Archived posting to the Leica Users Group, 2003/01/14
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]On Tuesday, January 14, 2003, at 06:49 PM, Austin Franklin wrote: > The plane of focus is an arc with the "anchor" point at the center of > the > film plane, and the radius the distance to the subject. As long as > you KNOW > that and use that to focus, there is NO changing of focus to > accommodate > this. actually that is not true, Austin. The plane of focus is indeed generally a plane, or close to it. (What you are describing is not an arc but a hemisphere). The reason for this is that the distance from the lens nodal point to the edge of the frame is further than the distance from the lens nodal point to the center of the frame. Therefore the lens is focussed further from the lens nodal point at the edges than it is at the center. JB - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html