12" White light Newtonian

Frankenscope? Let's see it!***be advised that NOTHING in this forum has been safety tested and you are reading and using these posts at your own peril. blah, blah, blah... dont mess around with your eyesight when it comes to solar astronomy. Use appropriate filtration at all times...
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AndiesHandyHandies
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12" White light Newtonian

Post by AndiesHandyHandies » Thu Oct 24, 2019 8:09 am

Hi

I now can use some bits for a 12" dobsonian.
I lent the mirror to someone and they cleaned it without asking and took half the aluminium off!
'Home' aluminised at my first club and some pre-cleaning artefact in the coating it looked like.

So might as well take it all off.

Whats the best narrow band filter (s) to use?

Rod points out he used a 10" Newtonian for solar projection for hours with no issues.

Andrew



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Re: 12" White light Newtonian

Post by MalVeauX » Sat Oct 26, 2019 2:06 am

Heya,

Well, use a 656nm (Astronomik HA 12nm) filter for poor seeing.
Use a 395nm or 430nm (Andover or Edmund Optics) for higher angular resolution with very good seeing.

Very best,



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Re: 12" White light Newtonian

Post by AndiesHandyHandies » Sat Oct 26, 2019 7:45 am

Thanks.



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Re: 12" White light Newtonian

Post by bart1805 » Sat Oct 26, 2019 8:20 am

Don't forget to de-aluminise the secondary mirror!



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Re: 12" White light Newtonian

Post by marktownley » Sat Oct 26, 2019 10:58 am

bart1805 wrote:
Sat Oct 26, 2019 8:20 am
Don't forget to de-aluminise the secondary mirror!
Depends how much light you want coming through 😉


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Re: 12" White light Newtonian

Post by bart1805 » Sat Oct 26, 2019 11:23 am

marktownley wrote:
Sat Oct 26, 2019 10:58 am
bart1805 wrote:
Sat Oct 26, 2019 8:20 am
Don't forget to de-aluminise the secondary mirror!
Depends how much light you want coming through 😉
Yep, you are absolutely right!



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Re: 12" White light Newtonian

Post by allhoest » Sun Dec 01, 2019 4:40 pm

"Don't forget to de-aluminise the secondary mirror!"

If you do so, you will have a very strong filtering.
Maybe you want it that way, but keep in mind that you will have to collimate it!



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Re: 12" White light Newtonian

Post by christian viladrich » Fri Dec 20, 2019 10:59 am

As said by Alexandre, just keep the primary uncoated and the secondary coated.
Regarding filters, it all depends on the seeing conditions at your place. A 300 mm is a bit of a large telescope for solar image.
The range of usual filters are :
- deep-sky Ha, when seeing is bad,
- 540 nm, when seeing is good,
- deep-sky OIII, when seeing is pretty good,
- 430 nm, when seeing is excellent,
- 396 nm, when seeing is perfect.


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http://www.astronomiesolaire.com/

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