The size of this mask is adapted for the lens hood of Sky-Watcher Esprit 100ED. This mask is based on my other designs and is only specially calculated for the Esprit 100ED, because I use this telecope myself.

The mask is available in two variants of the Bahtinov pattern:

• calculated for the original focal length of 550mm with the classic Bahtinov factor of 200
• for a shorter focal length of 360mm, which 0.65 of the original focal length with APEX ED-L corrector and reducer

I recommend the second variant, which it also works well with 550mm, whereas the first variant is a bit too coarse for the 360mm focal length.

Both variants can be ordered with a storage box or without.

Unlike other Bahtinov mask on the market, the Bahtinov pattern of the mask has been calculated and adapted specifically for shorter focal lengths. This is often not the case with other masks, because many offers are actually designed for large telescopes with very large focal lengths, and are therefore too coarse.

Please note that the mask will sit with a slight play on the lens hood. However, this does not affect the function of the mask in any way. Please note that the material of the mask is heat-sensitive and starts deforming at 50˚C and hotter. The mask should be not left, for example, in the sun.