Archived posting to the Leica Users Group, 1997/11/06
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Aquestion about light falloff, I noticed a different (than expected) result last night when looking at some new proof sheets. I have a new to me, actually "preowned", 35mm/2 summicron (#35x,xxx , non asp., has notches for lens hood) that I am quite happy with but on the last set of proofs there are several frames with noticable corner vingnetting. I thought of mistakes I could have made. I was using the leica 35mm lens hood and a heliopan uv filter. I do not think the hood or filter were in the way as most pictures do not have the darker corners. I thought about what might have been different and realized that I was using a slower film than usual (100 ASA) and had the lens opened up more than usual, probably at f/2 for the ones with the darkest corners. On pictures I know I was stopped down more on I do not see the effect. I have had no vingnetting with a 40mm rokkor, 50 summicron, 90 rokkor or 90 tele-elmarit at any aperature thet I have ever noticed. I also have never seen the effect (although have never really looked for it) with my two nikon wide angles (24 and 35). The light falloff appears to be about 1/2 to perhaps 1 stop. It is not as apparent on an enlargment (possibly because of the light falloff of the enlarger lens sort of cancelling out the effect? -no corner burning needed :) ). I know that light falloff occurs in large format wide angle lenses (thus the use of center spot filters on some lenses) but I don't have much experience with it occuring in smaller formats. My question is: Is the light falloff a "feature" of this lens. Do others see the same effect. Is this something the aspherical version addresses?. I know this is a very small (the reason I like it) lens and it may just be what happens when the lens elements are narrower in diameter than a lens like the 35mm nikkor. I don't think there is anything physically wrong with the lens (that I can see). Any thoughts would be appreciated. Thanks. Robert Robert H. Ardinger, Jr., M.D.