Takahashi  FSQ 106
Paramount ME
Baader  NB filters

Bicolor image:

Ha =  30 min x 32
OIII = 30 min x 48


Processed with
PixInsight & Adobe PS

Data acquired Fall
2014 from backyard  
observatory in PA
The famous North America
Nebula is an emission nebula
in Cygnus. Here the nebula is
displayed using two narrow-
band filters that capture
specific emissions of hydrogen
and oxygen ions (Ha and OIII).
The former is in the red portion
of the spectrum, and the latter
in the blue -- these are
mapped to the red and blue
channels, respectively, in the
resultant RGB image -- the
green channel is synthesized
from the other two using a
technique in Photoshop
(modified bicolor approach
courtesy of Steve Cannistra).
      The North America Nebula
                  NGC 7000
     Click on image to enlarge