Yeah the EdgeHD 11" would be very nice to have. Nice deal on the Astrotracker, I know a few people that have imaged with it, definitely very capable for that price. Any tracking at all is a huge improvement over a regular tripod. Should be able to play around with that long enough and get used to it till you get the EdgeHD. Maybe even learn some handy things along the way.
Aye. Hands on experience is a necessity at some point. I had hoped to start getting hands on tracking experience months ago, but alas, things changed. And as you say, any tracking is a huge plus. I am also curious if I'll be able to figure out a way to mount my 600mm lens and camera directly to the equatorial mount. I am not sure if it will take the weight, which would be around 12 pounds I guess. With a 2x TC, I have a 1200mm "telescope", and with both TCs it is 1680mm. That is pretty decent for planetary photography!
So although it is not a perfect experiment, I took some shots before it was perfectly dark. I tried the linear dodge add method and the mean method as you have outlined. I think they pretty much end up doing the same thing although you have different results to do your final adjustments with. I tried to do minor post production and have them appear as similar as possible although I did not do that great of a job and did not really focus on making them pretty or anything, but I think it gives the general idea. With enough tweaking I think they would be pretty much identical. I will say that I find the linear dodge work flow a little easier than all the switching around with smart layers and stacks. after alignment you just select all the layers and change it to linear dodge add and then convert to to 16bit. But that may just be my personal preference. I am glad I tried the mean method though, it is always neat to see the different ways of doing something
The first one is linear dodge and the second is the mean.
Camera: 50D Full Spectrum modified
Focal Length: 400mm
Stack of 20
Thanks for the test. Very interesting results. From a noise standpoint, they do indeed look identical. From a color standpoint, colors are a touch richer with the Median method, and stars are just a little softer, too.
The Linear Dodge Add method definitely sounds simpler. I'm going to give that a try now, with the previous photo I posted above, and see how things look. I think I may also try photographing the nebula with my 600mm lens for 1-2 seconds and stack em, see how things turn out. I figure downsampling for web should take care of a lot of the trailing.