Update 1/2/2022:
Nothing more done here other than apply the star correction on the completely processed image to fix corner stars because of tilt and backfocus issues.

Update 12/11/2022: 
This revision is a complete revision of the original using my current process flow in PixInsight.  This is a continuation of my working through my older images using this new process.  Simplicity per the benefit of StarXTerminator, NoiseXTerminator and its detail enhancement feature.  This all helped by the improved batch preprocessing.  Issues improved upon is a greatly reduced larger scale noise.  Stars are reduced in bloat even though I kept the stars at about the same level of number and intensity.  Contrast and fine detail is improved with probably better image accuracy.  Better stretching (not using any different stretch algorithms at this time) allows for better visualization of the fainter IFN signals.  Most all of the improvements can be nicely seen if you go to the region of, and within, the "whale's" tail and look at the details lost to the larger-scale noise and softness in my original image vs. the new.   Also, by choice, I boosted the signal of the HII regions, to include the faint red hues throughout the image.  Really, there is no part of this frame that does not have HII signal, though most people choose (as I did) to bring the black point up in some of the areas to create some dynamics between the brighter HII structures and the dark of space, especially since some of these regions have galaxies present.  So I cannot argue with the logic to create a darker black point, but I already did that in my original post and I also lost a lot of the faint IFN.  Choices, choices!

I love the images that I have seen of the field.  But to me the most impressive images of this are the much more widefield images that include the whole of SH2-126, extending well below this field.  I hope to come back some day and create a widefield mosaic image of all of that with this included.  Given the efficiency of the RASA 11, this should not be too much of a burden.

Original Description:

Well considering that @Konstantin Firsov  just published his wonderful IOTD rendition of this very same subject, I kind of feel like I showed up at the ball with the same dress as the host!  Nevertheless, this little cloud caught my eye earlier this month while surveying Aladin for something to capture during a lucky hole in the clouds.  I figured that the signal was good enough to capture in the ~3.5 hr I could devote to it with my OSC camera.  Unknown to me, but with hope, was if I could also see the faint velvet red from Sh2-126.  I was pleasantly surprised.  I think Konstantin's wider field of view does better justice to the target overall.  

Sh2-126 continues as a much larger nebula of Ha emission that resembles a draped velvet curtain.  I will have to come back one day with a wider field to capture the whole of this and include Ha data.

LBN 437 is the densest knot of dust in a region with other more scattered such clouds that all seem to be related.  I would like to speculate that from this image, and others that I have seen, that LBN 437 is in the foreground and removed from Sh2-126.  It is claimed that the star 10 Lacerta (well outside the frame of this shot) is the culprit with respect to the ionization of the hydrogen in 126.  But 437 is not so far removed that it completely escapes the intense UV from either 10 Lac or possibly 8 Lac.  I say this because there is a bit of red emission obvious around the lower portion of the densest parts of 437.  It may be that the difference in emissions is due to location differences between 126 and 437 relative to the UV source.  On the other hand, 437 is morphologically different than 126 and may well be compositionally different as well.  437, in its densest portion, is a bona fide star forming region.  There is clearly a strong reflection nebula from a partially buried star.  This is a young Ae/Be star, like that found in the Iris Nebula.  There are also buried HH objects in a line to the right of the reflection nebula that I have not seen in any vis imagery.  Because 437 is star-forming in nature, it likely contains significant dust, a necessary component in the modern era of star formation to allow clouds to cool and thereby condense gravitationally into stars.  This dust may well partially intercept the UV from 10 Lac, thereby preventing enough penetration of the UV light to cause Ha excitation in any areas of the cloud except right near the edges as can be seen here.

Sh2-126 looks very different.  Very smooth.  Anything but clumpy!  I suspect that Sh2-126 is a much thinner gas cloud with much lower fraction of dust.  It could be argued that we only see the illuminated face of a much larger gas/dust cloud, but the fact that we can see distant galaxies right through the red emissions suggest that this is indeed a very thin veil of gas.

I struggled with stars in this rendition.  Certainly a did a lot of star reduction to enhance the view of the clouds.  But this time, I seem to have created more artifacts than I am comfortable with.  So I may come back to improve this.  I think that with my rig, 3.35 hrs is sufficient time for this subject.  So if I put more time here, it will be to get the totality of Sh2-126, which will include this gem.