M33 Triangulum

[ApophisAstros]

agreed.
Roger

[MarkS]

L channel typically picks up much fainter structures than the RGB channels that are added over the top

When I stack the RGB together, it doesn't contain anything like the detail that the luminance channel contains.

Exactly!  That's precisely the problem - the fainter parts of the image therefore have no colour information.  If all the imaging time is devoted to RGB instead of spending the greater part on the L-channel then the colour information goes much deeper than when treating RGB as an afterthought.  In addition all parts of the image, from the faintest structures to the brightest, have colour.  You can see this in any of my images.

But as I said before, such discussions often generate much controversy because the LRGB imagers are set in their ways 

Mark

[Carole]

It still has colour information it just lacks such clear detail i.e. the shape and structure of the nebula in the RGB.

I can see we totally differ on this topic. 

Carole

[ApophisAstros]

This is the most replies i have had on any post...lol
Roger

[MarkS]

This is the most replies i have had on any post...lol
Roger

   
I won't say any more on the LRGB vs RGB subject but for those interested, the debate can be found here: 
https://www.cloudynights.com/topic/575319-lrgb-versus-rgb-a-fascinating-debate-at-the-highest-level/

Mark

[JohnP]

Not that I'm in a position to comment as haven't imaged for near on 5 years but have to say I just prefer mono imaging  - Not a fan of colour & definitely not false colour narrow band images - I just don't like them. I just prefer the details you can see in a single B&W Ha image. I suppose it's a bit like regular photography some people prefer B&W to colour... So for me its a B&W cooled CCD with an Ha filter stuck on front.

Carole - have to say I concur with all your comments in above thread.

John

[Carole]

I have read a huge chunk of the cloudy nights thread, and all I can say from my perspective is I am not analytical like Mark is, but I can only say "proof of the pudding", on the odd occasion when I have reverted to using a DSLR (for various reasons), I just say to myself "Oh yes, I remember why I stopped using one and went over to mono imaging".   

Of course I have never tried using a DSLR like the A7S, so my opinion on that could be quite different. 

Thanks for your comments John, from my own perspective I am completely the opposite with B&W which just leaves me cold, and to me looks like an unfinished image, but each to his own.

For your interest I made up a comparison of RGB, Luminance and LRGB all from the same kit same night.  To be fair I did bin the RGB and there is less time on it, (but I don't have any other examples to hand).  I think you can see how much fine detail (especially the dark nebulosity) that shows up in the Luminance layer.  I did an extra colour stretch in the LRGB version.  The RGB on its own could not be stretched any more without creating something horrible.

I haven't bothered to balance the colours or the gradient in the LRGB image, or deal with the halos as this is just a "showing the detail" exercise.

You might find it easier to see this image on Astrobin:
https://www.astrobin.com/full/357769/B/?nc=user



Sorry we have hijacked your thread Roger, but as you are just getting into mono imaging, I am sure you are finding all this discussion useful.

This is an attempt in early 2017 to try to get a DSLR shot of M78, admittedly it was from home with a LP filter, I gave up after 7 x 5mins as I could see it was a waste of time. I don't have any DSLR taken of this target from a dark location.



Carole

[The Thing]

This is the most replies i have had on any post...lol
Roger

Shame we've all hijacked it!

[ApophisAstros]

I meant it as a joke , , excellent reading tho.
Roger