Nebula Filter H-Beta 1.25-inch 400-600 and brighter deep-sky objects like

and brighter deep-sky objects like star clusters and nebulae

Item Number 510365

But then Maxwell tells us something else interesting too: if we have electricity moving in a piece of metal

4 focal ratio is ideal for shorter exposure astrophotography

you get to enjoy the generous eye relief of the lower power eyepiece

Nebula Filter H-Beta 1.25-inch 400-600 and brighter deep-sky objects likeExplore Scientific Nebula Filter 1. 25" H Beta Range from 478nm to 496nm with peak at 489nm. Transmission 94. 5% H Beta Hydrogen is the most abundant element in the universe and many nebulae glow in the light of H beta. This line filter blocks all other wavelengths (and thereby nearly all of the artificial light) and only the emission line of hydrogen beta will pass. This filter fits all standard 1. 25 inch eyepieces and filter wheels.