First Time Processing SHO with APP (M31) Help Please!

Sounds like you probably meant to do it in HSO, not SHO. A standard HSO will map Sii to red, Ha to green (very apparent in your image), and Oiii to blue.

In APP when I want to do the Hubble Palette in SHO I do the sliders to where I have Ha with 50% red, 100% green, 15% blue, and 50% luminance, Oiii at a multiplier of 4.000 with red at 15%, green at 90%, and blue at 100%, then Sii at a multiplier of 2.500 with red at 100%, green at 40%, and blue at 15%. I will vary the low number on each color by 5% either way to get what I want, vary the luminance on the Ha channel from 25% to 75%, the multiplier on Oiii from 3.750 to 4.500, and vary the multiplier on the Sii channel from 2.500 to 2.750.

Getting back to your image of M31, why not do LRGB and then Ha? Run the Ha at 100% and a 2.000 multiplier, L at 50%, then RGB all at 100% with LRGB all at a 1.000 multiplier.

Andy Wray:
My question would be: why are you trying to image M31 in SHO?  I would image it in RGB and maybe enhance it with some Ha data.  I did try to use your SHO data, but it was very lacklustre compared to an RGB version.

Thanks for trying. My camera is mono with SHO narrowband filters. So at this point I’m shooting SHO.

I also use a mono camera, however I have 7 filters:  Lum, Red, Green, Blue, Ha, Oiii and Sii.  This is a fairly usual setup.  For galaxies it is mainly LRGB with some Ha data and for nebulas it would be Ha, Oiii and Sii for the nebulas with RGB for the stars.  Any reason why you are limiting yourself to SHO?

Still learning. This is all new to me and my first light with narrowband was this week.

I have 5 slots in my filter wheel and some information to research.

You've got some really nice sharp images there so your equipment is working well (probably better than mine to be honest).  

With a 5 slot filter wheel (which I started with), I would use LRGB and Ha filters for most galaxies.  If you want to get into nebulas then you will probably then want to use Oiii and Sii.  I ended up swapping my 5-slot for an 8-slot filter wheel so that I didn't have to keep swapping filters.

I hope that makes sense.

If you really want to try out the narrowband stuff, I would suggest going for a bright nebula and using SHO filters on that.  I did a quick one on the Wizard nebula which is high in the sky recently as follows:



Fiddling with my scope and captured the Wizard (Added a splash of colour)

Here's a quick blast through APP and a slight tweak in Photoshop without much effort.

Fully agree with Andy, M31 is mainly a broadband target with H alpha as optional recommended enhancement .

Scotty Bishop:
Sounds like you probably meant to do it in HSO, not SHO. A standard HSO will map Sii to red, Ha to green (very apparent in your image), and Oiii to blue.

...

I believe there is a misconception. HSO means assign H to red, S to green, O to blue (i.e. HSO in same order of letters as RGB). Accordingly SHO means R=S, G=H, B=O and HOO means R=H, G=O, B=O.

Clear skies
Wolfgang

Oops, I know what I meant to say and it was what you said. Substitute the HSO in my "A standard HSO will map...." with SHO. I should not type if I am looking at other things because I will type what I am looking at not what I mean.

Scotty Bishop:
Here's a quick blast through APP and a slight tweak in Photoshop without much effort.

I do like this direction. I am going to play with things and see if I can't salvage 5 nights of shooting and then move onward with lessons learned. Thanks!

I did it in APP with H as 100% R, 15% L, and a 1.500 multiplier, Oiii as 100% B, 20% G, and 5% L, then Sii as 100% G, 20% B, and 5% L. then did a batch crop, then a remove light pollution to even the background some, then a star color calibration, then selective color and increased red, yellow, cyan, and blue saturation by 30% each, pulled back green and magenta saturation by 50%, then saved as a 16 bit tiff at the default 15% stretch. I took that into Photoshop and did camera raw increasing the darks, clarity, messing with the color balance, and then pumped the saturation and vibrance, then did a noise reduction, then a deep blue photo filter, then set the histogram spikes even on R, G, and B, then ran HLVG on weak.

Been a while since I did a super quick process like that. You should be able to duplicate this.

One piece of advice though, check your focus because your stars were big. Also make sure you aren't dewing up because that will do that too.

It sounds like I may need to focus on nebulas until I can rethink my filter setup for galaxies.

When imaging galaxies you are imaging stars (plenty of them ...). Stars are emitting light in the full spectrum (with some absorption lines). Therefore you want to use R, G, B and L for these targets. Wether it's worth to use H alpha in addition depends on the galaxy. Since galaxies are far apart it's usually not worth to use Sulfur or Oxygen filters. In contrast to hydrogen these elements are rare and when you are imaging a galaxy you usually only capture the red and blue parts of the spectrum of the stars in the galaxy with these filters.

Clear skies
Wolfgang

Makes sense. May need to get a 7-filter wheel.

Andy Wray:

Andy Wray:
My question would be: why are you trying to image M31 in SHO?  I would image it in RGB and maybe enhance it with some Ha data.  I did try to use your SHO data, but it was very lacklustre compared to an RGB version.

Thanks for trying. My camera is mono with SHO narrowband filters. So at this point I’m shooting SHO.

I also use a mono camera, however I have 7 filters:  Lum, Red, Green, Blue, Ha, Oiii and Sii.  This is a fairly usual setup.  For galaxies it is mainly LRGB with some Ha data and for nebulas it would be Ha, Oiii and Sii for the nebulas with RGB for the stars.  Any reason why you are limiting yourself to SHO?

Definitely need to get into LRGB. With the 183GT I only have 5 slots so I’m not looking forward to frequently swapping SHO for LRGB.

This may be a silly question, but can I stack filter wheels?

This depends mainly on two things:
a) Does your software support two filter wheels? 
b) Is there enough space in your imaging train to still keep the proper backfocus distance with two filter wheels?
The third question whether it is possible to couple the ASI183GT to another filter wheel should be solvable somehow, although the approaches may be restricted by question b).

Looking at your images I saw that you used your Canon 6d for imaging. So why not use it for your RGB images? You could enhance the images with the luminance channel from your mono camera. If you register your 6d images to the luminance images of the 183GT the stacking software should take care about the different crop factors.

Just an idea. Depending on your budget buying an OSC astrocam for RGB could be another approach.

Clear skies
Wolfgang