Jump to content

Can't afford a C14...problem solved.

RAC

By RAC
in Imaging - Planetary

Recommended Posts

RAC

RAC

Posted
  • Author
Posted

Well done! A C14 may have been beyond your budget, but you've gone one better!

Any plans for another mirror?

Maybe, I was thinking about one day doing a 20" f3.5 dob for visual only. Figuring a large mirror is like taking drugs, it's very addictive and you fell something is missing when its over.

Link to comment
Share on other sites
  • Replies 53
  • Created
  • Last Reply
SnakeyJ

SnakeyJ

Posted
Posted

About 4 months doing it most nights and all weekend. It would have been an easy 200 hours but alot of that time was due to inexperience with it being my first mirror. There was alot of back tracking when there was no need.

Hmm, 200hrs - without risking a divorce that would take me the best part of a year!   But the results are very good indeed and there must be a special satisfaction knowing that you've crafted the optics and built the scope with your own hands.    I posed a similar question myself a couple of weeks back, looking at alternatives to the big SCT route for planetary imaging - still digesting the feedback from this thread, but your build again shows that a big fast newtonian can deliver the goods :)

Link to comment
Share on other sites
RAC

RAC

Posted
  • Author
Posted

Hmm, 200hrs - without risking a divorce that would take me the best part of a year!   But the results are very good indeed and there must be a special satisfaction knowing that you've crafted the optics and built the scope with your own hands.    I posed a similar question myself a couple of weeks back, looking at alternatives to the big SCT route for planetary imaging - still digesting the feedback from this thread, but your build again shows that a big fast newtonian can deliver the goods :)

If I had the money I would have made the same scope as this but with a Royce 16" f4 conical mirror or gone with a Royce 14" or 16"dall kirkham mirror set. His conical mirrors are amazing, they hold collimation so well you forget to check it and when you do its still perfect after months of use and getting moved around. The only thing is the long wait to get the mirror(s) made. Making this one was a gamble as I had no idea if I was able to do it or not.

I would love to see some people with 20"+ tracking dobs with mirrors from the like of Mike Lockwood do some planetary imaging. There is alot of these scopes around if only they would get into planetary imaging.

Link to comment
Share on other sites
Alan

Alan

Posted
Posted

That is so impressive and the results on Saturn are proof enough of your mirror making skills.  I was under the impression that short focal ratio mirrors were harder to produce at the required accuracy but you seem to have dispelled that myth :)

Link to comment
Share on other sites
RAC

RAC

Posted
  • Author
Posted

That is stunning. Great image from a scope that is great to look at, and even better to look through, I do not doubt.

Thanks. It still gives me that WOW effect every time I get it out, I can't wait to take it out to a dark site and I so can't wait for a big Mars. I had some good seeing last night with Jupiter and the view was so much above what my Royce 10" produce I was shocked, and that was comparing back to back with the same eyepiece.

Link to comment
Share on other sites
RAC

RAC

Posted
  • Author
Posted

Really nice bit of work and lovely photo.

I got all excited when you talked about Mars being good in 2018 - then I saw your location!

Yep nice and high down here. Jupiter will also be getting better for us down here from next year on.

Link to comment
Share on other sites
Ags

Ags

Posted
Posted

We need more planets ... :-(

In your original post you showed an impressive test result showing cubic mm to go, PV and so on. How did you get that report?

Link to comment
Share on other sites
RAC

RAC

Posted
  • Author
Posted

That's a program called fugure xp. You take measurement at the knife edge with a mask on the mirror. If you google foucault you'll see lots of photo's

Link to comment
Share on other sites
RAC

RAC

Posted
  • Author
Posted

Well, this thread has both inspired and now informed me. Thanks!

It's both fun and challenging making a mirror and one of this size is even more of both of those than ever. I'm not sure if such a mirror has ever been done as their first mirror before but there is no point making a small mirror if I didn't want a small one.

You learn a lot because you have to, getting lucky and producing a good mirror would be rare.

Link to comment
Share on other sites
happylimpet

happylimpet

Posted
Posted

Im deeply impressed and I admire your sheer courage in going straight into a mirror this size! None of this 'make a 6" f/10 first' nonsense.  Big Newts are the go.... I dont see myself using anything else..and now my 12" f.5 seems a bit pathetic!

Link to comment
Share on other sites
  • 2 months later...
RAC

RAC

Posted
  • Author
Posted

I can't wait either! Thanks.

I've now made a 20" f3.8 that may be ever better than this 18" mirror but it will be in a dob scope so not really any good for imaging planets unless I power it but I plan too.

19908291616_3117954894_b.jpg

20inch f3.8 Ronchi by Raymond Collecutt, on Flickr

19926925202_c888b763da_b.jpg

20inch f3.8 surface profile by Raymond Collecutt, on Flickr

19313544883_5f6d54b479_b.jpg

20" f3.8 Image of surface by Raymond Collecutt, on Flickr

Link to comment
Share on other sites
  • 3 weeks later...

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.