This is 7-element optical system including one fluorite and one ED, and the perfect matching with ASI2600 and QHY 268.

BORG 90FL F3.6

I’m using other brand telescopes these days. Since then, I noticed how much I was spoiled by BORG lightweight benefit. I didn’t realize that. But I feel such BORG Series-80 advantage now. Above 7-element system is just 2.1kg!!
Key features are

  • Canon Fluorite
  • Starizona Super reducer called Apex ED (image circle 30mm)
  • Feather Touch Focuser
  • F3.6 / 325mm f.l.
  • Standard 2″ opening and perfect OTA length for visual observing with 2″ diagonal

See a test shot.

Taken with Canon RP in 1.6x crop-mode

This was 1st try with a spacer I had although I wasn’t sure it was right. I feel I need more 0.2mm – 0.3mm adjustment. But it looks promising.

BORG 72FL F3.6 will be coming up too.

72FL F3.6 (1.5kg)

As mentioned the above, it turns out the visual configuration just by removing the reducer unit.


~ by tedishikawa on February 18, 2021.

2 Responses to “BORG F3.6”

  1. The light weight was the first thing I noticed about Borgs. (Except, perhaps, for the mounting rings.) All my lenses would be Borgs, if they made some longer focal lengths. Just saying. 🙂

  2. Chris, thanks for your comment.

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