Nasty sun filter on e.bay

[Ragnar]

Whats the Astrosolar film like?

TBH I wouldn't like the idea of letting that amount of heat into a the tube of a telescope in the first place. I can't imagine it would do mirrors, lenses, or what ever fastens them inside the telescope any good.

[Jimma]

I seen this and was nearly stupid enough to bid on it..

So glad i joined this site now... Otherwise my stargazing days would have been Ohhver before they got going!!

Jimbo.

[jabberwocky]

Item now seems to have been withdrawn from sale.

[michael.h.f.wilkinson]

Whats the Astrosolar film like?

TBH I wouldn't like the idea of letting that amount of heat into a the tube of a telescope in the first place. I can't imagine it would do mirrors, lenses, or what ever fastens them inside the telescope any good.

Astrosolar film is fine. Any scope works safely with objective filters. These prevent too much energy entering the scope. I had some qualms about using a Herschel wedge on my refractor, but that also works fine. Please note: do not use these wedges in any refractor which has any lenses in the rear (Petzval lenses or field flatteners). Unlike the front lens, which sits in regular sunlight spread out evenly over the surface, these receive concentrated sunlight on just a portion of the lens and could shatter from thermal stress. For the same reason, do not use these wedges on a reflector or catadioptric scope: the secondary mirror may shatter. Any scope with plastic focusers should only be used with an objective filter.

[Jiggy 67]

Well done to all those who contacted the seller/Ebay...item sale has been withdrawn by the looks of it

[E621Keith]

Vixen has a notice on their website warning people not to use this type of filter.

http://www.vixen.co....rt20120531.html

http://www.vixen.co.jp/cs/support9.htm

Apparently it was originally designed to be used with an 40mm aperture limiting cap, but even the manufacturer regarded it as unsafe and stopped making it since 1995.