Results 1 to 5 of 5

Thread: Mirrors: Skywatcher 20" vs Hubble Optics 20"

  1. #1
    Member davidem27's Avatar
    Join Date
    Sep 2012
    Location
    Bari, South Italy
    Posts
    32

    Mirrors: Skywatcher 20" vs Hubble Optics 20"

    Good morning y'all!

    I decided to make the big step: upgrade my 16 to a 20 inches, self made.

    I'm trying to set a stable-but-portable scope and I was looking for a lightweight mirror in worldwide markets.

    My eyes dropped onto these two mirrors: weights are really lighter than other Pyrex standard mirrors.


    The next questions are

    - What is their real optical quality?
    - How much the coating is good in these two type of glasses?
    - Is it durable through the years?
    - Has the parabolized surface made without rugosity, considering they are industrial made mirrors?

    I think these questions could be only answered by owners that had (hardly) tested and measured these optics alongside with precise benchmarks, and also have posted mirrors for many years.

    I would be glad to discuss with you about mentioned issues.


    Davide
    Davide Pistritto
    Dobson 24" f/4 - TeleVue Ethos with Paracorr 1 - Thousand Oaks filters on filterslide
    Uranometria 2000.0, Triatlas, MegaStar 5


    Beware for your CDDs! eheh...

  2. #2
    Member Ivan Maly's Avatar
    Join Date
    Dec 2012
    Location
    Upstate New York
    Posts
    537
    The Skywatcher quality control on these is "1/4 wave". See my last blog post for some pretty fine detail in M81 that I caught with mine on a cold but very stable night. I've only looked through an 18" Hubble at low-medium power; not much of a test. Good luck with your project.
    Last edited by Ivan Maly; January 12th, 2018 at 01:10 AM.
    Ivan
    20" Sky-Watcher
    deepskyblog.net

  3. #3
    Member davidem27's Avatar
    Join Date
    Sep 2012
    Location
    Bari, South Italy
    Posts
    32
    Thanks for fast replying Ivan!
    Your HII observations about M81 are very interesting.

    What is your favourite magnification, using Stargate dobson?
    Do you observe at 250-300x?
    How does the mirror works at these powers?
    Davide Pistritto
    Dobson 24" f/4 - TeleVue Ethos with Paracorr 1 - Thousand Oaks filters on filterslide
    Uranometria 2000.0, Triatlas, MegaStar 5


    Beware for your CDDs! eheh...

  4. #4
    Member Ivan Maly's Avatar
    Join Date
    Dec 2012
    Location
    Upstate New York
    Posts
    537
    I have just got the scope for Christmas and made one short dark sky run to use the rare winter clearing. 250x looked perfectly fine. I plan to use higher magnifications often and report on it in the coming months.
    Ivan
    20" Sky-Watcher
    deepskyblog.net

  5. #5
    Member davidem27's Avatar
    Join Date
    Sep 2012
    Location
    Bari, South Italy
    Posts
    32
    My ears are fully opened

    Thanks again Ivan.
    Davide Pistritto
    Dobson 24" f/4 - TeleVue Ethos with Paracorr 1 - Thousand Oaks filters on filterslide
    Uranometria 2000.0, Triatlas, MegaStar 5


    Beware for your CDDs! eheh...

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •