TS-Optics Bahtinov Mask for Astrophotography - D= 85mm to 120mm

TS-Optics Bahtinov Masks for convenient and exact focusing of your Astro Images The Bahtinov Mask is named after its inventor Pavel Bahtinov. This focusing tool enables precise adjustment of your Astro pictures to the focus plane of your telescope or camera lens.Attaching the Bahtinov Mask to your telescope or lens is very simple. Each mask is supplied with 3 screws. Remove the plastic from the screws, put them through the designated holes and then pull the plastic covers back over the screws. Now you can attach the focusing mask to your telescope or lens and start focusing. Practical advice from Teleskop Service♦ Using a Bahtinov Mask for focusing works especially well for Deep Sky photography. Correctors and Barlow Lenses are not a problem. ♦ Ideally you want to use a star with medium brightness for focusing. It should neither be too dark nor too bright. The lines of the Bahtinov interference pattern have to be clearly visible. ♦ The chosen star shouldn´t be positioned in the center of your live view, because most telescopes or lenses, although corrected, do not produce a plane field of view. We recommend to position the star in the outer third of your image. That way, you will achieve a better overall sharpness across your field of view.♦ Suitable for telescopes and camera lenses with a front diameter from 85 mm to 120 mm.♦ Sparing telescope attachment with three screws covered in rubbery plastic.♦ Simple and precise focusing with all cameras, e.g. DSLRs, CCDs or Astro-cameras♦ High quality and resistant plastic in matt black