Align 10 astro photos by hand

[pedzsan]

I have 10 photos that were shot roughly 2 seconds apart (with a 2 second shutter) that I want to align.  Lightroom loads them up as 10 layers in Photoshop.

When I try to use auto-align, I get some message about 40% overlap.  These photos are 100% overlap but they are just stars and I guess the algorithm doesn't work.  Fine.

So, I unclicked the eye on the top 8 layers and put a 50% grey mask on the 9th layer and take the move tool (turn off snap), zoon in, and align it by hand.  The problem is there might be not just an x-y movement needed but a rotate as well.  So what I thought would be nice if I could align the top right corner and then "put a thumb tac" in it (a pivot point), then go to the bottom left corner and rotate the 9th layer about the "thumb tac" to align the bottom left.

Then turn off the eye on the 9th layer, turn it on on the 8th layer, move the 50% grey mask up, and rinse and repeat.

But I don't know how to put a "thumb tac" or a pivot point or even how to rotate via the move tool.  So... I thought I would come here and ask.  Perhaps there are better alternatives to the approach I am taking.

[pedzsan · Accepted solution]

My son showed me how.  Align the first star in (e.g.) the upper left corner with the move tool.  Then Edit => Transform => Rotate, position the reference point on the first star.  I did this by clicking the upper left corner of the icon in the tool bar which got the reference point close and then dragged it over the star I had just aligned.  Then go to the opposite corner (bottom right) and rotate until the stars match up.  Wasn't too painful doing it 9 times.