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Posts Made By: David Sanders

May 29, 2004 12:39 PM Forum: Telescope Making

scratches in mirror surface

Posted By David Sanders

I need advice about a diagonal that I purchased which has tiny scratches on the coating that appears to have been caused by fine particles trapped in cotton packing which rubbed against the surface over a long time probably by taking mirror out and replacing in box.
Question is: Will recoating eliminate the fine scratches? I can not tell if scratches are any deeper than the coating so I'm mostly looking for examples of when you have sent off mirrors with scratches where they still there when mirror was returned.

October 17, 2004 02:46 PM Forum: Telescope Making

Pyrex or plate glass

Posted By David Sanders

Would anyone happen have any suggestions on how to determine if a primary mirror is made from pyrex or plate glass other than taking the manufacture's word for it.

March 6, 2005 06:46 PM Forum: Binoviewers

Meade 5000 Pl 14mm and other EP choices

Posted By David Sanders

I just ordered my first Binoviewer Friday (The Dink II with duel arm X switch). Looking for good planetary eyepiece of 14mm under $100 each. Saw the new Meade 5000 Pl 14 add and was wondering if anyone has tried any of these or others in the line. All opinions welcome. While I'm at it I should also ask about the 14mm Orion Lanthanum. The reviews I have seen indicate they are sharp and contrasty but do not transmit as much light as other designs Wondering if the extra light lost would be critical in a binoviewer since the image brightness is reduced anyway. I have a 24 Pan to match the one I already own and a pair of 16 Konigs coming.

October 18, 2004 06:32 PM Forum: Telescope Making

Pyrex or plate glass

Posted By David Sanders

Thank's for the suggestions everyone. The mirror I'm trying to ID does appear to be quite transparent and it seems to have a very slight green tint so I will question the company that made it as it is supposed to be pyrex.