My EdgeHD optical tube assembly (OTA) has four small tapped holes along the front rim. What are they for?

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	My EdgeHD optical tube assembly (OTA) has four small tapped holes along the front rim. What are they for?

Answer All EdgeHD OTAs have Fastar-compatible secondary cells. Because Fastar (and its clone, Hyperstar) is very sensitive to centering of the lens optics relative to the primary mirror, all EdgeHDs are made with special corrector collimating screws. The corrector is then precisely centered by means of these recessed screws at Celestron before the OTAs are shipped.

This also centers the secondary mirror cell, which is the same assembly that holds the Fastar lens optics. When the secondary is removed and replaced with the Fastar lens, all the optics are perfectly centered for optimum imaging results.

Article Details

Article ID:

2401

Created On:

Jul 28 2010 06:53 PM