TS Optics Double Secondary mirror spider made of carbon fiber for highest stability and minimal diffraction effectsSuitable for Newtonian telescopes with 283-300 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
countersunk 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 281
mm. By using M5 screws of different lengths (not supplied), the spider
can be adapted to tubes up to approx. 300 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 283-300 mm tube diameter (inside)