Help processing first LHaRGB

[goldspider]

Hi everyone.

Giving mono imaging another crack, and last week I was able to get a few nights of what I hope is decent data on the Flame/Horsehead region.

Here is a link to the individual channel stacks, L, RGB, and Ha.

I'd like to combine L and Ha into a single luminance set, but so far I haven't found instructions for doing so that make sense to me. I've tried fumbling with the Compose module, but haven't stumbled on a combination of settings that resulted in a successful blend. Anyone care to walk me through a basic workflow?

Thanks as always!

[admin]

Hi,

Any advice would hinge on acquisition details - how much data for each band/channel did you acquire?

[goldspider]

Certainly!

L - 120 min
RGB - 80 min each
Ha - 200 min

I have a feeling I might need to start with gathering more RGB data.

[Mike in Rancho]

I took a quick look but didn't save anything final yet. Ivo will probably come up with the best advice and rendering.

What steps were you trying in order to combine your L and Ha?

My initial impression was that, as you say, the LRGB seemed like it could use more. Uncertain what your optical train was or what your skies are like.

There also seemed to maybe be some vignetting and other artifact issues with the channels. Possibly the flats could use some work? Finally the Ha looked way cool, though you do have a reflection halo from Alnitak I think.

Anyway what I did was compose it into LRGB using the integration times you gave, and then put Ha into the NB Accents slot. Because of all the options and settings at your fingertips when you get to the NBA module, I would think this will give you a better result in the end than trying to pre-blend the L and Ha, unless there's another reason you want to go that route?

Other possibilities may also be to blend some Ha into the R, so that it doesn't wash out so much, which I think can happen when you start using NB as or with the L.

[goldspider]

Thanks for taking a look at the data.

I would definitely like to know what is causing the color gradients and vignetting. I spend so much time trying to get my flats right but there always seems to be a problem. I do have another set of flats I took a few days later (with the train intact) that I can try, but I suspect the end result will be the same.

I don't think there's much anyone can do about reflections/halos around Alnitak. Kinda comes with the territory!

Regarding what I've tried so far, I've tried using the NB Accent feature, but all that did was overwhelm the data with red/pink (depending on what color option I chose). I tried a few combinations in Compose where I used combined L for L and Ha for red into a single composite luminance channel which I then used combine with the RGB, but that didn't really work either.

I'll try mixing in those other flats, and post a more coherent reply here when I've had a little coffee!

[goldspider]

Going through the data again, I probably need to re-shoot B; way too much sky background relative to other channels in DSS.

[hixx]

Hi goldspider,
there are various methods for combing datasets described. Please check out the User Notes by Guy (compose/ NBA modules) or use the inofficial manual pdf (Special techniques chapter), available on ST download page
clear skies,
jochen