PREOWNED ITEM
 
Technical Data
FWHM：7±0.5nm
Glass Thickness 2.0+/-0.03 mm  (31mm/36mm)
Fine-optically 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)