Archived posting to the Leica Users Group, 1997/10/01
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]At 10:29 AM 10/1/97 -0400, Barney wrote: > > >Barney mis-spoke himself. I do believe I meand Summar, a pre-world war >II lens with f-stops which ran from 2 - 12 (?). There are two f/stop ranges. The one we are accustomed to today is the 'International Scale' adopted by Zeiss at the turn of the century after the Rudolph aperture range came a cropper. This scale runs: 1-1.4-2-2.8-4-5.6-8-11-16 und so weiter, each aperture being the double of the second one before it. The other is the Stoltz scale, alias the 'European' scale popularized by Leitz. Here, the numbers run: 1.1-1.5-2.2-3-4.5-6-9-12-18 and so forth. Both scales are based on squares and square roots; they are one-third stop apart from each other. The problem with using a Stolz-marked lens in today's universe is that the f/stops on the lens and the f/stops on a modern meter aren't hooked up. (I get around this by using a Weston 715 ... ) Marc msmall@roanoke.infi.net FAX: +540/343-7315 Cha robh bas fir gun ghras fir!