I downloaded your IRIS image to see what it looked liked...

1) I think you had a fair bit of thin cloud floating through during your imaging session(s)?

2) I reshaped the corner stars in Photoshop. I noticed the bottom two corners had slightly more elongation than the top corners. Due to your cropping or a slight miscollimation of your scope; I can't tell which??

3) I think the various filter stacks were slightly misaligned? I'm saying this because of the color gradients in the dust lanes of the image. It could also be due to different imaging conditions for the various filter sessions? Really hard to tell AND it happens far too often when shooting with a mono camera and filters!

There, I've probably overanalyzed your mono images to the point of you blocking further comments from bwa...

Good points - Not sure about the clouds.... I collimate each time I set up - just a habit before adding my camera - BTW, I had just collimated my collimator ...so I don't think it was that. The cropping could very well be the reason for the bottom having more elongation issues....but suffice it to say the uncropped image is laughable and unusable. You may be spot on regarding the stack alignment issue - these were done using the batch preprocessing script in PixInsight.

PM me with your email address and I will drop the raw processing Ha, Lum, OIII, and SII files in dropbox if you want to play around with them.

bwa

I downloaded your IRIS image to see what it looked liked...

1) I think you had a fair bit of thin cloud floating through during your imaging session(s)?

2) I reshaped the corner stars in Photoshop. I noticed the bottom two corners had slightly more elongation than the top corners. Due to your cropping or a slight miscollimation of your scope; I can't tell which??

3) I think the various filter stacks were slightly misaligned? I'm saying this because of the color gradients in the dust lanes of the image. It could also be due to different imaging conditions for the various filter sessions? Really hard to tell AND it happens far too often when shooting with a mono camera and filters!

There, I've probably overanalyzed your mono images to the point of you blocking further comments from bwa...

bwa

Interestingly enough, I am a huge lightroom fanatic - I have over 1.2 million photos managed by different catalogs (mostly sports) but I have never used LR for any of my astro images. I handle almost everything in PixInsight or PS.

I typically use the batch pre processing script for image registration, calibration and stacking.....I haven't seen any advantage doing this manually. That is probably due to my data.....better data may very well benefit from manually processing.

1) crop using dynamic crop for all images, Ha,OIII,SII,L,R,G,B
2) I take the image with the best signal and use Linear Fit to apply the same exp settings to the other images.
3) I use Channel Combine to produce my RGB image (Ha-Red, OIII-Green, SII-Blue but also change to bicolor, and hubble color)
4)Then I use Channel Extraction to separate the RGB into LAB. I throw away the L channel and then use Channel Combine (in LAB mode) to reassemble (but I use the Lum version that I took...not the one extracted when using Channel Extraction....this gets rid of most noise if present.

Steps 3 and 4 work ok but Pixelmath works just as well faster and easier to experiment with different percentages.

5) I am not a huge fan of DBE....I have yet to see it remove gradients effectively with emission nebulas ....I can do this in PS in two three very easy steps....duplicating the background - removing the bright stars with clone stamp ..some cases patch tool...and gaussian blur at 200 to get rid of the rest - curves to darken that layer, and "Subtraction" blending to remove the gradients.

6) Color Calibrate
7) Histogram Transformation
8) Add Lum Mask and run HDRMultiscale Transform, keep the same mask and run LocalHistogramEqualization
9) Remove that mask and add Star Mask and run MorphologicalTransformation
10) I have been known to run Unsharpmask here but usually reserve in PS if I sharpen at all and do this with luminosity masks applied for selective sharpening - I like to be able to brush it in or out if needed to only the parts of the image where I think it is needed.
11) ACDNR - TVGDnoise on occasion.
12) I sometimes but it's rare run a CurvesTransformation (but If I am planning on taking the image into PS....i leave out this and other steps) Just depends on how much in love I am with the data. If it is so so....I do everything in Pix.
13) Same with Color Saturation.

Because I am a huge fan of luminosity masks for making selective adjustments for tonal, structural, and luminosity changes - I prefer to make these changes in PS.

If the image is loaded with good data I do any noise reduction in PS using (PS plugins) Topaz DeNoise (preferred) or Nik's Define.

I am sure I left out some important steps but I am currently working on another image with better NB colors and these processes are being used now....a big help in jarring my old memory.

What a hobby....I should sell it all and take pics of my grands only :)

Both processed in much the same way:

1) Loaded four stacks into PixInsight
2) Performed MaskedStretch on all stacks
3) StarAligned all stacks
4) Combined using LRGB utility; played with channel settings and saturation
5) Saved result as 16bit TIF file
6) Loaded into Lightroom and adjusted to taste. Remember, I like color and lighter backgrounds.

Comments:
1) I really like the Hercules cluster. Stars a touch out of focus but darn good!
2) Not too sure what is happening in lower left corner of Iris image. Is there a nebula in this region?
3) I did no star reduction or reshaping during processing

Thanks for the datasets. I was getting cabin fever from lack of time under clear skies!!

bwa