Can I auto-align stars in animation?

[michaelmorris]

I've finally getting around to processing a series of asteroid shots I took last year.  I took sets of 20 x 90 second shots, each set being 6 days apart.  This was repeated on 5 different target. I've stacked each series of shots in DSS.  However, the orientation of each nights shots don't exactly line up. Unfortunately the second night's shots were also slightly out of focus, so the image scale is ever so slightly different.  This means that whilst it's relatively easy to rotate and shift the second night's processed image to roughly align with the first night's image, it is much more problematic trying to get all the stars to line up on an animations (see GIF file below).  Is there a way to get the stars in each image to automatically align with each other?  (I would prefer to be able to do this without having to buy any new software - I have Photoshop CS5).

Thanks

[Bizibilder]

There is a way of doing this in Deep Sky Stacker - you do the align and then save the frames "aligned" but not stacked.  Close DSS and reopen the frames in PS and they are aligned for you ready to put one on top of the other in layers.  I'll need to have a rummage through the forum but it is on here somewhere!

[Bizibilder]

Here it is:  http://www.lightvortexastronomy.com/2013/01/tutorial-calibration-registering-and.html  About 1/2 of the way down the page - Step 4.1

[michaelmorris]

Thanks Roger

The tutorial is excellent. I've tried and I think it's definitely better than my manual and auto-align layers attempts in Photoshop.

Manual alignment in PS

DSS alignment

What do you think?

[Bizibilder]

Looks much better - try a 0.5s (or slightly less) blink time and the image should really come alive!

[michaelmorris]

After a bit of experimenting I decided to select the 'Intersection mode' in 'Stacking Parameters' in DSS.  This way both images have exactly the same size, shape and field of view. It makes life a bit easier.  Anyway, below is the (hopefully) the finished article.  Four more to go.

Thanks for your help