Once upon a time in a galaxy far, far away, there was this fellow called
Dr David Malin who revealed the universe to the world in real and natural colour.
While there has been some opinion, masquerading as fact, about the real colour of the Tarantula nebula is being "dealers choice". This is simply false.
Work done...sometime ago...by Helmholtz pretty much established the colour theory of how a warm human eye perceives the world.
Film, sensor and camera manufacturers like Kodak, Ilford, Nikon, Canon etc. then went to some effort to deliver technology that faithfully reproduced colour
on print, digital screens and other media. Wedding photographers who constantly make the bride's face look green generally don't last long hence colour fidelity was paramount.
The problem for astrophotographers is most astronomical objects are really dim
and simple observation doesn't work on them.
Ever wonder why the backyard looks like shades of grey under moonlight?
The photopic cells in you retina (cones that sense red, green and blue light) become dormant and the scoptic cells (rods) which don't register colour, do all the sensing. The point?
When looking at the sky, we don't have vision sensitive enough to perceive the real colour of deep sky objects. Yet this colour is just as real and consistent as your
green (or maybe yellow
) lawn or favourite flower when seen under the light of day.
Seems the lost art, that Malin laid the foundations to, is to take calibrated deep exposures in Red Green and Blue light, then combine them to create a full and *accurate* colour image.
Pointing your imaging rig at a colour test chart, then taking red, green, blue exposures....or simply adjusting the RGB gain on a *OSC camera will get you close. (*full spectrum OSC...daylight cameras filter out H-alpha light)
And guess what? The Tarantula nebula really is shades of red.
If it isn't, then some other part of the spectrum has been added to the mix.
There are no rules that forbid this. Only colour fidelity is lost.
...... hummmm!
