromises of any kind and optimized for best performance at the widest apertures (specially the most up-to-date lenses featuring aspheric surfaces).

Taking into account that until now the maximum aperture available for a rangefinder 24/25 mm lens was f/2.8 (Elmarit-M 24 mm f/2.8 ASPH and Zeiss Biogon T* ZM 25 mm f/2.8), the mere possibility of using the new Summilux-M 24 mm f/1.4 ASPH (a 200% more luminous lens) on a Leica M8 is absolutely a dream come true for enthusiasts of handheld available light pictures without flash in all kinds of very dimly lit environments, keeping the genuine atmosphere of the place at the very instant of the photographic act.


c) The high level photojournalism, in which the 28 mm, 35 mm and 50 mm lenses are the most significant objectives. In this context, the most important thing is to take the picture, however poor the luminous conditions may be, and evidently, to have a Leica M8 with the Summilux-M 24 mm f/1.4 ASPH (equivalent to a 32 mm f/1.4 lens in 35 mm format) shooting handheld can make a great difference in a lot of photographic circumstances where it´s not possible to make use of a flash in order not to disturb the people photographed, to preserve the actual ambient light of the place or to avoid at all costs drawing attention and being pinpointed (specially in war photography).

And regarding handheld night photography with available light, it seems apparent that this ultraluminous Leica wideangle lens will be head over heels the world reference, and I think that at full aperture f/1.4 it will show excellent sharpness across the whole frame and exceptional field depth, together with lavish shadow detail and absence of coma on the lights.

The Summilux-M 24 mm f/1.4 ASPH will stand out above all being used as a highly luminous photographic implement able to save pictures at f/1.4 in the most exacting very low light situations, always handheld and not as a mere working maximum aperture option, but preserving a very high image quality in spite of the great wide f/1.4 f stop.

In addition to the previously quoted great advantages on making pictures under very dim conditions, if luminic levels are normal, photojournalists using the Summilux-M 24 mm f/1.4 (equivalent to a 32 mm f/1.4 on the digital Leica M8) will have the constant choice of taking great advantage of the hyperfocal technique, shooting in an exceedingly fast and intuitive way, reaching a huge percentage of valid production and avoiding to use very valuable tenths of second to focus.

I deem that compared to the also excellent Summilux-M 21 mm f/1.4 (equivalent to a 28 mm f/1.4 on the Leica M8), the Summilux-M 24 mm f/1.4 lens is even a more versatile lens on the digital M8, because its equivalent focal length of 32 mm is approximately midway between the 28 mm and the 35 mm focal lengths (two absolutely very important lenses in photojournalism domain, together with the charismatic 50 mm).


d) The creative photographers of genres like fashion, commercial pictures with great impact, glamour, etc, who can find new expressive options, getting a very selective focus, specially at the shortest distances, which enhances a great deal the out of focus rendering of the least important areas of the frame and at the same time highlights the subject photographed, something most times not within reach of the 24, 28 and 35 mm wideangle lenses, whose depth of field is generally very large even at intermediate diaphragms like f/4 and f/5.6, and sometimes at f/2.8.

The lens has in the main a very useful wide application potential, due to the combination of wideangle features and ultra high speed, which is fostered by the extremely large angles it covers and its compact dimensions. That´s why the Summilux-M 24 mm f/1.4 ASPH lens can offer a dual use: on the one hand taking advantage of its shallow depth of field at full aperture, which allows to make close focus shots detaching the person or product photographed from the background ; and on the other hand, it is always available the possibility of stopping down to medium diaphragms from which the depth of field range will be so great that all kind of landscapes will be depicted in sharp focus.

e) To create a professional wideangle lens increasing the luminosity and optical performance of the superb Summicron-M 28 mm f/2 ASPH (calculated by Michael Heiden and mechanically constructed by Holger Wiegand, a full-fledged optical feat in itself, because it was made with less size and weight than previously specified), the Summilux-M 35 mm f/1.4 ASPH and the Summilux-M 35 mm f/2 ASPH, a tremendously difficult task, because the three are unanimously considered stellar performers and the elite of the Leica-M wideangle lenses between 28 and 35 mm focal lengths (together with the also stellar Zeiss ZM Biogon T* 28 mm f/2.8 and ZM Biogon T* 35 mm f/2)

This Summicron-M 28 mm f/2 ASPH lens, a top-notch primer lens highly appreciated by world class photojournalists, has been until now the reference of Leica-M wideangles line-up between 24 and 28 mm, and despite its very wide f/2 aperture, it outperforms at all f stops, even at full diaphragm opening, the previous fourth version of the Elmarit-M 28 mm f/2.8 (a modified retrofocus design featuring 8 elements in 7 groups, with front element having a concave front surface and the rear one being a dispersing meniscus).

There´re a lot of clues suggesting that the optical performance of the new Summilux-M 24 mm f/1.4 goes a step beyond the Summicron-M 28 mm f/2 ASPH, at all diaphragms between f/2 and f/11, probably equalling if not very slightly beating at f/1.4 the Summicron-M 28 mm f/2 ASPH at full aperture, hence Leica would have pioneered a new era in the creation of superluminous wideangle lenses delivering very high image quality at f/1.4, with the steady chance for pros to attain extraordinary optical performance at f/2 which will hardly improve on stopping the lens down.


FOCAL LENGTHS APPLICATIONS ON RANGEFINDER CAMERAS
The Summilux-M 24 mm f/1.4 ASPH will have two main scopes of focal lengths as to its usage on rangefinder cameras:

1) As equivalent to a 24 x 36 format 32 mm f/1.4 lens on the digital Leica M8 (1.3 x crop factor).

Bearing in mind that both the Summicron-M 28 mm f/2 and the Elmarit-M 28 mm f/2.8 are equivalent to a 36.4 mm lens on the Leica M8, the option of the Summilux-M 24 mm f/1.4 ASPH is highly useful to have a lens midway between the 28 and 35 mm focal lengths, something of top paramount importance because of its versatility in reportage.

To practical effects, this usage of the Summilux-M 24 mm f/1.4 as a 32 mm f/1.4 lens on the digital Leica M8 will greatly mean (along with the Summilux-M 21 mm f/1.4 ASPH which is exactly equivalent to a 28 mm f/1.4 on the M8) the fulfilment of a very luminous 28 mm wideangle top quality lens dream embodied till now by the excellent Nikon AF 28 mm f/1.4D Aspherical (made between 1994 and 2006 for Nikon reflex cameras, and featuring 11 elements - one of them a precision ground aspheric- in 8 groups), delivering a top-notch image quality with outstanding sharpness and colour rendition from f/2 on and good at f/1.4, unlike the new ultraluminous German wideangle, whose optical performance at f/1.4 will be superb and only slightly inferior to the one achieved on stopping it down, which is undoubtedly a very meaningful quantum leap compared to the great and very sought after Nikon lens, and it will also be able to take out similar missions to the ones performed by a Summilux-M 35 mm f/1.4 ASPH, whose image quality will probably be a bit improved at all diaphragms including f/1.4 by the new Summilux-M 24 mm f/1.4 ASPH, undoubtedly a great achievement, because of the difference of 11º in angle coverage, which makes much more difficult and strenuous the design of a top-notch 24 mm f/1.4 lens than a 35 mm f/1.4 one.

2) Such as it is, as a 24 mm f/1.4 wideangle lens on any M mount analog 35 mm rangefinder camera like the Leicas M2, M3, M4, M4P, M5, M6, M7, MP, Voigtländers Bessa R, Bessa R2A, Bessa R3A, Bessa R4M, Konica Hexar RF, Rollei RF, Zeiss Ikon camera and all classic screw mount Leicas (through adaptor) like the Leica III, Leica IIIa, Leica IIIf red dial, Leica IIIG, etc, specially suitable for creative pros devoted to architectural photography, scenic portraiture and large coverage landscapes, and generally speaking for all kind of pictures taken at a very short range between approximately 80 cm and 4 meters in which we do wish to highlight a subject in the foreground area by means of the composition or emphasizing its traits, because the Summilux-M 24 mm f/1.4 ASPH is a great lens to fill the nearest zone with plenty of interesting elements and details. These sort of photographs boast great impact and belong to the essence of photojournalism.

In association with the best chemical colour slides (Fuji Velvia 50 and 100F, Fuji Astia 100, Fuji Provia 100F, etc) and films (Fuji Reala 100, Kodak Ektar 100, Fuji NPH 400, Fuji Xtra 800, Fuji NPZ 800, etc), the Summilux-M 24 mm f/1.4 ASPH will be able to deliver very good results handheld and extraordinary on a tripod, something which will be even fostered when using the cream of the crop of black and white chemical emulsions (Adox CMS 20, Rollei ATP-V1 32 ISO, Ilford Pan F 50, Rollei Retro 80 S, Fuji Acros 100, Kodak T-MAX 100, Ilford Delta 100, Argenti PAN-X 100, Rollei CN 200 Pro Digibase, Rollei Superpan 200, Kodak T-MAX 400 New, Ilford Delta 400 Professional, Rollei Retro 400 S, etc), where the Summilux-M 24 mm f/1.4 will reach its best, specially with the lowest sensitivity b & w quoted films between ISO 20 and ISO 100 (whose very high resolution requires to use top quality lenses along with a great mastery of the technique and skill by the photographer), an authentic treat for the lovers of the darkroom developing their own films with different chemicals, development times, temperatures and concentrations and making big enlargements on b & w photographic paper.

Besides, each b & w film features its characteristic grain possessing compositional value which can´t be emulated digitally, though Fine Art enthusiasts can greatly take advantage of hybrid work techniques, that´s to say, developing their monochrome negatives in the darkroom and digitizing them with a good film scanner, which means boundless chances for corrections and outputs, controlling the shades of gray and gradations on the screen.

Have no doubt: Together with the digital Leica M8 scope, this black and white chemical film domain between ISO 20 and ISO 100 (with their high definition and unique aesthetics, specially in big enlargements on b & w photographic paper) is the other great territory for the best performance of the redoubtable Summilux-M 24 mm f/1.4 ASPH, which shall make you rave about the obtained results.

And in spite of its great angle of view and luminosity, it is possible to use filters, because the rectangular metal lens hood accomodates series VII (24 mm) filter mounts, also being feasible to use polarizing filters size E72 (24 mm) with special filter adapters.


MECHANICAL CONSTRUCTION
The Summilux-M 24 mm f/1.4 ASPH build quality and finish are of the highest standard.

Historically, one of the most distinctive traits of the Leica M lenses has always been their out-and-out building quality and the highly painstaking attention devoted by the German photographic firm to the mechanical components of all of its objectives, integrating high precision parts into functional assemblies, with a steady search for utmost precision, something instrumental in achieving the full potential of high performance optics.

Leica lenses are famous because of their longevity and fairly stringent quality controls which bring about a tremendous precision during many decades, even with hard use under extreme conditions, and the firm has got many testing departments whose mission is to guarantee the utter quality assurance, in such a way that before being ready for production, each individual lens must undergo a very complex series of tests previous to its manufacture.

Likewise, both the individual mechanical components and the glasses are put to very hard tests.

So, Leica M lenses are made according to the highest demands and the harshests conditions, and once a lens is finished, it will undergo rather exacting tests for 75 or more criteria, something which added to the exceedingly tight tolerances kept during the making of the objectives, insures a high production uniformity.

Leica also carries out photographic tests using the lenses under cold and hot temperatures changes so as to guarantee the flawless working of the objectives after bearing -20º C to + 20º C shocks and backwards, together with an impressive shock resistance frequently in the range of 100 Gs, which greatly minimizes the risk of damage during the transportation of the rangefinder M lenses.

Another decisive side to which Leica pays top attention is the helical focusing mounts, striving for choosing the best possible noble materials, usually brass and aluminum, and besides, Leica lenses don´t feature thick layers of lubricant progressively leaking out with the elapse of time, since often focusing mount parts are adjusted one by one to each other so as to get maximum fit accuracy, which avoids to use a number of different lubricants. Hence, it´s only necessary a very thin layer of a high end lubricant exclusively developed for Leica which guarantees an even movement of the focusing mount irrespective of any extreme temperatures and extensive use by professional photographers for many decades.

Needless to say that every Leica M lens can be used by hook or by crook in all climates and continents, however harsh they may be, between 25º C below zero and 60º C, for every component is protected against corrosion, humidity and freezing.

From the scratch, there´s a very sophisticated mathematical pattern on which the individual lens elements are joined into various optical systems during the assembling phase, and this rather up-to-date system makes up for any tolerance deviation which could take place in the manufacturing stage.


And last but not least, the top quality Leica black anodizing, bright chrome plating or titanium plating of many components of the Leica M Lenses exert a decisive influence on their very long lasting showy cosmetic appearance, looking brand new for generations.

Leica have always had a straightforward penchant for manufacturing not jerry-built products featuring programmed obsolescence, but very high quality cameras and lenses since 1913.

I´m telling you, the Summilux-M 24 mm f/1.4 ASPH epitomizes all of the aforementioned very stringent multiple controls and more than narrow tolerances and is an apex of that philosophy, featuring an excellent mechanical construction in which the most advanced assembling, adjustment and centering techniques have been implemented.

On the other hand, its state-of-the-art and hugely difficult to make turned aspherical surface is of the type called ´ hot blank pressed method ´, (a complex technology sporting the benefit of enabling to manufacture aspherical lenses in a greater variety of optical glasses than the one allowed by the ground method ) and is absolutely decisive -together with the 5 anomalous partial dispersion elements- in attaining the stratospheric image quality this Leica M 24 mm wideangle will be able to deliver from f/2 on and excellent at full f/1.4 aperture, the first one in history reaching this level of optical performance, clearly beating the manual focusing Canon FD 24 mm f/1.4 S.S.C Aspherical (10 elements in 8 groups), the manual focusing Canon FD 24 mm f/1.4L (10 elements in 8 groups) for classical reflex Canon FD mount cameras , the autofocus Canon EF 24 mm f/1.4L USM first version (11 elements -one of them aspherical and another one UD- in 9 groups) and the autofocus Canon EF 24 mm f/1.4L USM second version (the latter recently appeared in September 2008 with new optical formula sporting 13 elements -two of them being low dispersion and other two UD- in 10 groups) for Canon EOS AF reflex analog and digital cameras, which had been till now the most luminous 24 mm wideangle lenses in production, all of them sporting a very high image quality (specially the 2nd version of the Canon EF 24 mm f/1.4L USM, which boasts Subwave Length Structure Coating technology minimizing ghosting and flare and very sealed against dust and rain), though the Summilux-M 24 mm f/1.4 ASPH is in another dimension of optical performance and image quality, belonging to a new era in the designing of highly luminous wideangle lenses which has just been opened since the very instant of its birth.


WEIGHT AND DIMENSIONS
Under normal circumstances, the great luminosity f/1.4 of the Summilux-M 24 mm f/1.4 ASPH should mean, at least on paper, big size and weight along with a somewhat rather cumbersome using.

But nothing related to this lens is normal, and though it isn´t evidently as small as most Leica M wideangles, in my viewpoint both its weight and dimensions have been restrained to the maximum feasible limit if we bear in mind the f/1.4 great aperture:
500 g and a length of 58.5 mm without lens hood and 75. 6 mm with it

Hence, the Summilux-M 24 mm f/1.4 ASPH handling is very good and convenient.

As to the available rangefinder 24 and 25 mm lenses in M mount, the figures of weight and dimensions are these:

- The Elmarit-M 24 mm f/2.8 ASPH features a weight of 388 g, a length of 45 mm and a largest diameter of 58 mm.

- The Elmar-M 24 mm f/3.8 has a weight of 240 g and a length of 40.6 mm without lens hood, 56.6 mm with lens hood, and a largest diameter of 53 mm.

- The Biogon T* 25 mm f/2.8 sports a weight of 260 g and a length of 53 mm without lens hood and 71 mm with it.

Evidently, the biggest and heaviest lens is the Summilux-M 24 mm f/1.4, but it isn´t less true that in spite of it, the lens is not bulky or heavy at all, specially if we pay attention to three key factors:

a) The luminosity is a 200% more than the Elmarit 24 f/2.8 and the Biogon T* 25 f/2.8 and almost a 300% more than the Elmar 25 mm f/3.4.

b) The number of elements and groups inside the Summilux-M 24 mm f/1.4 (10 elements in 8 groups) is higher and featuring better optical glasses than the Elmarit-M 24 mm f/2.8 ASPH (7 elements in 5 groups), the Elmar-M 24 mm f/3.4 (8 elements in 6 groups) and the Biogon T* 25 mm f/2.8 (9 elements in 7 groups).

c) The length of the Summilux-M 24 mm f/1.4 ASPH is 58.5 mm, id est, 17.9 mm longer than the Elmar-M 24 mm f/3.4, 13.5 mm longer than the Elmarit-M 24 mm f/2.8 ASPH and only 5.5 mm longer than the Biogon T* 25 mm f/2.8.

The optical formula of the Summilux-M 24 mm f/1.4 is overcrowded with the current worldly cream of the crop of state-of-the-art optical glasses, to wit 1 turned aspherical lens hugely difficult and expensive to make through blank-press methods and 5 elements boasting anomalous partial dipersion.

Apart from the very steep production cost and exceedingly high level of craftsmanship required to manufacture them, these six elements (specially the turned aspheric one) are heavy. That´s why the aforementioned small difference in length of the Summilux-M 24 mm f/1.4 ASPH, specially in regard to the Elmarit-M 24 mm f/2.8 ASPH and the Biogon T* 25 mm f/2.8 (both of them 200% less luminous) is a great attainment of remarkable compactness, to such an extent that it is currently the smallest 24 mm f/1.4 lens in the world.

If we add to this the fairly thorough mechanical construction of the metal lens barrel, focusing ring, superb anodizing and use of the uncompromising quality in the best noble metals chosen by Leica to make the Summilux-M 24 mm f/1.4 along with its very high level of mechanical precision, I´d dare to define as a great achievement for Leica to have been able to manufacture it under a weight of 700 g and a below 70 mm length, perhaps even more if we realize that the superb Summilux-M 35 mm f/1.4 ASPH (9 elements -one of them aspherical- in 5 groups and 53 x 46.2 mm length) has a weight of 415 g with one element less than the Summilux-M 24 mm f/1.4 also with one of them being aspherical, and without the 5 anomalous partial dispersion elements. And besides, within these parameters of top-notch quality of image delivered practically at all apertures and focusing distances, it is much more difficult to make a top-notch 24 mm f/1.4 lens (view angle of 84º ) than a 35 mm f/1.4 lens view angle of 64º), because optical aberrations tend to grow hugely not only on increasing the aperture, but also when the angle of field becomes larger.

On the other hand, and though unlike the also new Summilux-M 21 mm f/1.4 ASPH the Summilux-M 24 mm f/1.4 can be used without a separate finder, I deem advisable to attach one to the camera, because the lens invades quite a bit the view field through the finder. To this effect, Leica have also launched a very beautiful viewfinder for the Summilux-M 24 mm f/1.4 ASPH (and another one for the Summilux-M 21 mm f/1.4 ASPH).


OPTICAL PERFORMANCE AND IMAGE QUALITY
Once more, there will be two available choices, with the Summilux-M 24 mm f/1.4, both of them rendering stratospheric image quality:

a) With the digital M8.- Here, first of all it is very important to understand that unlike analog cameras in which there were three decisive factors in the creation of the image: the lens, the type of film and the processing of it, now with digital cameras things are rather different and the final image quality obtained will depend on the whole system, whose most significant factors are the lens (even more important than before and in my opinion the most decisive thing of everything), the digital sensor, the DSP, the internal firmware of the camera and often also the postprocessing.

Truth is that until now, the already existent Leica M lenses have proved to deliver a tremendously high quality of image between ISO 160 and ISO 1250 (and acceptable at ISO 2500) in great synergy with the digital rangefinders Leica M8 and Leica M8.2, something greatly enhanced by the 6 bit coding able to identify 64 different lens types, which enables the camera to achieve a remarkable specific picture optimization for each respective lens, above all regarding the correction of vignetting (the digital CCDs are much less tolerant than film with oblique light rays), a very critical factor with non retrofocus symmetrical wideangle lenses designed for rangefinder cameras, since their back lens elements go much more deeply into the camera body (the best in the world in terms of resolution and lack of distortion, because this feature enables to increase the number of lens elements to improve correction up to the boundaries of physical science) than retrofocus wideangle lenses designed for reflex cameras (which are bigger in size, heavier and bound to radically increase the backfocus distance to clear the mirror).

In my opinion, there´s a high probability that the Summilux-M 24 mm f/1.4 ASPH on the Leica M8 and its Kodak KAF-10500 CCD delivers resolution figures in the center of approximately 45 lines/mm at f/1.4, about 55 lines/mm at f/2 and around 60 lines/mm between f/2.8 and f/11.

This would mean a tremendous optical performance and image quality in terms of resolving power, sharpness and contrast,but above all an incredible evenness of optical performance at all diaphragms, and stopping down the lens from f/2 on won´t mean a significant betterment in image quality, however astounding it may seem.

There are already some extraordinary Leica M lenses featuring this trait, like the Summilux-M 50 mm f/1.4 ASPH, the Apo-Summicron-M 75 mm f/2 ASPH and the Apo-Summicron-M 90 mm f/2 ASPH, but it´s the first time in history that a 24 mm wideangle lens attains it, hence the Summilux-M 24 mm f/1.4 ASPH is currently unique among the lenses in the 24 and 28 mm range, and opens a new era in the manufacture of highly luminous extreme wideangles, together with the also new Summilux-M 21 mm f/1.4 ASPH.

But things don´t end here. There´s more.

Leica have always struggled to the death for offering their customers the minimum quality variation feasible between center and corners, and in this respect, I think that the resolution figures in the corners of the Summilux-M 24 mm f/1.4 ASPH could be approximately 40 lines/mm at f/2 and f/2.8 and 57 lines/mm at f/4, f/5.6, f/8 and f/11, perhaps not dropping below 35 lines/mm at f/1.4.

Evidently, the optical formula of the new flagship of 24 mm wideangle lenses does invite to optimism: 10 elements in 8 groups, one of the elements being the best turned aspherical lens ever made for a wideangle objetive, and other five ones boasting anomalous partial dispersion are not to be overlooked. In this case, more lens elements have resulted in achieving a significant improvement in optical performance and a further control of more parameters.

On the other hand, the Summilux-M 24 mm f/1.4 ASPH boasts an almost negligible -2.2 % distortion figure (something astounding for a 24 mm lens) not detectable in most of photographic applications.


Regarding vignetting figures, because of pure physical laws, it is impossible that such a luminous 24 mm lens can match the very low vignetting figures of 35 and 50 mm also stellar Leica-M high speed performers like the Summilux-M 35 mm f/1.4 ASPH, Summilux-50 mm f/1.4 ASPH, etc, but in any case the fall-off figures of the Summilux-M 24 mm f/1.4 ASPH connected to the Leica M8 are excellent for such a wide focal length: 1.9 diaphragm at full f/1.4 aperture and a remaining natural vignetting of 0.8 diaphtragm starting at f/2.8, so fall-off figures will be similar after stopping down the lens further.


Once again Leica proves its impressive optical prowess, because the Summilux-M 24 mm f/1.4 ASPH sports double the luminosity of the Summicron-M 28 mm f/2 (till now the best Leica M wideangle lens in the range 24-28 mm), and so the designing difficulties to beat the latter´s superb level of optical performance with the Summilux-M 24 mm f/1.4 ASPH increased in geometrical proportions, because at the same time, it is more difficult to make a top-notch 24 mm lens than a 28 mm one, though Leica has solved the outstanding conundrum with high marks, even at the closest focal distances, thanks to one group located at the rear of the optical system (between the sixth and ninth element) working as a floating element that moves independently of the rest of the mechanism and preserves the image quality also at the shortest ranges up to the minimum focusing distance of 70 cm.

Needless to say that the quoted five anomalous partial dispersion elements are utterly decisive in correcting the lateral chromatic aberrations, which prompts an exceptional correction of colour, greatly complementing the excellent corner to corner drawing from 70 cm to infinity brought about by the already cited floating elements.

When tackling night pictures, chances are that the Summilux-M 24 mm f/1.4 renders magnificent gradual changes between hues of colours in high key areas, while far points of light will be depicted crisply, lacking any flare or halo, which will bring about highly realistic photographs.

It´s also interesting to realize that there has been a 200% jump in luminosity from the previous Elmarit-M 24 mm f/2.8 ASPH lens to the new Summilux-M 24 mm f/1.4 ASPH, the former (a flagship lens and till now the best lens on earth in the range 24/25 mm together with the Zeiss Biogon T* ZM 25 mm f/2.8) being beaten by the latter in terms of optical performance and image quality, something astounding, because the Elmarit-M 24 mm f/2.8 is a world class masterpiece of optical prowess and the Zeiss Biogon T* ZM 25 mm f/2.8 keeps up with it.

On the other hand, the Summilux-M 24 mm f/1.4 ASPH will boast a Numantian resistance to contrast loss because of the effect of veiling glare, since the coatings of the optical elements and the inner building of the lens barrel are of the highest quality and level of thoroughness ever made, and I think that there´s a high probability that in spite of its very wide focal length of 24 mm and view angle of 84º it will beat the Summilux 35 mm f/1.4 ASPH in terms of flare suppression, reaching a performance in this regard comparable to the Summicron-M 35 mm f/2 ASPH, something astonishing because the latter ones feature a view angle of 64º.

It will also also exhibit at all apertures very high contrast and crisp definition of exceedingly fine detail on most of the image field, without any trace of astigmatism and field curvature, along with an utter suppression of veiling glare, harsh halos and double images surrounding point shaped light sources, with the added bonus of a noteworthy ability to capture smoothly graded variations of illumination, without forgetting an excellent flatness of field.

Regarding the very important centering and cementing, Leica have performed wonders in this lens, and it will also be instrumental in attaining the superb image quality it delivers.

Though in my opinion the Summilux-M 24 mm f/1.4 ASPH belongs to a new extraordinary generation of aspherical Leica M top primes which has just been opened together with the Summilux-M 21 mm f/1.4 ASPH, the Elmar-M 24 mm f/3.4 ASPH and the Noctilux-M 50 mm f/0.95 (giving birth to a new era in the designing of exceptional performance wideangles and standard lenses), very probably it will yield a rather fuzzy bokeh at the widest diaphragms, keeping the profiles of the subjects or motifs simultaneously with a fast vanishing of fine details into the blurred out of focus background. This is a feature usually shared by all the high quality Leica M aspherical lenses.

The Summilux-M 24 mm f/1.4 ASPH embodies a great deal the present and future of Leica M lenses designs: compact, high speed and excellent performance lenses, with no compromise at all between small size and weight and image quality rendered, something praiseworthy enough, because the maximum feasible miniaturization of the ultraluminous M lenses makes everything even more difficult.


b) With Leica M analog cameras and other rangefinders.- Here things will go the ´old´ way, id est, the binomial lens quality + type of film, together with the development of the chemical emulsion.

Used this way, coupled to an analog rangefinder M mount camera (or screw mount with adapter to M bayonet), there´s a high probability that the Summilux-M 24 mm f/1.4 ASPH reaches approximately resolution figures in the center of 60 lines/mm at f/1.4, 75 at f/2, 80 at f/2.8 and between 100 and 110 lines/mm from f/4 to f/11, together with an outstanding uniformity of performance between center and corners, an awesome optical exploit for a 24 mm lens, which is an objective in the boundary of the extreme wideangles.

Using film, distortion will be of 2.2 %, and vignetting at full aperture will reach approximately 3.2 diaphragms.

The owners of rangefinder M mount cameras will treat themselves using the best low and intermediate sensitivity colour films and slides between ISO 32 and 800 with the chance of attaining handheld great results, including gorgeous projections of slides in large sizes.

And if we speak about possibilities with the best black and white films between ISO 20 and ISO 100, the Summilux-M 24 mm f/1.4 ASPH will utterly pay off both hand and wrist and specially on a tripod, for black & white elite chemical emulsions are the ones allowing a top-notch lens reaching its maximum resolution and lines/mm, so the guessing resolution figures I gave before would be even better using b & w films like Adox CMS 20, Rollei ATP-V1 32 ISO, Ilford Pan F 50, Fuji Acros 100 (specially with specific developers), etc, always understanding that in the immense majority of cases most photographers won´t reach the 100% full performance of extraordinary highly luminous lenses like the Summilux-M 50 mm f/1.4 ASPH or this brand new Summilux-M 24 mm f/1.4 ASPH.

CONCLUSION
Both connected to a digital Leica M8 or any analog Leica M (rangefinder cameras greatly favouring the design of high quality short focal lengths), the Summilux-M 24 mm f/1.4 ASPH fosters the type of close range reportage for which the rangefinder Leica cameras are famous for as great photographic tools second to none.

This is by far the best 24 mm lens ever made, and its extraordinary optical performance and image quality it will produce at the highest apertures (making stopping down almost irrelevant in terms of improvement), together with its exceedingly thorough and robust mechanical construction, fill an ultra high speed 24 mm gap in the Leica M lineup of wideangle lenses, whose focal length of 24 mm had been represented till now exclusively by the excellent Elmarit-M 24 mm f/2.8 ASPH.

That´s to say, there has been a tremendous increase in luminosity of 2 f stops, and at the same time a betterment in image quality.

Moreover, with the Summilux-M 24 mm f/1.4 Leica stretches the series of high speed M lenses into the super wideangle range domain, increasing nothing less than 2 diaphragms of luminosity
over the excellent Elmarit-M 24 mm f/2.8 ASPH and very probably beating it in optical performance and evenness across the image field from f/2.8, where the new 24 mm f/1.4 flagship will render a really top-notch image quality, but at the same the photographer will be able to have a fully professional optical performance at f/2 (superb) and f/1.4 (very good), both in center and corners, as well as opening new composition choices (specially with available light shots) on getting a previously not possible reduction of the depth of field in synergy with large angles of view.

Henceforth, the Summilux-M 24 mm f/1.4 ASPH will be the new world flagship in this focal length, followed by the magnificent runner-ups Carl Zeiss Biogon T* 25 mm f/2.8 and Elmarit-M 24 mm f/2.8 ASPH.



TECHNICAL DATA

Model: Summilux-M 24 mm f/1.4 ASPH
Real Focal Length: 24.3 mm
Position of entrance pupil: 19.2 mm (related to the first lens surface in light direction)
Number of Lenses and Groups: 10 elements in 8 groups.
Weight: 500 g.
Maximum diaphragm aperture: f/1.4
Minimum diaphragm aperture: f/16
Length: 58.5 mm without lens hood and 75.6 mm with it.
Largest diameter: 61 mm.
Distance Setting Scales: Combined meter / feet graduation
Bayonet: Leica M quick change bayonet with 6 bit lens identification bar code for digital M models.
Filter Size: Possibility of using size E72 (24 mm) polarizing filters by means of special adapter.
Number of diaphragm blades:
Smallest Object Field: 609 x 914 mm
Minimum Focusing Distance: 70 cm
Largest reproduction ratio: 1:25
Apertures settings function: Half values available, with click stops, manual diaphragm.
Angle of view: diagonal 84º, horizontal 74º and vertical 53º.
Lens Hood: Separate, patented rectangular metal one, screw-on type.
Filter Mount: Series filter VII (24 mm) in lens hood.