Luminance-One Shot Colour.

[ollypenrice]

Funnily enough until my last image of the year, the Witch Head, I had never done an L-OSC picture. I'd done lots of OSC-Ha and lots of LRGB plus OSC. This time I really did it because Monique was getting fed up with me being outside so often and with the OSC I could just let it run and watch a film with her.

In a nutshell I'd say it works. I couldn't just drop the L onto the colour, I had to do it iteratively, de-noising and saturation-boosting at the first two iterations. Maybe I just didn't shoot enough colour. I had 9 hours L and only about 4 hours OSC per panel but the moon was on on my tail.

By the way, the structural detail in the L from the mono camera blows the OSC clean out of the water on this very faint object. On brighter ones I have never found that to be the case at all. (That's comparing sub for sub, not 9 hours versus 4.)

Olly

[Star Gazer]

What a tease! Show us a pickie then!

[harry page]

Hi

I have done this on many ocassions ( inc my last image of m33)

I do not find it a problem in Pi as it allows you to boost the colour/ automatic colour noise reduction

Go On try it there is a vid of it somewhere

Harry

[ollypenrice]

What a tease! Show us a pickie then!

It's on the DS board now. I didn't want to double post it!

http://stargazerslounge.com/imaging-deep-sky/168780-witchcraft-all-way.html

Cheers,

Olly

[martin_h]

I've done it in the past as well using 2 QHY9's mono and OSC and 2 ED80's. As they are on the same mount I can start them running at the same time so collect the same amount(in hours) of data..

[ollypenrice]

I've done it in the past as well using 2 QHY9's mono and OSC and 2 ED80's. As they are on the same mount I can start them running at the same time so collect the same amount(in hours) of data..

OK. Now what do you reckon is the best way to use the data? You can get both images processed, convert the RGB to Lab colour, split channels and recombine them with the mono L in the L channel. That way you use pure mono L as luminance.

But is it really best to throw out that synthetic L channel from the RGB entirely? After all, it is signal. At the very least the fainter parts might serve to reduce noise. Next time I'll be inclined to strip out the synthretic L from the RGB and paste the pure L onto it, then experiment with opacities in order to see if the synthetic channel has anything useful to contribute. I didn't do that with the Witch because I had more L signal than I had colour to fill it.

Interesting.

Olly

[martin_h]

I hadn't thought of doing it that way, in the past I've just used the L over the RGB for a straight LRGB image........Will have to have a play, need to find a target with structure and colour.