Farpoint Adjustable Tri-Bahtinov Mask — 14" to 17" OTAs Universal Focusing is made easy with

Focusing is made easy with JMI MotoFocus - Astro-Tech AT65EDQ Rack-and-Pinion Focuser

The bar drawing shows the hole pattern and measurements

It was designed to vastly outperform “bargain brand” filters at only a slight increase in price over those low performance filters

From then on

That lets you attach a Schmidt-Cassegrain accessory — an SCT star diagonal

Farpoint Adjustable Tri-Bahtinov Mask — 14" to 17" OTAs Universal Focusing is made easy withNot sure this is the right mask for your telescope? Use our Focus Mask Finder match your scope to the right Standard, Tri Bahtinov, or Hyperstar RASA mask. Adjustable Tri Bahtinov focus and collimation mask for OTAs from 14" to 17" front aperture. Sets onto the front of your telescope, gives you focus AND a collimation check from a single short exposure, and lifts off cleanly when you're done. The adjustable peg system fits any scope in this aperture