[cconstantine]

Thanks! I hadn't gotten to writing this out, but you've pretty much nailed it.

> They most likely used a secondary camera whose sole purpose is to guide the mount and keep it pointed at the target object.

I did use a guide camera with an off-axis guider, I'm not sure why it wasn't in the equipment list. I've added it.

> The RGB filters were presumably for the star colors and to incorporate the blue from Alnitak into the image.

This is primarily an RGB image, so the RGB filters were used for more than the star colors. This is a proper true color image. I could get away with doing that from my location because this target is so bright. The HA filter was used as a luminance/detail layer. That gave me a bunch of detail that my local light pollution would hide, and let me pick up on that really wispy stuff in the upper right :)

> The processing here was really tasteful in my opinion.

Awe shucks, thanks :blush:

[seabass]

Ah, of course it's HaRGB. Really cool. I'm curious, you de-star the color layers or leave them as is when combining channels? When I've tried HaRGB, the Ha layer has the best/smallest stars which means that the RGB color layers end up leaving rings of color on the background around each star.

[cconstantine]

I don't remember exactly what I did, but I do remember running into that kind of problem. I probably used starnet2 to remove stars before doing much processing, and recombining stars towards the end.