Envin offer Glass Absorption Filters using raw material from Schott, Hoya, Kopp and a range of equivalents. The main types of Filter (using Schott type nomenclature) are:
- Ultraviolet Bandpass – UG type glass
- Visible Bandpass – BG & VG type glass
- Ultraviolet & Visible Longpass – WG, GG, OG & RG type glass
- Visible Shortpass – BG & KG type glass
- Infrared Pass / Visible block – RG type glass
- Neutral Density – NG type glass
These are available in a wide variety of size and thickness.