[ATM] Multicoatings

[lenses@adelphia.net]

Keep it simple.
The glass is Bk-7, Magnesium Flouride will be broad band through the visible and put the low point for reflection at 1.3% Very inexpensive but NOT what the rest of these vendors ( I assume) put on thier optics.
Next coating is a simple 3 layer coating consisting of QHQ (Quarter wave,Half wave,Quarter wave) of medium,high, then low index material.
This will have an average reflectance of 0.5% from .45-.65 microns, if applied well the glass will be almost invisible to visible light.
This is probably what these vendors apply its a very common simple coating to apply.
Depending where your at and how much money you want to spend, a quess is around $720.00 for both surfaces coated. This is going to vary widely depending also on the size of the optic.  Don't ask for a multi-layer coating ask for a reflection specification that is reasonable across the visible wavelength. Most vendors have these standard coatings listed with graphs on thier web sites.
Good luck,
Pete
---- Chris Dalla Piazza <dalchri at hotmail.com> wrote: 
> Here's another way to ask the question.  What do Meade, Celestron, Televue, 
> Takahashi, and Astro-Physics use to coat the optics on their refractors and 
> the corrector plates of their catadioptrics?  If I needed to get a corrector 
> plate from my SCT recoated, where would I do this and what would I ask for?
> 
> This is for the corrector of my recently completed Lurie-Houghton Newtonian.
> 
> Thanks again for suggestions!
> 
> 
> >From: "Chris Dalla Piazza" <dalchri at hotmail.com>
> >To: atm at atmlist.net
> >Subject: [ATM] Multicoatings
> >Date: Tue, 07 Aug 2007 11:25:05 -0400
> >
> >I have a few questions about multicoatings I was wondering if someone could
> >help me with...
> >
> >Do multicoatings increase transmission or do they only eliminate 
> >reflection.
> >
> >I understand there are a few different types of multicoatings.  Is there a
> >standard or most widely used coating?
> >
> >My priority is that there be no weird colors when imaging rather than 
> >really
> >high transmission.  What coating would you recommend?
> >
> >Finally, who would you recommend?
> >
> >_________________________________________________________________
> >Booking a flight? Know when to buy with airfare predictions on MSN Travel.
> >http://travel.msn.com/Articles/aboutfarecast.aspx&ocid=T001MSN25A07001
> >
> >_______________________________________________
> >ATM mailing list http://www.atmlist.net/
> 
> _________________________________________________________________
> More photos, more messages, more storage—get 2GB with Windows Live Hotmail. 
> http://imagine-windowslive.com/hotmail/?locale=en-us&ocid=TXT_TAGHM_migration_HM_mini_2G_0507
>