Re: (ATM) ATM - lens cement and thermal stress
Stephen Tonkin (astro@aegis1.demon.co.uk)
Sat, 19 Aug 1995 20:48:25 GMT
In message <9508141836.AA15054@haida.dao.nrc.ca> Scott Roberts writes:
>
> I am looking for information on cementing lenses.
>
> Specifically, I have a 74mm (~3") diameter FK54 and Silica lens set
> that I want to assemble. The problem is that the optics will be
> subject to large temperature variations and their thermal coefficients
> are very different.
>
> Silica: 0.6x10^-6 / C
> FK54: 14.6x10^-6 / C
Too much stress on the _glass_ (which will distort), even if you find
an adhesive which will "hold" the elements.
Try oil.
Clear Skies,
Steve <sft@aegis1.demon.co.uk>