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View Full Version here: : part of NGC253...first good LRGB


kinetic
30-11-2008, 10:12 AM
Hi all,

Here is the first test from last night of my
LRGB technique and also of my homemade 4 position
filter wheel.
I'm a complete novice at LRGB....all I have ever messed
around with are modded colour webcams (ICX-098 based)

50x 10 sec Luminance
50 each RGB x 10 sec
10 darks.
No flats
No Bias

GSO 12" f5 Newt focus
DSI Pro II / Baader IR filter, Meade RGB filter set.

regards,
Steve B

jase
30-11-2008, 12:14 PM
Not a bad effort Steve. LRGB takes some work to do well. As you introduce the luminance to the RGB data, you'll commonly find the intensity will desaturated the colour. There are a few ways of counteracting this. Probably one I use regularly or injunction with other methods is to layer the luminance twice. The first time, drop the luminance opacity down to ~50% and flatten the image (this becomes as so called "superRGB" layer). Boost the colour saturation of this layer. Then paste the luminance again, but this time at ~90% opacity. You end up with an LLRGB composite. This process makes it easier to manage the colour saturation instead of tackling the situation introducing the luminance at 100%. Look forward to seeing more.

kinetic
02-12-2008, 06:17 PM
Thanks Jase for the helpful advice.....

So far I'm just keeping everything equal just to practice
the workload...wow what a workload compared to
modded webcams :)

Last night I got a good 100 Lum of Homunculus but only
managed 70,50 and 30 RGB respectively(cloud) , so figured I
would have to cut them back to 30,30,30 in the stack.
Not sure of the logic here, but keeping them all equal
should keep the signal to noise all on a par for
practice.

Turns out, Eta Car result ends up with a 'Tarantula Neb' type
horrible purple hue, so I adjusted it to suit what I thought was
a closer representation.

Having fun though....

Cheers,
Steve

Attached: not fully cropped LRGB Eta Car from 02-12-2008