After quite a long trial-and-error (8-10 different masks with different patterns and manufacturing methods) and researching what fits best, I came up with design of a Bahtinov mask that meets all the characteristics so that I finally don’t have to worry about focusing anymore.

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 and small refractors. Various other masks on the market 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 and comparable focal length
• I use a similar mask myself, because I sometimes use a few photo lenses with the same filter thread size for astrophotography. This is the best solution I'm aware of
• The mask comes in a storage box. The box can be labeled

Please specify the outer diameter of the sun hood of your lens or refractor. Note that a certain tolerance is added to this size so that the mask will fit with certainty.

If you need a custom text on the storage box, please send me this text of the inscription with a message after purchase. Please note that only one line is possible. One letter takes around 0.22 of the filter size, i.e 17 letters fit on a box for 77mm filter thread size. If you do not order a custom text, the size of the filter thread will be used.

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 50˚C and hotter. Thus, the mask should be not left in the sun, for example.