[rollei_list] Re: WTB: SL66 thingies

  • From: Don Williams <dwilli10@xxxxxxxxxxxxx>
  • To: rollei_list@xxxxxxxxxxxxx
  • Date: Sun, 21 May 2006 21:23:46 -0700

At 09:12 PM 5/21/2006 -0700, you wrote:

----- Original Message ----- From: "Don Williams" <dwilli10@xxxxxxxxxxxxx>
To: <rollei_list@xxxxxxxxxxxxx>
Sent: Sunday, May 21, 2006 8:45 PM
Subject: [rollei_list] Re: WTB: SL66 thingies


At 07:01 PM 5/21/2006 -0700, you wrote: 
Peter,

Yeah, you do 99.5 for say 11 air to glass surfaces and you
end up with a number that is not quite so large.

BTW, you should tell Eric that you drive a La Salle, not a
DeSoto!

Jerry 

Jerry,

What lens design do you have in mind that has 11 air to glass surfaces?



Don Williams
La Jolla, CA
I can't answer for Jerry but there are plenty of zoom lenses that have this many. They would be impossible without effective anti-reflection coating.
I questioned Eric because I am curious about his source, not because I think he is wrong. I have simply never seen a statistic on rejection rates of lens coatings. The technology involved is very advanced now. Thin film deposition is used in the manufacture of electronic components and elsewhere. Multiple anti-reflection coating on camera lenses is fairly simple compared to some other applications of the same or similar technology.

I wasn't questioning the general number, but just wondering how you end up with an odd number of surfaces. I know there are special situations in which the film or other media is coupled to the final lens surface by a liquid, but other than that I don't understand the number 11.


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



Don Williams
La Jolla, CA

Other related posts:

  1. Home
  2. rollei_list
  3. Archive
  4. 05-2006