Archived posting to the Leica Users Group, 1997/11/09
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]At 00:45 09/11/97 -0600, you wrote: >At 01:44 AM 11/9/97 +0000, you wrote: > >>indoors as well as outdoors, what would have the most out-of-focus >>backgrounds and shallowest plane of focus and be most suitable, all other > >No doubt about it, the 180 f/2 apo summicron will do you what you want. :-) >Eric Welch No doubt at all, but size, weight and price exclude it from my shortlist, which has only the 80/1.4 and 180/2.8 on it at the moment. I did see an interesting article on one of the news groups a while back by David Rosen, explaining the relationship between focal length, aperture and degree of background blur given same image size of the main subject. One thing that came out of that was that the longer focal lengths include less in the background than the shorter focal lengths and therefore the backgrounds are less cluttered. What I can't remember was what the relationship between different focal lengths and apertures actually was- at some point the background blur of the 80/1.4 will be matched by a longer f2.8 lens, but how much longer? It might be a case of dropping one f stop whilst doubling the focal length, which if correct would make the 80/1.4 equivalent to a 160/2 (close to the 180/2 I notice) and a 320/2.8- this would suggest that the 80/1.4 wiould be the optimum lens for this application. Can anyone who has used both state whether the 80/1.4 has noticeably greater background blur than the 180/2.8? Joe Berenbaum