Istar 150mm h-alpha project

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Pablito
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Istar 150mm h-alpha project

Post by Pablito »

Hi,

I start making my solar scope :)

I have:
- Istar h-alpha optimized 150mm F10 lens,
- carbon fibre 160mm diameter tube (painted white)
- Lunt LS100 DS II PT etalon
- BelOptic 105mm sub-ERF

I already gave instructions to machine shop to make all the aluminium parts - objective adapter, baffles, etalon/focuser adapter.

Original Istar 150F10 refractors have ca.20cm of back focus. Isn't it too much? Usually refractors have ca.15cm of back focus.
However, Lunt DS II etalon has 40mm ERF and 36mm front collimating lens on etalon. With 20cm back focus, may cause loosing some lightcone baffled by original 40mm ERF. Extending the tube and cutting back focus a little would help but can it cause other problems?
Thanks in advance for your opinions :)
Etalon.jpg
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swisswalter
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Re: Istar 150mm h-alpha project

Post by swisswalter »

Hi Pawel

shortening the tube shouldn't give you terrible problems. Just make sure you have enough extension tubes when needed


Only stardust in the wind, some fine and some less fine scopes, filters and adapters as well. Switzerland 47 N, 9 E, in the heart of EUROPE :)

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Re: Istar 150mm h-alpha project

Post by marktownley »

will the focal ratio of the Istar match the focal ratio of that 36mm collimating lens?


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Re: Istar 150mm h-alpha project

Post by Pablito »

Who knows ;)

My friend uses the same etalon with F9.5 apo and works great.


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Re: Istar 150mm h-alpha project

Post by marktownley »

Fair play, will be interesting to see how it turns out.


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Re: Istar 150mm h-alpha project

Post by Pablito »

Project completed. Works great!!!

Details with pics soon :)


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Re: Istar 150mm h-alpha project

Post by swisswalter »

Hi Pawel

congratulations


Only stardust in the wind, some fine and some less fine scopes, filters and adapters as well. Switzerland 47 N, 9 E, in the heart of EUROPE :)

from 7 am - 7 pm http://www.nanosys.ch

from 7.01 pm - 6.59 am http://www.wastronomiko.com some times vice versa ;)
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