Jump to content

Banner.jpg.b6007b69ccdf5c69bf18273ddfe023df.jpg

What's wrong with my telescope?


Recommended Posts

1 minute ago, StuartT said:

thanks. I have never had a good experience trying to collimate. I always make things much worse. It's supposed to be simple, but it really isn't. Maybe I should stick to refractors. Only problem is, I need the long focal length for galaxies and planets. 

Maybe check out a video on youtube of look up a tutorial on how to collimate SCT?

Link to comment
Share on other sites

2 minutes ago, vlaiv said:

Maybe check out a video on youtube of look up a tutorial on how to collimate SCT?

oh believe me, I have watched them all. I even have a book about collimating SCTs!

  • Like 1
Link to comment
Share on other sites

26 minutes ago, StuartT said:

I even have a book about collimating SCTs!

A whole book on the subject? I think you should be able to fit the essential points on a sheet of A4. Sounds like a guide to overthinking... But Newts - I never could collimate mine.

Edited by Ags
  • Like 1
Link to comment
Share on other sites

Posted (edited)
25 minutes ago, Ags said:

A whole book on the subject? I think you should be able to fit the essential points on a sheet of A4. Sounds like a guide to overthinking... But Newts - I never could collimate mine.

Precisely my point! Theoretically easy, practically impossible

Here's the book, by the way

https://www.goodreads.com/book/show/50622256-collimating-schmidt-cassegrain-telescopes

Edited by StuartT
Link to comment
Share on other sites

Kind of get your position. My first proper telescope was a cheapish Newtonian of no major make, could I see anything through it, no. I ended up taking it completely apart trying to figure out why it wasn't collimating and ultimately sent it back (secondary fixings were dire). Stuck to refractors until I decided I wanted more aperture and FL for the same reason you do. 130pds later, collimation is a breeze with nothing more than a collimation cap. Maybe it's not perfect collimation, but it works for me and that's all that matters, I can always crop my images for edge of field distortion and coma is inherent.

Edited by Elp
  • Like 1
Link to comment
Share on other sites

23 minutes ago, StuartT said:

I think I'm just going to replace this telescope. Life's too short.

I did say right at the start, it’s not a coma issue, it’s a flat field issue, a coma corrector was not what you needed IMHO, is was just an SCT field flattener….☹️

Edited by Stuart1971
  • Thanks 1
Link to comment
Share on other sites

1 minute ago, Stuart1971 said:

I did say right at the start, it’s not a coma issue, it’s a flat field issue, a coma corrector was not what you needed IMHO, is was just an SCT field flattener….☹️

It is SCT field flattener that has been used.

  • Thanks 1
Link to comment
Share on other sites

1 minute ago, Stuart1971 said:

Ok, I see it is sold as both…..flattener / coma corrector…..Hmmmm, well this is a strange one then….🤔🤔

It's not - it is just specialty item for SCT - it corrects all aberrations in design which happen to be field curvature and coma.

It would not work as regular coma corrector on newtonian as it is specifically designed for SCT

  • Thanks 1
Link to comment
Share on other sites

Taken from the advert page….so maybe an issue and spacing may be different for the Meade range….🤔

Additionally, even though the SCT Corrector is also an excellent fit for standard Meade f/10 Schmidt-Cassegrains, Starizona does not have precise data regarding the nominal designs of those scopes.

 

  • Like 1
  • Thanks 1
Link to comment
Share on other sites

Posted (edited)
46 minutes ago, vlaiv said:

Yep, it is worth trying different distances as well if they can't be sure if 92mm is correct distance for Meade.

Thanks. I shall try out a few different spacings, but I shall also look at the Celestron Edge HD 9.25" (I don't think my mount is accurate enough for the 11")

 

Edited by StuartT
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • 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.