Archived posting to the Leica Users Group, 1999/08/30
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]At 10:25 AM 8/30/1999 -0000, Doug Richardson wrote: > >One reason I opted to use reversal film was that I wanted to check for >vignetting. Marx James Small had written in an earlier posting that >"As is endemic to the Topogon breed, it is a bit slow and suffers from >about a one to one-and-a-half stop drop at the corners." Looking at >the sky in the corners of the image I can see no reduction in >brightness. I seem to recall Marc saying that the Russar had ben >returned to production in the early 1990s. Given the absence of >visible darkening in the corners of the frame, I wonder if 1990s >production is with a recomputed version. Have other Russar users >noticed vignetting, and if so what date is your lens? > I have some conflicting evidence on the heritage of this lens. Most of my sources describe it as a Topogon clone. However, Wright and Wilkinson, in their A LENS COLLECTOR'S VADE MECUM, describe it in detail as derived from the LF Russar lens, an entirely different computation. I am aware of the conflict in authority, but I've not had time to pull mine out and see if I can lock in the point without disassembling the lens. I do know that mine, and all the others I have used, vignette a bit. The lens MAY have been recomputed, or this, conceivably, could be an artifact of multi-coating if the vignetting is caused by internal reflections. Mine is not multi-coated, dating from '74. Marc msmall@roanoke.infi.net FAX: +540/343-7315 Cha robh bas fir gun ghras fir!