Chip Louie schrieb: > > Hi, > > Was just wondering something. I recently suggested that someone with a EF > 28-105USM and a vignette problem try testing wide open and stopping down > until the problem went away to see if the problem was the lens or the > filter. Henry P. said that lenses that vignette will be at their best when > wide open and get worse as they are stopped down. > > This is just wrong in my experience and there was a long string of trying to > explain the whys and wherefores by many others. I just watched as it got > silly and must have missed the end of it. The recent mention of the French > magazine CD and their test results on vignette refreshed my memory and I > wondered if after all of Henry's insistence that he was correct if he ever > said he was mistaken or if everyone else just gave up? >
I think both cases really exist. But you are not likely to buy a lens that vignettes in a way that gets worse when stopped down, except when used with a filter or other accessories. I once ran across such a case, when I tried out several lenses reversed in front of a 200/2.8L for macro use beyond 1:1. One of the combos, I'm not sure if it was with the 24/2.8 or the 20/2.8, looked quite acceptable through the viewfinder at first. But when I stopped down, all that was left was a circle in the center, the rest of the image went dark. I never had this with a single lens yet. Well, maybe a circular fisheye ;-) The 200/2.8 + 50/1.4 combo worked quite acceptable BTW. The "normal" case is the other one, that gets better when you stop down. Thomas Bantel * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
