The Bahtinov mask for the Seestar S50 smartphone makes astrophotography easy. One of the critical points for good quality astrophotography is focusing. There are many aids for this, one of the best being the Bahtinov mask, which has rectangular holes cut at different angles to each other. Put it on the front of the telescope and forget that focusing is a complicated operation!
When using a Bahtinov mask, 3 pairs of diffraction spikes appear around the stars, the middle of which moves during focusing. When this is observed exactly between the other diffraction spikes, sharpness is ideal.
The mask is made of a material that can withstand temperatures up to 80°C and is 3D printed.
