LBN 438 is pretty dim for being on a list of bright nebulae!  In Gary Imm's excellent write  up (https://www.astrobin.com/8iq7ay/) he notes that the object’s surface brightness is magnitude 23.  It sits between three relatively bright stars which are out of my frame here.  But their glow intruded strongly when this was stretched to the degree needed to bring out the fainter parts of the nebula.  Cropping and manual field flattening saved the day.  I found DBE not to work well at removing the out-of-frame star glows as it would also interact with the faint Ha in the background.  

I've called this the Whale Shark since that's what I’ve been seeing in my mind since I started capturing data.  I suspect someone else called it that before but I can't find it searching the web or AB so maybe it was me?  Of course, I also see the maw of the Sand Worm and I'm definitely not the first to see that!  It's quite a Rorchach test this one...

I shot Ha here, primarily to feature the red glows of the mount/maw.  But this also picked up a very faint Hydrogen glow in the background on the left.  Others with faster systems and darker sites have captured that better.  But I liked the complexity it added to the image so I tried to keep it.  

The Ha was cleaned of continuum, star remnants removed, and then added in a linear state to the still linear Red channel of color calibrated RGB.  Because I removed the continuum and the backgrouind pedestal of the Ha first, I was only adding an ADU or two and so it only bumped up the red rathher than unbalancing the colors.

Before creating the RGB master I did a linear fit of the R,G, and B masters to the Luminance master.  This made it easier to color balance and to add the L to the RGB without washing out the color.  I'm finding that little Linear Fit stretch helpful in many ways, including avoiding posterization when doing linear noise reduction. 

Stretching was done with a masked stretch first and then GLS.   This kept the stars in check while I tried to separate the dusty nebula from the background.  In PS, stars were masked during some of the curves adjustments.  The star mask came from StarXterminator.  Not sure I remember how to process without Russ Croman's excellent tools