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When to give up on a glass aperture filter?

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#1 paul130v

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Posted 20 January 2013 - 03:17 PM

Have been using an Orion glass filter for my Starblast 4.5, it's maybe 5 years old, i've got an inch or two of duct tape covering a few pinholes, and there are getting to be more pin holes.

Is there a better way than duct tape? I tried magic marker; it's not opaque enough to satisfy me. Do pin holes start to appear faster as the filter ages? Am I damaging it; or is it just inevitable, with time? Staff at Orion said it's customary to keep covering up those pin holes till the filter is half or more covered. ???? Since the rate of pinhole appearance is increasing, the question is How at risk am I placing my vision if I'm a couple of pin holes behind in the repair process, and I use the filter? Intuitively, it scares the *BLEEP* out of me. I didn't do solar observing at all, for years, for this fear...

I find Badder (?) film makes a nicer color; maybe I see more too; not sure. Is film actually longer lasting? Except for being physically more fragile, of course.

Is there a permanent 'instruction' for beginners at the top of this forum? (Maybe I'll go look, right now. But it's still true that the only stupid question is one you don't ask, right?)

I've used a couple of 'real' solar scopes; I suppose it's inevitable I'll fork out several hundred dollars; maybe more; but not this month, maybe not this year. And I guess that's a potential mine field, too.

Would a proper solar scope be less demanding in terms of maintenance?



Did I say that our day star is totally fascinating? :D

#2 BYoesle

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Posted 20 January 2013 - 03:47 PM

Replace it now with Astro/solar film. Film won't last as long, but is cheaper to replace, and is superior optically to a float galss filter.

Save up for a Herschel wedge...(refractor use only) :jump:

#3 George9

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Posted 21 January 2013 - 08:23 AM

I do own a 15-20 year old Thousand Oaks Optical glass filter that has no defects whatsoever. Perhaps the design is different than modern glass filters.

But I agree with Bob. I use Baader astro solar film for real observing. You can really see a difference in performance. It's not very subtle.

Over the years, I do get pinholes, and I cover them with a silver magic marker that says "paint" or something similar. It is a thicker application, and it is opaque. I replace the film when I get more than a few.

George

#4 Jim Rosenstock

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Posted 23 January 2013 - 07:01 PM

There's no danger to your eyes from a few pinholes in your filter....but the quality of the image will begin to degrade.

BTW, I concure on th Baader film, whenever it's time to discard your glass filter. Sounds like you've gotten a lot of use from it!

Jim






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