Archived posting to the Leica Users Group, 1997/08/11

[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]

Subject: Re: 35mm vs 2 1/4, and Blind Test
From: Paul Young <pauly@sdd.hp.com>
Date: Mon, 11 Aug 1997 08:58:32 -0700 (PDT)

> 
> At test (some years ago) said: Planar 2.8/80 < 20 l/mm, Summicron (>1980): 36
> l/mm
> -Alf
> 

These figures seem low. I have been doing lens resolution tests
for another UG. Since I have these two lenses, I'll put them through
the test also and post to the LUG in a week or so. 

BTW, I use print film for resolution tests. The prints are handy
for evaluating certain aspects of a lens' performance (like
color fringing). I can also look at the neg with a high quality 
microscope (Leitz) and get resolution figures if I feel there
is any compromise in the printing process, but often I can find
the limits of lens performance on the print. Although I can't
really judge color balance and contrast from a negative well,
the pfotofinisher I use produces consistent enough results
to get a relative indication. Besides, I usually include some
standard scenic shots for reference in my test roll.

Paul.