For all SolarSpectrum H-alpha filters - with 2" male thread to 2" male thread.
SolarSpectrum H-alpha filters require parallel light with a beam path of at least f/30. This is achieved by extending the focal length with a telecentric system. Due to the focal length extension, the entire sun is no longer visible when using eyepieces with focal lengths of 30 to 35 millimetres on many telescopes.
The two SolarSpectrum telecompensators are mounted directly on the filter on the eyepiece side and reduce the previously extended focal length by a factor of 0.4 or 0.7, with the result that the entire solar disc with protuberances is now visible again.
For photographic applications, the telecompressor is used to adjust the focal length to poor seeing conditions and/or to increase the field of view.
Working distance: 74 millimetres (distance to camera sensor), optimised for videography and imaging of the entire sun. 16-millimetre corrected image field.
