FP412R Bahtinov Mask for Celestron 11" RASA
Bahtinov Mask for Celestron 11" RASA
The Bahtinov will produce Cross-shaped stars, with one clear line that moves along the cross as you focus. When the line is centered on the cross, you should have achieved perfect focus.
How it Works
The slits in the mask are the focus assist, when the star is in focus it will appear on your screen display as an “X” with a line through the center (see above).
These mask will work equally as well on the end of a scope or on the end of a dew shield on top of that the mask itself does not need to be perfected centered on the scope this is due to the angle of the slits themselves.
Select a bright star, this will be your guiding object. Place the Bahtinov focusing mask on your telescope’s lens and secure it into place using the provided rubber tabs.
The slits in the mask design create a set of diffraction spikes on the star that will assist in the accuracy of our focus. It will appear on your DSLR display screen or computer as an “X” with a line through the center (when in focus).