After a quite long trial-and-error (8-10 different masks with different patterns and manufacturing methods) and researching of what fits best, I came up with a design for Bahtinov masks which meets all the characteristics so that I finally don’t have to worry about focusing anymore. This model if my Bahtinov masks is designed for filter threads for various lenses

This mask can be used with photographic lenses and small refractors.

What are the special characteristics of these mask?

• The Bahtinov pattern has been specially calculated and adapted for focal lengths of photographic lenses. Various other masks are actually designed for large telescopes with very large focal lengths, even if they have a small diameter
• The mask fits and was tested with focal lengths from 100 mm to 600 mm
• The same mask can be used with other lenses with the same filter diameter
• The mask is installed by putting it into filter thread ring of the lens. If a filter with the same diameter is screwed on, the mask will hold even then. A protective ring makes sure that the mask does not touch the lens surface
• I always use such a mask myself, because I still use a few photo lenses for astrophotography
• The mask comes in a storage box. The box is labeled with the side of the filter thread, e.g. "77mm"

Please select the right filter thread size in the selection list below.

Attention: the minimal supported focal length is 100mm. You can certainly use it with a shorter lens, but you will need large magnification on the display or an external monitor.

Please note that these masks can tilt and fall out at around 5˚ before the vertical position. Well, on so close to the horizon there are hardly any stars to see well... 😉

Please note that the material of the mask is heat-sensitive and starts deforming at 60˚C and hotter. Thus, the mask should be not left in the sun, for example.