Herschel prism Tess 1.25''

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 Omegon Tess-Herschel prisms

• The diffuse spot on the ceramic disc is ideal for aligning the telescope precisely with the Sun
• Built-in polarisation filter – adjustable brightness: shorter exposure times, observation even in light cloud cover with decent contrast
• Built-in neutral density filter: Safe observation, but the image must still be dimmed well!

Reliable connection of eyepieces and cameras:

• 2" prism has twist lock closure
• 1.25" prism has T2 thread for cameras and ring clamp

An online guide to Herschel prisms can be found here