[rollei_list] Re: cleaning old Rolleinars and filters

  • From: "Richard Knoppow" <dickburk@xxxxxxxxxxxxx>
  • To: <rollei_list@xxxxxxxxxxxxx>
  • Date: Sun, 22 Jan 2006 19:00:01 -0800


----- Original Message ----- From: "Eric Goldstein" <egoldste@xxxxxxxxx>
To: <rollei_list@xxxxxxxxxxxxx>
Sent: Sunday, January 22, 2006 6:54 PM
Subject: [rollei_list] Re: cleaning old Rolleinars and filters


Richard Knoppow wrote (snipped):

Part of the trouble with early coatings was not so much the hardness of the coating as their adhesion to the glass. The reference to the SVC site I gave in another post has some additional information about this.


German coatings from the early 50s was often easily scratched. It is rare to find an early Summicron or 2.8 Planar with undamaged coatings. They were soft by modern standards...

Marc wonders if by the mid to late 50's, the hardness of coatings improved to modern standards, and with only anecdotal evidence I'd say this seems right, as it is not uncommon to find lenses with undamaged coatings from this period after almost 50 years of cleanings...


Eric Goldstein
---
Rollei List

Most of the stuff on the SVC site refers to US practice but there may be some clues there. The problem is understanding the cause without more evidence of German coating practice of the time.

---
Richard Knoppow
Los Angeles, CA, USA
dickburk@xxxxxxxxxxxxx 

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