HIDDEN GEMS
With the creation of the Leica SL digital system in 2015 and the myriad of lens adapters, the Leica R lenses began a rebirth. As Leica R film camera bodies became harder to get repaired, the SL system with a Leica R-Adapter L allowed the use of some great analog-based glass. In the next few articles, I will explore some of the Leica R lenses, their history and their ability to make high-quality images even today. I still use Leica R film cameras and the Leica SL digital series, so I’ll include images from both systems. At the end of this article, I’ll share some of the lenses that this series will encompass.
If you have not used the Leica R system before, you might be wondering why I am calling the increasingly popular Leica SL system a “digital” system. The answer is simple. In 1964 Leica created the company’s first single lens reflex system and the 1968 model was aptly named the Leicaflex SL. Since I am discussing lenses, when I refer to the Leica SL, I am referring to the new mirrorless digital system and not the original film SLR.
Unlike the Leica M or Leica S lenses, Leica R lenses can be divided into two main categories: zoom lenses and fixed focal lengths. The history of the fixed focal lengths in the Leica R series is broad and deeply rooted in the development of Leica M lenses. For example, the Leica Summicron-R 50mm version II is virtually the same as the Leica Summicron-M version IV. Leica R zoom lenses have a more complicated history.
For many camera manufacturers, zoom lenses were first made for convenience. They started with multiple fixed focal lengths (think of the Leica M MATE 28-50-35). In addition, the first zooms had very small f-stops (f/4, f/5.6) to keep aberrations to a manageable level. Later, advances in glass types and the processes for manufacturing aspherical elements provided the ability for zoom lens construction that rivaled some fixed focus lenses. Ingrained in the Leica culture, Leica began manufacturing zoom lenses when they could ensure their high standard could be met. This is why Leica arrived later in the zoom market. For example, the Leica Vario-APO-Elmarit-R 70-180mm f/2.8 weighs 1,870 grams and uses an E77 filter size providing very high contrast at full aperture. Erwin Puts noted that using this 1995 zoom lens in the 80mm to 110mm range at least equals the contrast and edge sharpness of the Leica APO-Macro-Elmarit-R 100mm f/2.8 macro lens, which is very similar to the current Leica Macro-Elmar-M 90mm f/4 lens. This quality is impressive for a 27-year-old lens and the same cannot be said of many 1990’s era zoom lenses from other manufacturers.
Leica R lenses have a complicated mounting system consisting of 1-cam, 2-cam, 3-cam, 3rd-cam only, and ROM lenses. I won’t go into all the details of the various Leica R cam systems as plenty of information exists on the internet. However, note that because the cam system is complex, the Leica R lenses with 1- and 2-cams are typically not compatible with later Leica R bodies and Leica R to SL adapters. In part, this is due to the ROM reader which replaces an area previously holding a cam. My favored Leica R lenses have the ROM either as released or retrofitted for a specific reason. The R to L adapter includes contacts for the ROM lenses and transfers both focal length and aperture values to the EXIF in the final digital image. This is valuable for digital catalogs when later searching or filtering, not to mention some of the metering modes in the Leica R8 and R9 series. The Leica R8 / R9 bodies have a complex multi-metering system that can take into account the vignetting of the Leica R lenses with ROM contacts and is one of the best I’ve seen for film cameras including the Nikon F3.
If you are still questioning the quality of a zoom lens from Leica or using an older film-based lens on a newer digital system, then consider some of the Leica R development history. Leica R offerings started as wide as 15mm and extended to the 800mm arena. There are some one-of-a-kind Leica R lenses outside this range, but we mere mortals only have access to the wide variety of focal lengths in the standard catalog. More interesting are the partnerships over the years between Leica and Minolta, Schneider and Kyocera. There are fingerprints of these design and manufacturing partners in some Leica R lenses, and no doubt have a lot to do with the L-Mount consortium that Leica has developed with the modern SL system.
A single lens reflex system has different challenges than a compact range-finder. Where the Leica M lenses are designed for high quality in a small package, the same limitation did not exist for the larger SLR systems. However, the impact of the mirror between the lens and the film does cause some needed adjustments. The distance between the lens mount and the film plane is 47mm. This means a 21mm lens for the Leica R system cannot be made the same way as one for the Leica M system where a lens can protrude right up to the shutter (and in fact, some have!). Instead, the Leica R system is forced to use retrofocus lens designs so that the mirror has enough room to swing. The only other choice is to raise the mirror and lock it in the up position to fit the lens, but that negates the ability to focus, which is the point of an SLR system. The idea of a retrofocus lens was not new, but it did cause the lens to require more elements and be of a larger design. This can be shown by putting the Leica Elmarit-R 19mm lens (60mm long) beside the Leica APO-Summicron-R 90mm lens (70mm long). This shows how the 19mm lens had to be larger to enable proper use with the SLR mirror and yet this super wide-angle lens is superb and hard to find as a result.
Similar to the Leica M lenses, research and development by Leica provided increasingly better image capabilities. Negative lenses were used as the front element, which led to some incredible optical improvements over time. The idea of floating elements increased the complexity of the lens designs but provided a better solution for close focusing at wider apertures. Lower vignetting was one advantage of the Leica R retrofocus designs over the Leica M lenses. While certainly still present, it could be more easily reduced. With the exception of a few zoom lenses, these characteristics apply mostly to the fixed lenses in the Leica R system. Also of interest is the fact that the mirrorless system of the Lecia SL has a short back focal length, similar to the Leica M system. This allows less use of retrofocus designs in the Leica SL system and a more compact design that would otherwise be necessary if it was not mirrorless.
There are lengthy writings on lens aberrations, and Erwin Puts is well known for providing such knowledge to the general public. While some of his writing is better understood by those that study optics as a career, there is also much information that can be understood by the interested but casual user. The following discussions I have gleaned from Mr. Puts’ writings specifically about the Leica R lenses and attribute the information to his works.
There are many aberrations that Leica optical designers combat before producing a lens used by the Leica community. I believe the most noticeable aberrations are based on the corners of lenses including both contrast and coma, as well as the differences in focusing both the tangential and saggitarial light rays. I will not try to dissect these terms, but rather talk in a simpler language. Suffice it to say that reading Mr. Puts’ work will allow an in-depth study of the science.
It is a fact that increasing the diameter of a lens to create a wider f/stop or increasing the focal length of a lens for higher magnifications causes an increase in chromatic and other aberrations. Corrections to these aberrations are not inexpensive, but available to lens designers of the appropriate aptitude. Glass with anomalous dispersion can lessen these types of aberrations, but is very expensive and harder to work with. Yet, the glass type is only one leg of the design. Ignoring the movement of light through the system, another important aspect is the required manufacturing tolerance.
The ability to consistently make a lens that retains the tolerance from the point of manufacture to many years in the future is important for a high-quality lens. Leica has succeeded in doing this as part of their culture and is evidenced by the use of 1950’s Leica M lenses on today’s film and digital cameras to still produce outstanding imagery. The roots of this success come from the willingness of Lecia to restrict focal lengths and apertures compared to some of the competition. Think about the current Leica Vario-Elmarit-SL 24-70mm f/2.8 lens which has a reduced range compared to the Leica Vario-Elmarit-SL 24-90mm f/2.8-f/4.0 lens. This choice had to do with lens diameter and quality in the total zoom range. In reality, I prefer a lens that performs throughout it’s range admirably, rather than a lens I cannot use in certain situations because the quality is not as good. It leaves me free to be creative without worrying about the resulting image quality. Erwin Puts said this about the quality of the Leica R lenses in 2003:
“I could convince myself of the longevity and sustained accuracy over many years when I was able to test and check several scores of older lenses, often very heavy used. Every lens, even the most worn out ones, were within the originally specified tolerances and there was not a sign of decentering, one of the earliest signs of degraded performance. The optical performance was as expected from a new lens just out of the box.”
At the time the Leica R system was being developed, autofocus cameras were not yet in the picture. Mr. Puts reminds us that an auto-focus system inherently “smooths out the small errors in mechanical accuracy.” The long life and continued use today of Leica R lenses is due not only to the quality of the glass and lens computations, but due to the tight tolerances of construction embedded in the Leica company’s DNA.
The other correction tool employed by Leica is the use of aspherical surfaces. Some famous Leica M lenses, including the Noctilux-M 50mm f/1.2 lens and the Summilux-M 35mm f/1.4 Aspherical lens, used hand ground and polished aspherical surfaces. As technology enabled more consistent and cost effective manufacture of aspherical lenses that were within required tolerances, lens designs added aspheres to the computations.
This discussion is relevant because some of the later Leica R lens designs used all these abilities to produce lenses that still have good contrast in details greater than 40 line pairs per mm, which is no small feat! Additionally, this provides an understanding of the performance expectations of some of the version 1 Leica R lenses. For example, the Leica APOSummicron- R 90mm f/2 has the same outstanding imagery as the Leica M model, and the older Leica APO-Elmarit-R 180mm f/2.8 resolves incredibly well at 100 line pairs per mm providing detail many sensors and films cannot capture!
From the perspective of the Leica R fixed focal length lenses, understanding how the lens will draw the light on the Leica SL sensor is much easier. The zoom lenses require a little more discussion.
The history of zoom lenses in the late 20th century is fraught with sub-par results. This tainted many professional photographers who refused their use in early development by the large camera companies. Instead, the zoom lens was an inexpensive way for an amateur to obtain multiple focal lengths. This has a lot to do with the inherent optical problems that are unique to zoom lenses. Leave it to a company such as Leica to overcome the limitations while providing extraordinary zoom lenses.
The simplicity of a zoom lens is interesting. Mr. Puts eloquently tells us that a zoom lens really has only two requirements: (1) the focal length must be continuously variable and (2) the distance setting or focus position must not change when the focal length changes. Only two lenses are needed to create a zoom lens; one lens is used for each requirement. One only need look at the complex Leica SL zooms, such as the 90-280mm zoom to see that many more than two lenses are used. Yet, Leica also designed the lens to have two very small and light lenses accomplish the focusing. The remainder of the system is used to change the focal length and correct aberrations.
While this may sound like an easy process, there is still more to the quality equation. Just like the prime lenses, manufacturing tolerances must still be kept small and consistent. In a zoom lens the group of lenses to change the focal length generally move in a different manner and distance than the focusing lens group. While this can be compensated in an electronic lens, manual focus lenses must accomplish this without the aid of computer chips and motors. One of the most mechanically complex lenses ever made by Leica was the Medium Angle Tri-Elmar-M (MATE) 28-50-35mm lens. Not only did the lenses have to properly move in tandem, but a mechanical connection to the rangefinder CAM system had to move the viewfinder screens adding another non-linear movement to the system. Leica’s dedication to producing high quality, consistent tight tolerance lenses provided zooms that were of such optical quality the professionals used them without reservation.
Many of the Leica R lenses were made in the 1970’s through the 1990’s. Th is makes those lens designs between 30 and 50 years old. Yet, after a CLA to clean, lubricate and adjust the lens, they essentially perform as they did new out of the box. After adding the high optical quality and strong aberration correction into a mechanical system that does not require power, another complete lens system is available for the Leica SL.
I am not comparing image quality between the two systems because they are too different. The Leica SL Summicrons are another leap forward in optical results. However, that does not prevent the Leica R lenses from producing outstanding imagery alongside the native SL lenses. Add the fact that the Leica R lenses are meant to be looked through when composing an image, unlike electronic viewfinder systems, and the distortion and color representation is what-you-see-is-what you-get. I personally love using the medium format Leica S system because I can look through the optical viewfinder. The same joy comes from the use of the Leica R lens system.
All of the images in this article are from Leica R lenses and the Leica SL. In the remainder of this series, I will review some of the Leica R lenses I have acquired over time and show more images from both the Leica R film cameras and the Leica SL digital cameras. Th ese lenses include fi xed focus Leica R lenses in the range of the Leica Elmarit-R 28mm f/2.8 version 1 through the Leica APO-Elmarit-R 280mm f/2.8 lens. I will include lenses such as the Leica Summilux-R 80mm f/1.4 and the rather unique Leica Super-Angulon-R 28mm f/2.8 perspective correction lens (PC). It will also include zoom lenses like the Leica Vario-Elmar-R 21-35mm f/3.5-4 ASPH, and the Leica APO-Vario-Elmarit-R 70-180mm f/2.8 as well as the very compact Leica Vario-Elmar-R 80-200mm f/4 and others. I will talk about each lens and my experience in using them with sample images in my every-day use. The intention is not to recreate a scientific analysis of the MTF charts, but let you see how the lenses produce images using today’s modern Leica cameras.
