Hutech Astronomical Products
Equipment for the Serious Amateur Astronomer


Borg Intro

About the Borg Design Philosophy

Borg FAQs

Component Combo Solutions

Telescope Components

Borg 125SD

  • Featuring a collaboration between Borg and Pentax on a new objective design.
  • Modular design compatible with existing Borg accessories.
  • Native focal ratio of f/6.0.
  • f/5.1 with 0.85x focal reducer
  • f/3.9 with super reducer
  • Available with the adapters for Feather Touch Focuser and Finger Lake's PDF.
  • Utilizes available 115mm mounting rings
  • See Review Article  [1MB PDF] in Astronomy Now magazine


  • 125mm aperture, F6 (750mm focal length)
  • Objective lens cell produced by Pentax Japan
  • OTA weight: 3.5kg
  • Length : 650mm without focuser
  • Available focusers:
    • Borg (helical) 7835
    • Borg (helical) 7837
    • Feather Touch FTF-8C
    • Feather Touch FTF-M57

MTF Charts for Imaging Configurations

Borg 125SD / Moonlite 2.5" focuser configuration.

Borg 125SD #9125 basic configuration.

Borg 125SDF3.9 #B12504 configuration.
125SD System Diagram (High-res PDF version)

Note: For binoviewer use (without requiring a barlow), the [9125S] short tube is also an available option.
Sample Images (click on images to enlarge)
Leo Triplet
Borg 125SD5.1 + Canon 5DH
M8 & M20
Borg 125SD5.1 + SBIG STL11000
Markarian's Chain
Borg 125SD5.1 + Canon 5DH
NGC6357 & NGC 6334
Borg 125SD3.9 + Canon 5DH
M97 & M108
Borg 125SD5.1 + SBIG STL11000

    Bino-viewer Configuration:

EMS erecting mirror + binoviewer + short tube & Vixen Porta mount