Archived posting to the Leica Users Group, 1996/04/17
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Roger, The Elpro (catalog no. 16545) for the 100mm R APO lens provides a continuous focusing range from 1:2 to 1:1.1. While the maximum aperture remains 2.8, a very slight light loss may occur due to the added glass. If it exists, it has not presented a problem nor does it require a special calculation. As a footnote, I have also employed the 100mm lens, Elpro plus one or two Macro-Adapter-Rs for images closer than 1:1. It works like a charm with a solid tripod and mirror lock-up. One Leica technical guru stated, however, that an increase in the distance between the rear lens element of an APO lens and the film plane will diminish image quality. If so, I have not seen it in terms of color vibrancy and image sharpness. You will, of course, lose one-half f-stop for each Macro-Adapter-R that is used. Bill Christensen Bill Christensen