what's black and white and red all over?
...an image using an Ha filter.
to the abundance of hydrogen, you'll get some signal all the way from
the highest energy to the lowest energy regions in a nebula right up to
the ionization front, with rare exceptions. thus hubble pallet images
using SII, Ha, and OIII are typically teal and gold rather than red
green and blue.
I chose a M76, a relatively bright planetary nebula with some detail, for the first image with my new narrower Helium II filter (4nm from chroma).
a quick blink of the mono channels for this one showed me that the brightest signal areas were not quite completely separated
which means a scientifically assigned color pallet will give the full spectrum...
a rainbow in space:
Helium II blue, (so faint it's stretched), Oxygen III linear green, Nitrogen II linear red
here's the color image with a log stretch which works quite well for bright planetaries with faint shells:
a healthy does of NII was applied as luminance
here's another variant with OIII assigned to teal rather than green:
Helium II as blue with a green continuum filter as red and green (both new filters):
still looking for the pot of gold
8" LX200R, SX Trius 694 and QSI 660 binnedx2 to 0.8"/px
astrodon 3nm NII, 3nm OIII, chroma 4nm Helium II filters
NII 35x20min OIII 17x20min HeII 27x20 min
never enough exposure time...