Archived posting to the Leica Users Group, 1996/04/23
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]>Thought to myself how nice it >would have been if it had f22 available instead of the min. f16 allowed on >that lens. I guess there is a limit on how accurately you can make a "small >hole", but the f16 opening seemed as if it could have been reduced by >another stop within the bounds of good mechanical practice. My guess is that beyond f/16 the gain in depth of field (ie. distance range that appears to be in sharp focus in the photo) will be limited by diffraction. I haven't done the calculations (and they will depend on what constitutes sharp focus for you as well as the enlargement size and planned viewing distance), but if we are to give Leica the benefit of the doubt they probably did do the calculations and figured they wouldn't be doing us a service by including a smaller aperture. Of course nothing is stopping you from trying the unmarked smaller aperture and testing to see if you really get a larger zone of sharp focus that way. -Charlie Charles E. Dunlap Earth Sciences Dept. University of California Santa Cruz, CA 95064