Orion is now gone in the west and before I lost any chance of one last imaging session with M42, I wanted to complete a fun little project.  We all look at the gorgeous DSO images members post on Astrobin,  but how often do we stop to think about how the stars are really placed in space?  What looks very flat in an image may be anything but in 3-dimensional space.  It is quite interesting to visualize what the distances to stars in nebulae and even constellations really look like.  So, going forward with what my collaborator @Christoph Lichtblau and I did with the stereogram of the terrifying bat and had so much fun interacting with members about the 3D rendering, I set out to demonstrate 3D views of stars of interest in space.  Using my 215 mm FL guide scope as a main imaging scope, I took 125 4s subs and 92 8s subs of M42 low in the western skies just after twilight.  The guide scope is not optically superior to say the least, but it gave me what I needed for the project. 

First, I prepared a stereogram of the result from stacking and processing the M42 subs into a final image.  I used Stellarium to look up distances to the major stars in the field as well as M42 and the Running Man nebula so that I could shift them in one of the images in the stereographic pair such that the objects' relative distances would be visible through the 3D effect.  This did produce some surprises!  For example, in the Running Man Nebula there are two brighter stars nestled at the left edge.  But in reality, these stars are much closer by different amounts than the nebulosity itself.  You can see this quite easily in Revision C. 

Next, I wanted to do the same kind of thing on a larger scale, so I took a screenshot of the body of Orion in Stellarium (no arms, club or shield) and thus acquired a star field.  I then digitally cut out the images of M42 and the Running Man nebula from the main image posted here, shrunk them down to scale and placed them in the star field to create a wide field image of Orion. I did the same with one of my previous mages of the Horsehead and Flame Nebulae complex.  The Witch Head Nebula in the field, however, is courtesy of Stellarium.  Lastly, I looked up the  distances for as many stars as I could as well as the nebulae and prepared a to-scale 3D stereogram, which is shown in Revision D.  I hope you can see the 3D effect and have fun looking at where the stars and nebulae really lie relative to one another in 3D space.  Of note is how much farther away the center star in Orion's belt lies from the other two as well as how the Witch Head nebula is quite closer than the other nebulae in the view and M42/Running Man and Flame/Horsehead lie well beyond the two outer stars of the belt.

I did my best to make the 3D effects mathematically accurate, but for fainter stars I couldn't find distances easily enough to mess with all of them.  There also may be some modest error in placements of things, so I apologize in advance if it isn't perfect!