This Bahtinov Mask will help you achieve focus in your astrophotography imaging train. The mask is specially designed to cause light diffraction in an X pattern with a line in the middle. The goal is to get the line in the middle of the X. Use a bright star with this mask on your telescope or camera lens to see the diffraction spikes and adjust your focus accordingly. This mask can be used on a Rokinon or Samyang 135mm, or a refractor telescope such as the Apertura 75Q or Skywatcher Evolux 62ED (select your telescope or lens in the options).
