Re: [APML] OT: AP Oil Spaced Lenses

[Michael Cole <mrcolewa@home.com>]

Looks like I will not be getting an astro physics refractor.  My wife
says the oil spots from my Harley are enough.

:-(





Jim Janusz wrote:
> 
> Hey John,
> 
> You just gave me some info. I was unaware of.  I thought the 7-7 was oil
> spaced.  Now I understand what the slight stains are at the very outer edge
> of the cell.
> 
> Gel, well I'll be damned!  Did Roland say what the gel is made of?  Is it
> petroleum based?
> 
> Jim
> ----- Original Message -----
> From: John Gleason <dvj@earthlink.net>
> To: <astro-photo@seds.org>; <astro-photo@seds.org>
> Sent: Wednesday, June 21, 2000 4:27 PM
> Subject: RE: [APML] OT: AP Oil Spaced Lenses
> 
> > Chuck,
> >
> > My 7" f/7 is gel spaced not oil spaced. The gel used is from the fiber
> > optics industry.  I can see changes in the gel when there is thermal shock
> > to the cell during cool down.  The cell is sealed, but there does not
> > appear to be a manifold to compensate for contraction or expansion of the
> > lens elements.  Roland told me so.  The 6" f/7.1 that I also own (7 years
> > old) is oil spaced as per Roland.  This appears in early 90's AP
> > literature.
> >
> > jg
> >
> >
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-- 
Michael Cole
Urban Imager Astrophotography Website
http://members.home.net/mrcolewa/interest.htm

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