Leica APO-TELYT-R инструкция обслуживания

Leica R-Lenses Sept ember 2003 Chapt er 3: 1 80 mm and 280 mm lenses __ LEICA APO-ELMARIT-R 1 80 mm f/2.8 __ LEICA APO-TEL Y T -R 280 mm f/4 b y E rw in P u t s[...]

Chapt er 3 Leica R-Lenses 1 T elephot o lenses hav e a long tradition at Leica. The first 20 cm f/4.5 T elyt lens was introduced as long ago as 1 935 for the Leica rangefinder camera. An additional mirror reflex housing was required for the accurate determination of t he field of view and the focus. This 200 mm lens was designed for landscape work,[...]

Chapt er 3 Leica R-Lenses 2 In 1 975 Leitz Canada designers computed t he 1 80 mm f/3.4 Apo-T elyt-R lens for scientific purposes that required a very high information content. It is a seven-element syst em with four groups, corrected for the infrared region and it perfor ms best at infinity. At the same time Canon introduced a new 300 mm f/2.8 len[...]

Chapt er 3 Leica R-Lenses 3 In 1 993 the 280 mm f/4 Apo-T elyt-R was introduced. P er for- mance was improved, especially in the out er zones; the weight was reduced to 1 8 75 grams (66. 1 ounces) and t he price ratio of 4.8:1 was much better . In terms of per formance, both new lenses, t he 1 80 mm f/2.8 Apo-Elmarit-R and t he 280 mm f/4 Apo-T ely[...]

Chapt er 3 Leica R-Lenses 4 With these considerations it is possible to create and define the image effects that y ou want. If the main subject is encircled by objects in the fore- and bak- kground, you can visually emphasize t he relationship betw een the subjects and even make it appear as threatening, as is the case with cars that seem t o colli[...]

Chapt er 3 Leica R-Lenses 5 Atmospheric turbulence and heat wa ves can destro y the image quality at t hese large magnifications and one needs a skylight filter with color film and a medium orang e filter with black -and- white film. The discussion often arises as to whether a lens can be t oo sharp, a question t hat is certainly relevant for both [...]

Chapt er 3 Leica R-Lenses 6 Flare and secondary images are absent and specular highlights in the blazing sun are free from halo effects. Vignetting may be visible under critical circumstances (wide open), but it is eliminated at f/5.6. Distortion amounts to 1% in the comers and may be visible when one pho tographs geome tric figures (architectural [...]

Chapt er 3 Leica R-Lenses 7 The diverging cur ves at 40 Lp/mm for sagittal and tangential lines is of no relevance in practical phot ography . This reduction in contrast can only be computed; it is not visible in real life. This behavior indicates that the lens earns highest scores for color correction. The ‘ APO’ designation is well deser ved.[...]

Chapt er 3 Leica R-Lenses 8 Even so, the optical quality of the 280 mm lens is higher . Here we can detect the limit of the MTF graphs when w e restrict our- selves t o 40 Lp/mm as the highest frequency. There are sound arguments for t his limit, but when dealing with v er y high perfor- mance lenses, t he information may no t be as w e want it to [...]

Chapt er 3 Leica R-Lenses 9 Y ou will have t o find subjects that have e xtremely fine details t o start with, and then you must tak e pictures at quite a large distance, because y ou need a high value of negativ e magnifica- tion, and t hen you must enlarge the tiny negative to big propor- tions. This places the imaging chain under heavy strain. F[...]

Chapt er 3 Leica R-Lenses 10 __ Summar y In the roaring twenties there was a 540 SSK Mercedes Benz sports car with a turbo-charg ed engine. The turbo charg er could only be used for a few minutes, other- wise it w ould overheat the engine. But the driving e xperience was breathtakingly exilarating. Both the 1 80 mm f/2.8 Apo-Elmarit-R and t he 280 [...]