I targeted this area (night before last) after being inspired by an image down below in the DeepSpace forum.
The two images look nothing alike.
My image using a OSC has the least processing possible to produce an image (see attached).
The other image (narrow band HaLumRGB) has bright red and blue swathing clouds of nebulosity,
that obscure all of the fine detail. Sure, it looks impressive.
I have resolved it this way. Your thoughts are most welcome.
Take your trusty Canon or ZWO1600MC (OSC) and photograph a rose flower. One that is slightly pink for example.
The result is a replication of the rose. Everyone can see the subtle colour.
Then photograph the rose using narrow band filters (HaLumRGB for example).
Map the colours, recombine them etc etc. and the result can be totally manipulated.
One can create something out of nothing and can move into the realm of creative art.
This can then be misleading to the budding astrophotographer (and the general public).
Not that I am against creative art, foremost an artist (using watercolour) I know all about being creative.
In conclusion:
As I gain more experience in this field, I will be looking more closely at the work of others,
to assess what is real, and what is art...
Whenever a Narrowband filter is being used; the usual purpose is to enhance that particular signal in the image being created.
Take a hubble image, all the channels are not equal, with so much hydrogen it dwarfs the signal of the Sulfur and Oxygen. If you blended them 'normally' the image would be totally green just showing the Hydrogen. The idea is to demonstrate the three emission lines by boosting the weaker channels and creating a colour palette which helps to distinguish where the sulfur and oxygen are, as well as the hydrogen. (otherwise why bother collecting S2 and O3? - a mono Ha will do the job)
If people are adding Ha to a OSC image, it is generally to boost the Ha signal. You are able to go deeper more easily and promote the hydrogen that actually exists there and blend it in with a OSC image.
1st image below is ngc 6164 gone deep with a dslr - notice no O3 shell.
2nd Image then blended with O3 data (from the dslr and an o3 filter in front) - just checked and it was 3 hours of Oxygen data added.
that blue wasn't showing up before - and i think a good example of how narrow band filters can enhance essentially predominant RGB image.
So in some sense it is more real as it is showing what is actually there, but it is less real in terms of the image's dynamic range.
Cheers
rusty
Last edited by rustigsmed; 23-07-2020 at 11:49 AM.
I've attached my version from Wiruna which is a dark site. That's a deep shot straight RGB. The colors are more inline with Paul's shot who images from a dark rural site as well. There's plenty of grey/blueish reflection neb and some red and pink. The neighbouring starfields are more golden towards the right and bluer towards M20 top left so there's a lot of colour variations in the field. Your fov is narrower so again you'd get slightly different colors based on processing and starfield granularity. Andy's blended a lot of Ha in his shot to increase details and worked out colors accordingly because he's imaging from a light polluted environment. I guess everybody has his own take and style of processing. There's nothing misleading about it. Different techniques and conditions. Different results.
Well Peter for me all I am interested at this point in my journey is getting detail as best I can and also my lack of understanding what I am doing has me just producing pretty pictures add to that the fact that I am somewhat colour blind leaves me unconcerned with colour at this point. My biggest disappointment is after I upload here the next day I look and my images are way too saturated. When I get everything working, like dark, flats correct gain it is then I will be more concerned with colour.
My goal is to produce more natural photos down the line, much like your recent Lagoon Nebula..to me that is just like being there...
I once worried about colour but I think it is much more subjective than we credit.
Anyways later I will post a reprocess of the Rosette Nebula where it was, as it usually is for me, of making something with what I have..I have yet to gather all the data let alone do dark and flats and frankly I am lucky to get anything given my near cripple condition..not only is my mobility restricted and takes many days away from me but it demotivated me to do more I feel.
I suggest you just strive to produce as good as an image as you can do and don't worry what others think really as each images you learn stuff and there will be plenty of time to get it all correct and acceptable to the higher order of astrophotograpers.
You are doing very well.
Alex
