Re: Leitz 35mm f1.4 vs. Nikkor 35mm f1.4 (kinda..;-) - rec.photo.misc #42230

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

In article <4i1n3j$2ai@ampersand.jpl.nasa.gov>, Don Farra <Donald.D.Farra@jpl.nasa.gov> writes:
|> In article <4hptmn$hh@newsstand.cit.cornell.edu> Bob Neuman,
|> rpn1@cornell.edu writes:
|> >I recently had a chance to check out a Leitz Rangefinder 
|> >Double Aspheric Horribly Expensive ($3800 when new) 35mm f1.4 
|> >lens, courtesy of Nick Silva (who kindly shot the tests to order 
|> >and supplied the film to me). I shot similar test film (B & W and
|> >color) using a Nikkor 35mm f1.4 to attempt a comparison. Though the 
|> >Leitz lens remained in California and my 35mm f1.4 Nikkor remained 
|> >in New York, I have reasonable confidence that the results of this 
|> >long-distance comparison are reasonably valid. So, here is what I 
|> >found:
|> 
|> 
|> 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.
|> 
|> 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.   I will be shooting two cameras side by side on tripods
|> and at the same time to remove the effects of lighting changes, both
|> manually set focus and exposure.  At half way point I will rewind the
|> film in each camera and switch the rolls between the cameras and
|> repeating the tests to remove film and processing variances.  The test
|> targets will be three dimensional (high contrast as well as low contrast)
|> and fill 100% of the viewing area, in other words no empty sky in the
|> corners.  I plan to shoot both professional and off the shelf films.  At
|> this time I am running a series of tests on various print, slide and B&W
|> films to determine which will be used in the evaluation and to verify the
|> evaluation process.
|> 
|> The last part of the testing process seems to be the hardest.  How to
|> compare two test results using a side by side comparison using the memory
|> of person viewing the results as the final means of evaluation?  For
|> example I were to give you a page of slides taken from a Leica and Nikon
|> and had you compare them with a loupe you could only examine one at a
|> time.  The same holds true for prints, with one exception with prints you
|> could compare the corners by overlapping and offsetting the samples
|> allowing only the like corners to be viewed at the same time.  But to get
|> the prints both negatives/slides have been effected by the printing
|> process, lenses of the enlarger etc.  In either case the examination by
|> the person viewing the samples can bias results by his or hers
|> opinion/experience, or physical limtiations (color blindness, eye
|> distortions, etc.).
|> 
|> 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