Archived posting to the Leica Users Group, 1998/04/10
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Using a ND filter (actually any filter, including a UV) doesn't change your DOF. The DOF is controlled by the focal length/diaphragm/circle of confusion/depth of focus factors. Not another piece of glass in the lens element chain. Thinking about the situation leads me to believe that a 360 set at 5/6 and a 180 + 2x with lens set at 2.8, will yield the same DOF. If this is wrong, I would indeed like to know why. Erwin? Jim At 07:46 AM 4/10/98 -0400, you wrote: >Optical wizards all...a question: > >Will the depth of field available with a (mythical) Leica 360/4 lens set >at 5.6 be exactly equal to the depth of field available using a Leica >180/2.8 and the 2x converter at max aperture? Or (answering my own >question) would the depth of field for the 180/2x combination result in >depth of field exactly equal to a 360/2.8 with a 2-stop neutral density >filter? > >I have the 2x Apo converter, but am thinking, for DOF reasons alone, >that I need long primes. Ouch. > >Curious in Annapolis, I remain, > >David W. Almy >