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Re: [Rollei] Coating Flaws in E Series

If the problem is only on the front surface of the front element, I would
suspect environmental damages rather than manufacturing problems. That being
said, I suppose it is possible the coating Schneider used was susceptible to
a particular form of environmental damage - fungus, moisture, heat??

Early Zeiss coatings on the 2.8 lenses were quite bad as well - very soft. I
have seen quite a few lenses where there is no coating left - completely
rubbed off. The front coating on the Zeiss 2.8 Planar should be a yellow
colour and these were reflecting true colour without the yellow tinge. Inner
elements of the same lens were obviously coated. Other early Zeiss 2.8
Planars I've seen had partial amounts of the front element coating left. It
seems that Zeiss did something to the coating after a few years because
later yellow tinged Planars seem fine. 


  I've seen this a number of times on lenses stored where there was a lot
of moisture. It may be the effect of fungus but I suspect it may be
something else. 
  Most coatings are Magnesium Flouride, a fairly hard and resistant
material. I don't know specifically what attacks it but have seen enough
lenses with damaged coatings, or damage which is much deeper than the
coating, to think it may be sensititve to moisture or the exudations of
  BTW, I also remember a runor that Schneider had coating problems in the
mid 1950s. My 2.8E shows some coating flaws on the outer surface but
neither of my Xenars do nor does a Componon enlarging lens from about the
same period. Actually, the Xenars are older, so may not have been coated in
the same way. 

Richard Knoppow
Los Angeles, CA, USA