Farpoint 85mm Square Clear Bahtinov Mask

New Clear Bahtinov Masks for even brighter star focusing images! Farpoint 85mm Square Clear Bahtinov Mask This Bahtinov Focus Mask can mount on to a Cokin P camera filter cell. Mask is 85mm square.The Bahtinov focus technique works best with longer focal lengths and becomes less useful with shorter focal lengths. The practical useful limit is around 100mm focal length or longer.(Don’t confuse focal length and camera lens size). About Bahtinov Masks Pavel Bahtinov, a Russian amateur telescope maker and astronomer, created this simple, very intuitive method and the device has universally been named after him: The Bahtinov Mask. Attach a camera to the telescope, center a fairly bright star and achieve rough focus. Then place the mask over the front aperture of your telescope by “hanging” it on the plastic screws from the front dew shield (Custom fit masks for specific telescopes are also available). Take a short exposure. The image of the star will show diffraction spikes. The “center” sp