Optolong's Texas Red Filter is optimized for the Texas Red dye with specific Texas Red excitation and emission properties. It is ideal for Texas Red Spectrum imaging.

https://optolongfilter.com...

My picture of crescent nebula NGC6888, placed in Cygnus constellation 4700 lights year away from earth. With L-extreme filter. Picture with stars removed to watch nebula details. Nebulosa creciente NGC6888 . Sin Estrellas para apreciar detalles. Madrid. #cielosESA #optolong