The Baader TZ-3 is a Research Grade Telecentric Unit specifically designed for solar applications. It features an oversized pick up expanding lens set and 2" (50.8mm) threads on both sides, A T-2 Adapter and 2" Male / Female inverter ring are both included as standard accessories.
It has a 46mm clear aperture at the H-alpha-filter entrance side making it suitable for use with the 46mm research grade Solar Spectrum H-alpha filters. Its superior backfocus of 250mm is optimized for focal length reduction with a telecompressor and leaves suitable room for use with binoviewers. An Aplanatic design, with 3x focal length extension, it permits an f/30 beam in conjunction with ~f/10 optics systems.
The TZ-3 is optimised for use at the H-alpha wavelength of 656.28nm, where its measured performance is 0.99 strehl. It is also diffraction limited at 396 nm, the Calcium K wavelength.