A Herschel prism offers particularly high resolution for solar observation and photography.
- Can only be used with refracting telescopes. For reflecting telescopes, please use solar filters in front of the objective instead!
- Use with caution! Not suitable for inexpensive telescopes with plastic parts inside! These could melt or even smoulder if the telescope is not aligned precisely with the sun!
- Always supervise telescopes that are aligned with the sun using a Herschel prism !
96% of the sunlight passes straight through the prism and hits the ceramic disc. This converts the light into heat. Therefore:
- 2" prism usable up to 150 mm lens diameter
- 1.25" prism up to 120 mm.
Telescopes with a larger aperture can of course be dimmed.
Advantages of the Omegon Tess-Herschel prisms
- The diffuse spot on the ceramic disc is ideal for aligning the telescope precisely with the Sun
- Built-in polarising filter – adjustable brightness: shorter exposure times, allowing observation even in light cloud cover with decent contrast
- Built-in neutral density filter: Safe observation, but the image must still be dimmed sufficiently!
Reliable connection of eyepieces and cameras:
- The 2” prism has a twist-lock mechanism and adaptors for T2 threads
- The 1.25” prism has a T2 thread for cameras and a ring clamp
An online guide to Herschel prisms can be found here
