narrowband filters 36mm Ha+OIII+SII ZWO 1st gen For Sale
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narrowband filters 36mm Ha+OIII+SII ZWO 1st gen:
All filters in perfect condition!
Some of my original pictures in listing, others in Data
- Size: D=36mm
- Thickness: Thickness 2.0+/-0.03 mm polished to ensure accurate 1/4 wavefront over the both surfaces
- About 90% transmission at H-alpha line 656nm (H-Alpha filter )
- About 90% transmission at SII line 672nm (SII filter )
- About 90% transmission at major OIII line 500nm (OIII filter )
- Infrared wavelength 700-1100nm cut-off
- <0.1% transmission of off-band, OD3(Optical Density)