The Horsehead Nebula 馬頭星雲

M77 - NGC1055

LPS P2 filter with additional Lumcon H-Alpha filter

Sigma Telephoto Zoom Lens of 150-500mm FL at 500mm
Canon EOS Rebel T3, self modded,
ISO3200, Exposure time 2 minutes,
27 lighs, and 20 darks and flats each,
Lumicon H-Alpha filter with IDAS IPS P2 filter, combined together, used as a semi-narrow band filter.
The transmission wave length is between 635 nm and 680nm , roughly 45nm band width at the half peak. Note the H-Alpha peak is 656 nm.
Please refer to
http://www.sciencecenter.net/hutech/idas/filtplt.htm
for LPS P2 and
http://www.astrosurf.com/buil/filters/curves.htm
for Lumicon H-Alpha pass filter (this filter is a low pass filter, not a band pass filter).
The star images were superimposed with the shots (45 seconds exposure frames) taken without the Lumicon filter

LPS P2 filter only

Processing of the M42 photos taken by LadeII
Photos: The exposure seconds are 30, 60, 120 and 240 seconds.

30 seconds exposure	60 seconds exposure
120 seconds exposure	240 seconds exposure