A couple of nights ago as I was going to sleep I thought of a way to do this and thought to myself I'll try that tomorrow and as most things you think of at night I forgot it, but last night I remembered it and WROTE IT DOWN.
I know Photoshop cs2 and 3 have this function, not sure on the others.
I've used Photomerge to create widefield images before and I thought what if I chuck some astroshots in there how would it handle it, The answer is quite well, I just through some test shots in and it did a fairly good job, a few images where slightly off but a little correction soon fixed that up,
To do this either open up the images or just skip that part,
go to File > automate > Photomerge
for layout choose reposition only and MAKE SURE YOU UNCHECK BLEND IMAGES (this will crop the images)
choose your files and click ok,
let it do it's thing and done.
It's not quite as good as other software but with a little fine tuning of the images it will be spot on, This will save me a hell of a lot a time doing it manually.
Oh yeah forgot to mention though you have to set your own opacity and blending options to remove the noise, I find if I group 2 layers with the bottom one with 100% and the top one 50% opacity and merge the together this yield the best resualts
eg: merge layers 1-2, 3-4, 5-6, 7-8.
the repeat the process till I have one layer left
and here is the first test shot I have done with this method
It should work nicely in CS2! I have CS3 and I'm just not sure if you are aware that CS3 will align images for stacking via the following procedure:
File, Scripts, Load Files to Stack...
It has an option to Attempt to Automatically Align Source Images as well.
Once the stack is built, of course, you then go through and set your blending modes.
To stack all your images at once, set the opacity of each layer to 1/n, where n is the number of the layer. That is, the background layer is layer is n=1 so 1/1=100% opacity, 1/2=50%,1/3=33%, 1/4=25%, etc.
I just ran both ways through the same images they are very close to being the same but I think with these images that I used, photomerge has the best results.
I used both methods and used lighten blending changes on each layer to show the stars location for each frame on every layer, the full size images showed very little difference, only zoomed in did I notice that photomerge has the edge over the script way.
here the final image though I might do a little more testing.
The left is photomerge and right is the script method.
