Observing difficult, dim Deep Sky targets like Planetary Nebulae and certain supernovae remnants, such as the Veil Nebula in Cygnus from light poluted environments can be a very tricky business. This is where the Explore Scientific 1.25" O-III Nebula Filter shows its strengths.
Standing for "City Light Suppression", the Explore Scientific 2" CLS Nebula Filter is not just for observing nebulous objects, as it lets a broader swathe of wavelengths through to the observer than either the OIII or UHC Explore Scientific filters do.
More versatile than the OIII filter, the Explore Scientific 2" UHC Nebula Filter will work on a broader range of nebulous objects, due to its dual peaks in transmissions on both broader OIII lines and Hydrogen wavelengths
This high quality UHC filter is a narrowband nebula filter for enhancing globular and planetary deep sky objects. It blocks out a certain band of light to enhance contrast and detail on deep sky objects.
The Explore Scientific H-beta filter uses a characteristic property of the so called emission nebulae. Those objects glow in special colors, the so called emission lines. Those emission lines are linked to chemical elements - in this case hydrogen.