Matsumoto Erect Image Mirror Diagonal

Matsumoto Erect Image Mirror Diagonal

Due to high demand and global product shortages due to the pandemic, please call for availability.

The Matsumoto diagonal is for those who wish to have what we believe is the absolute best image quality correct image diagonal available on the market, free from the diffraction and colour shifts introduced by amici prisms.

This is a unique mirror diagonal which utilizes two mirrors to create a non-inverted image at the output. 120mm of backfocus is required. The diagonal interfaces with a 2" sleeve on the telescope end, and 1-1/4" eyepieces on the back end. 48mm filters are accomodated under the black eyepiece holder section of the diagonal, and a 36.4mm thread allows an accessory such as a Borg mini helical focuser to be added at the eyepiece end.

Price does not include shipping and brokerage, which will be confirmed before actual payment is taken.


  • Accepts 1.25" eyepieces
  • 2" input, 1.25" output
  • Accepts 2" filters
  • Light-weight housing
  • Collimated by skilled Japanese craftsmen