Custom Scientific Hydrogen-Alpha filter (H-alpha) 1-1/4" threaded cell
656.3, 3.0nm bandpass
Please note that this is not the less expensive 4.5nm or 6.0nm bandpass!!!! This is the good one!
Excellent condition, no scratches or blemishes.
H-Alpha 656.3/3.0 1-1/4". Hydrogen-alpha 3.0nm passband. This filter is designed for non-solar imaging, and is used to image deep-sky objects that emit in the h-alpha passband.