ZWO 31mm CCD Narrowband 7nm Ha SII OIII Filter Set 93529 4mm Diameter

4mm Diameter

in almost perfect condition

through the use of a complex 20 layer dielectric coating stack

collimation rings are provided

203mm Parabolic Primary Mirror (Low-Expansion Borosilicate Glass)

ZWO 31mm CCD Narrowband 7nm Ha SII OIII Filter Set 93529 4mm DiameterZWO 31mm" CCD Narrowband 7nm HA SII OIII Filter Set This ZWO 31mm CCD Narrowband 7nm Ha SII OIII Filter Set is used to create high contrast deep sky images of certain objects, mainly emission and diffuse nebulae (i. e. Veil Nebula, M42 Orion Nebula, North America Nebula, Horsehead Nebula) or planetary nebulae (i. e. M27 Dumbbell nebula, M57 Ring Nebula, Helix Nebula), just to mention a few of well known nebulosities. Narrowband filter sets are