Archived posting to the Leica Users Group, 2001/06/21
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Johnny Deadman wrote: > > on 6/21/01 3:42 PM, Mark Rabiner at mark@rabiner.cncoffice.com wrote: > > >> The better the lens, the more you will notice the diffraction effects. I > >> can certainly see them at f/16 and beyond on my Elmarit 28. > >> > >> -- > >> John Brownlow > >> > > How about how many "leafs" its got? Blades to make a perfect circle. > > I don't THINK leafs have much to do with it, or that shape of the iris, > until you get right down to a pinhole. Someone will correct me if I'm wrong. > > I think it has mostly to do with the ratio of light rays that are bent by > being diffracted past the edge of the iris, to those that aren't. > > -- > John Brownlow This may be the case with enlarger lenses though. A circle with points is less good. Mark Rabiner Portland, Oregon USA http://www.rabiner.cncoffice.com/