Archived posting to the Leica Users Group, 2004/06/25
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]On 6/25/04 8:20 PM, "James Harrison" <leicajh@earthlink.net> wrote: > > What is the longest focal lenght M lens that is usable with the SF 20? > Thanks in advance.. jh > It's the widest focal length that is limited by a flash unless you put on additional diffusion to that flash or bounce it. - Not the longest focal length. You could put a 1000mm on with a Viso if it could focus close enough to reach the flashes range. In other words if the flash could only reach OUT to 10 feet and the very long lens could not go closer IN than 12 which is not abnormal then you cant use that flash with that lens. And that 2 ft zone in which neither the flash nor the lens reached would be practically nasty; image wise. :) ...unless you have a thing which do exist to concentrate the flash bean into a narrower beam which would then reach further. Thus optimized more so for tele lenes. Some work with Fresnel lens. Invented by Harvey Fresnel. :) http://hyperphysics.phy-astr.gsu.edu/hbase/geoopt/fresnellens.html Mark Rabiner Photography Portland Oregon http://rabinergroup.com/