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Barlowing with Baader fine tuning rings

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#1 Matt Wallin

Matt Wallin

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Posted 15 February 2013 - 02:36 AM

I just ordered an Astro-Tech 2" (GSO)2x ED barlow. It seems like most owners are very impressed with it, especially for the price. I intend to use it with ES 100* eyepieces, and I'd really like to keep from cantilevering those huge and heavy eyepieces out any further than necessary. The lens cell has M48 threads on it and can be threaded into 2" eyepieces for ~1.5x, from what I've heard. I was wondering if anyone had experience using spacers, such as Baader fine tuning rings, to increase the barlow amplification. If so, which lengths did you use, and what sort of limits did you encounter?

#2 Starman1


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Posted 15 February 2013 - 05:54 PM

Baader FT ring--14mm
Baader FT Ring--28mm
TeleVue barrel extender--30.5mm
Combinations of the above: 42mm, 44.5mm, 58.5mm
So all of the above would work with the lens as a separate piece.

And, you could find a variety of extenders to be used (not all barrel extenders are the same length as the TeleVue, for instance) to achieve a variety of magnifications.

All-in-all, a worthy experiment.

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