TS Optics Double secondary mirror spider made of carbon fiber for highest stability and minimal diffraction effectsSuitable for Newtonian telescopes with 295-310 mm tube diameter (inside)
Due to the double spider vanes of carbon fibre which have 11 mm distance
to each other, the stiffness after mounting matches the one of a metal
secondary mirror spider with vanes of 5 mm diameter.
The carbon vanes have a thickness of only 0.4 mm. This means minimal
obstruction and extremely fine, subtle spikes around the brighter stars.
The diffraction effects caused by the spider remain minimal.
The secondary holder is mounted with a central bore for M5 or M6 counter-sunk screws. 3x M4 knurled thumb screws for collimation are included in the scope of delivery.
The diameter of the spider from female thread to female thread is 293 mm. By using M5 screws of different lengths (not supplied), the spider can be adapted to tubes up to approx. 310 mm inner diameter.
Twin diffraction spikes at the stars?
Do twin spider vanes cause twin diffraction spikes at the stars? Of
course not! Once you have attained precise focus both spikes will merge
into one very fine spike.
Double spider vanes as focusing aid
Twin spider vanes are more sensitive to slight blurring due to
inaccurate focusing than a single spider vane. This makes focusing on
brighter stars easier. As soon as the spikes are clearly merged to one,
focus has been exactly reached. Of course, all popular focusing aids,
like a bahtinov mask, also work with the double spider.
3x M4 knurled screws for collimation
Suitable for Newtonian telescopes with 295-310 mm tube diameter (inside)