Shopping cart
is empty
Home > Glossary > Telescopes > Optics > Double Stack

Telescopes Optics Double Stack

Many solar telescopes are also available with a Double Stack.

Double Stack

Many solar telescopes are also available with a Double Stack. This means that two Etalon filters are installed, one behind the other. This reduces FWHM of the transmitted H-alpha line light to less than 0.5 Angstroms. Without a double stack, the FWHM is below 0.7 angstroms.

The smaller FWHM means noticeably higher contrast. The structures on the sun appear three-dimensional. The narrower FWHM of the filter also means the image is darker and requires fine readjustment using with the systems tuning system.

19.08.2019
We ship worldwide
Currency
Service
Advice
Contact
Universe2Go