White Light Solar Dob?

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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colinsk

White Light Solar Dob?

Post by colinsk »

Dobson described a solar dob made from uncoated mirrors. As anyone used or built one?


colinsk

Re: White Light Solar Dob?

Post by colinsk »

Thank you! I had not seen that.

It is nice that it eliminates the obstruction. I wonder if you AR coated the first mirror for H-alpha if you could make an obstruction free mirror based h-alpha scope? In LASERs we have mirrors HR and AR coated for different frequencies simultaneous often.


Photonist
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Im an EXPERT!
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Re: White Light Solar Dob?

Post by Photonist »

Hi,

These uncoated mirror Newtonians are not actually on Dobsonian mounts, but interesting anyhow. Sorry, if I’m a bit out of topic.

I have been planning to build something in this Art Whipple truss rod style using a 200-250 mm mirror (only for imaging). Let’s see…

If I only could get it light enough for my mount. What do you think of the design? The field stop could be a good idea.

http://tinyurl.com/8863u3w
http://tinyurl.com/d52joxr

Best wishes,

Viljo


colinsk

Re: White Light Solar Dob?

Post by colinsk »

If you enclose links with the url button above the editing box they will work with a tilda.


colinsk

Re: White Light Solar Dob?

Post by colinsk »

Why not un-aluminize the secondary? Then we get 5% of 5%. That is .25%. Much better. Then we use a ND3 to 4 filter and we are visual. Hmmm....


Photonist
Im an EXPERT!
Im an EXPERT!
Posts: 303
Joined: Sat Jan 07, 2012 5:57 pm

Re: White Light Solar Dob?

Post by Photonist »

Hi,

Yes, I also wondered about his secondary as there is certainly enough light if using an unaluminized one. I haven’t even considered an aluminized secondary.

Interesting that he had no reflection problems due to the white mirror cell.

I wonder if a bit cheaper quality mirrors would do (Whipple used 1/20 λ)?

Viljo


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