Farpoint Adjustable Tri-Bahtinov Mask — 13" to 16" OTAs solar-filter The result is smooth and

The result is smooth and positive azimuth movement and much greater stability

1/10 wave or better

Sold separately

"text": "The FDCM holds the camera in a fixed orientation on the quick-release saddle

Rule of thumb: the bigger the gap between your tube and the ring

Farpoint Adjustable Tri-Bahtinov Mask — 13" to 16" OTAs solar-filter The result is smooth andNot 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 13" to 16" 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