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Leica R-Lenses
by Erwin Puts
September 2003
Chapter 3: 180 mm and 280 mm lenses
__ LEICA APO-ELMARIT-R 180 mm f/2.8
__ LEICA APO-TELYT-R 280 mm f/4
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Leica R-Lenses 1 Chapter 3 Telephoto lenses have a long tradition at Leica. The first 20 cm spectrum. 'Secondary' may also be read as 'residual chromatic f/4.5 Telyt lens was introduced as long ago as 1935 for the errors'. Leica rangefinder camera. An additional mirror reflex housing was required for the accurate determination of the field of view A 180 mm telephoto lens has a magnification factor of 3.6x and the focus. This 200 mm lens was designed for landscape compared to the standard lens a
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Leica R-Lenses 2 Chapter 3 __ LEICA APO-ELMARIT-R 180 mm f/2.8 In 1975 Leitz Canada designers computed the 180 mm f/3.4 markable. In addition, the ergonomics were no longer state-of- Apo-Telyt-R lens for scientific purposes that required a very the-art as more and more companies introduced internal focu- high information content. It is a seven-element system with four sing. groups, corrected for the infrared region and it performs best at infinity. At the same time Canon introduced a new 300 mm
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Leica R-Lenses 3 Chapter 3 __ LEICA APO-TELYT-R 280 mm f/4 In 1993 the 280 mm f/4 Apo-Telyt-R was introduced. Perfor- We can explain this with a small experiment: mance was improved, especially in the outer zones; the weight was reduced to 1875 grams (66.1 ounces) and the price ratio of Let us photograph two objects of the same size that are located 4.8:1 was much better. one meter (3.28 feet) from each other at a distance from one meter (3.28 feet) from the first object. In terms of performan
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Leica R-Lenses 4 Chapter 3 With these considerations it is possible to create and define the these distances there is a reduction of 1.8x in the luminance of image effects that you want. the negative. The automatic exposure programs of Leica R If the main subject is encircled by objects in the fore- and bak- cameras compensate for this effect, but when you make a kground, you can visually emphasize the relationship between manual exposure, it is wise to take this into account. The occa- the subj
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Leica R-Lenses 5 Chapter 3 Atmospheric turbulence and heat waves can destroy the image For the first time, chromatic aberrations (color fringes) could quality at these large magnifications and one needs a skylight be reduced to negligible amounts. Multi-layer coating was used filter with color film and a medium orange filter with black-and- sparingly, as these layers often create more problems than they white film. solve. Especially with strongly curved surfaces and with glasses with high refrac
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Leica R-Lenses 6 Chapter 3 Flare and secondary images are absent and specular highlights Aperture Stop 2.8 [%] in the blazing sun are free from halo effects. 100 1 Vignetting may be visible under critical circumstances (wide open), but it is eliminated at f/5.6. 80 60 [%] 100 40 8.0 80 5.6 2.8 20 60 0 40 0 5 10 15 20 Y'[mm] 20 0 0 5 10 15 20 Aperture Stop 5.6 [%] Y'[mm] 100 80 Distortion amounts to 1% in the comers and may be visible when one photographs geometric figures (architectural details)
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Leica R-Lenses 7 Chapter 3 The diverging curves at 40 Lp/mm for sagittal and tangential [%] 100 lines is of no relevance in practical photography. This reduction in contrast can only be computed; it is not visible in real life. 8.0 This behavior indicates that the lens earns highest scores for 80 5.6 color correction. The ‘APO’ designation is well deserved. We 4.0 should explain this once again: there is no universally accepted 60 definition for apochromatic correction. When the secondary spectr
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Leica R-Lenses 8 Chapter 3 Even so, the optical quality of the 280 mm lens is higher. Here Aperture Stop 4.0 [%] we can detect the limit of the MTF graphs when we restrict our- 100 selves to 40 Lp/mm as the highest frequency. There are sound arguments for this limit, but when dealing with very high perfor- 80 mance lenses, the information may not be as we want it to be. The 280 mm f/4 Apo-Telyt-R lens is one of the every few lenses that is truly diffraction-limited. This means that the optical
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Leica R-Lenses 9 Chapter 3 You will have to find subjects that have extremely fine details to from sandbags to bricks attached to the tripod in order to redu- start with, and then you must take pictures at quite a large ce vibrations. I used weights placed on the body and on the distance, because you need a high value of negative magnifica- front part of the lens in order to eliminate the tremors. tion, and then you must enlarge the tiny negative to big propor- This may sound very elaborate. It
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Leica R-Lenses 10 Chapter 3 __ Summary In the roaring twenties there was a 540 SSK Mercedes Benz sports car with a turbo-charged engine. The turbo charger could only be used for a few minutes, other- wise it would overheat the engine. But the driving experience was breathtakingly exilarating. Both the 180 mm f/2.8 Apo-Elmarit-R and the 280 mm f/4 Apo-Telyt-R Leica lenses offer superior image quality plus that special turbo-feeling and sensation, not for just a few minutes, but always and everyw
