Re: Leitz 35mm f1.4 vs. Nikkor 35mm f1.4 (kinda..;-) - rec.photo.misc #42241

[Wolfgang Sachse <sachse@msc.cornell.edu>]

In article <4i2915$rso@newsstand.cit.cornell.edu>, rpn1@cornell.edu (Bob Neuman) writes:
|> In article <4i1n3j$2ai@ampersand.jpl.nasa.gov>, 
|> Donald.D.Farra@jpl.nasa.gov says...
|> 
|> >If I wanted to run the same comparison test what would I have to do?  
|> >The reason I asked is it appears the set of test pictures were taken at
|> >different times and locations.  Also your method of comparison was not
|> >clear, visual or measured by test patterns.
|> 
|> See answer to Gary Toop's post, above for the beginnings of some of the 
|> answers to your questions. (It has been months, but that lens checking 
|> article IS being slowly worked on....)
|> 
|> >I am currently planning on running a series of comparison tests on the
|> >Leica 35/1.4 asph to Canon and Nikon lenses both prime and zooms of 
|> >equal focal lenght. [much deleted]
|> 
|> Good luck! I would simplify your technique/materials - you will still 
|> see differences with even the simplest methods, and with any film.
|> (I have it down to 6 frames for checking a familiar prime lens for
|> construction defects and center-corner performance at relevant 
|> apertures - though it takes more to check an unfamiliar lens or a zoom.)
|>  
|> >My testing goals are simple:  determine the attributes of a particular
|> >lens with a fixed set of film & lighting conditions and make the tests
|> >repeatable such that anyone given the same equipment can repeat the 
|> >tests and come to the same conclusions.   The problem is the closer I 
|> >get to removing the human component from the evaluation process the 
|> >less likely the test will be repeatable by anyone using the same 
|> >camera equipment.
|> >Any suggestions?  Please post them.
|> >Don
|> 
|> Lots, but that would mean I finished the article! ;-) In designing 
|> tests, I would suggest remembering that lenses vary in performance 
|> with distance at least slightly (some, a lot!), flat targets are
|> nearly impossible to focus accurately, almost any film will work
|> (contrary to popular opinion), some wide-angles will show differences
|> in corner performance with color vs. B & W film, some lenses have 
|> field curvature, and most (good) lenses vary most in quality at the 
|> widest apertures and at the edges/corners. That's after eliminating 
|> the lenses that are unacceptable due to flare, cost, size, weight, 
|> distortion, condition, or any other characteristic that is bothersome
|> to you.
|> Hope This Helps
|>