Archived posting to the Leica Users Group, 2005/06/15[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]
I think focus shift is a myth. If the focus were to shift when stopping down, this would indicate that spherical aberration is so poorly corrected that the portion (a ring) of the lens that is active between say f/8 (the enlarging aperture)and say f/2,8, the focusing aperture, has a marked;y different focus distance than the portion (a circle) from the center to the periphery at f/2.8. If this were true, the lens would suck; it would be noticeably fuzzy at f/2.8. Herb -- Herbert Kanner email@example.com 650-326-8204 Do not meddle in the affairs of cats, for they are subtle and will pee on your computer!