Re: [ATM] Klaas Honders Astrograph

[Dominic-Luc Webb <dlwebb@canit.se>]

On Wed, 22 Aug 2007, Richard F.L.R. Snashall wrote:

> Actually, a 10 mm thickness of FS has an internal transmission of
>  > 80% down to about 170 nm.  That narrow range may be a bit wider.

I probably should have kept quiet on this UV issue, but yes, some
specialized grades of quartz/FS have good transmittion down to 170
nm. Many cannot, as I have learned (use it in my work). Revising my
statement, "most glass". Specifically, BK7 vs FS: yes there is
difference in the IR. I have yet to polish off my pieces to offer
relevant scan for actual glass you would get from Newport, etc. I
checked a while back before working these surfaces.

I do not know what wavelengths you had in mind. I can easily scan
from 200 to 800 nm. I can measure around 1200 nm with some more
effort. I could guess you mean R and I bands in UBVRI.

Dominic


_______________________________________________
ATM mailing list http://www.atmlist.net/