Bahtinov Telescope Focusing Mask
User’s Manual
WARNING! Never point a telescope at the Sun without a proper solar filter! Do not
use this Bahtinov Mask to look at the Sun! Permanent damage to your eye and
equipment will result. Block all non-filtered optical components such as viewfinders
to prevent concentrated sunlight from passing through. Never allow unattended
children to operate or be near a telescope during the day.
Congratulations on your purchase of the Bahtinov Telescope Focusing Mask. This accesso-
ry allows you to easily focus your telescope, even when the seeing conditions are turbulent.
Please read through these instructions before use.
Product #608020 for 8”, #608021 for 10”, #608022 for 12”
Installation
Thread each of the included Lock Nuts and Attachment Pegs onto each of the 3 slotted
holes on the mask (Figure 1) so that the Attachment Pegs all face the same side of the
mask. On ACF and Schmidt-Cassegrain telescopes, place the mask over the front cell of
the telescope with the attachment Pegs facing toward the corrector, and the Lock Nuts
facing away from the telescope. Slightly loosen the Lock Nuts and position the Attachment
Pegs as needed so that all three Attachment Pegs make contact with the inside of the front
cell (Figure 2). Meade’s Bahtinov Masks do not require mounting to or aligning with the sec-
ondary mirror, nor do they require precise centering over the corrector to work properly. This
method helps prevent any accidental contact with the corrector glass.
Figure 1. Attachment hardware
Figure 2. Bahtinov Mask installed
