Orion 5587 1.25-Inch H-Alpha Extra-Narrowband Filter Take high-contrast CCD images of emission nebulas in full moonlight or in extreme light pollution with this specialized extra narrowband h-alpha astrophotography filter Astrophotography filter provides 90% transmission at H-alpha line of 656.3nm and very narrow bandpass of 7nm Reveals subtle nebular details which are usually washed out by contrast-killing broadband light Also works great in conjunction with other filters for more advanced astrophotography techniques Astrophotography filter threads into standard 1.25" camera nosepiece, Orion Nautilus 1.25" Filter Wheel or Orion Multiple 1.25" Filter Wheel