0.7x Super Reducer – 2

Here is a commercial unit. Finally 48mm filter thread and orientation function have been added from the prototype.



~ by tedishikawa on August 29, 2011.

6 Responses to “0.7x Super Reducer – 2”

  1. Hey Ted,

    I note the FR has an adjustable setting by sliding the inner tube and then locking down with a single (I assume from the single photo) screw.

    As an astroimager, that setup gives me some concern as to potential differential flexure at that particular point, especially as the inner tube is pulled further out.

    Also, could the potential for some slight displacement of the FR from the optical axis of the imaging setup be increased with single-screw locking?

    I truly prefer using a dedicated FR/FF, with thread connections and no movable parts, for each of the refractors, with widely varying FLs, that need such.

    Best regards,


  2. Perry,

    Thanks for your comment.


  3. Perry,

    You might misunderstand.
    Lens barrel has no stress from any weights at all.
    Reducer body outside is M57 to M57 connected.
    So there is nothing to be worried about.


  4. Hey Ted,

    I not sure I understand either, especially if this isn’t a weight-bearing piece with a camera on one end creating a moment-arm on the junction between the inner and outer tubes of the FR.

    Is this entire FR enclosed in something that is weight-bearing?



  5. Perry I do have the same concern (as I own #7866 that “doesn’t work for me” – but I have seen others having a “good” one) because that’s exactly what I do not like about it – to have only 1 screw securing the pulling-out-in inner barrel with the lenses where you set your native focal length (so as the backfocus remains constant).
    So I expect the reducer front and back end to have a threaded connection (that’s a must have) which is OK, but just the inner barrel is problably (again) only secured with single screw and that may cause it to be out of alignment with the optical axis and produce this:

    Every color channel had elongated stars in different angle. I replaced focuser, tubes, lenses, … everything so I expect my problem to be in the FR. That’s why I hope for best with this new one (that I will have luck on a quality product 🙂 ).

  6. Greetings! Very helpful advice within this article! It’s the little changes that will make the most important changes. Thanks for sharing!

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