Photomerge won't merge my pictures

[VinnieM0nster]

Hi all,

I've recently taken some shots of the Pleiades using my SkyWatcher 200 PDS with skywatcher 2" coma corrector on my Nikon D5200. I couldn't fit the whole of the thing in one shot so I shot 3 sets of panes.

However, when I try to stitch them together in Photoshop it won't take the pictures. When I overlay them using lighten layers, most of the stars won't line up because of an obvious issue with coma warping (not sure if that's a term).

What can I do to make all of the stars fit on top of each other? I tried transforming the layers but it is such a hard job I gave up after an hour or so. Has anyone else got this issue? Got a quick fix? :-)

Thanks for reading and clear skies :-)

Vinnie

[Landbo]

Hi Vinnie.

Try Microsoft's ICE software. It works great, also on pictures with a non flat image field, and is so simple that a 7 year-old child can use it.

Link to ICE: http://research.microsoft.com/en-us/um/redmond/projects/ice/

Regards Leif.

[VinnieM0nster]

Thank you Leif, I will give that a go tonight!

[VinnieM0nster]

Just wanted to report back that ICE did eventually did (part of) the job. It managed to stitch together two of the three images I had, then in Photoshop blended them together using the lighten blend mode. I've attached the result. Next time, I'm definitely going to try and take better shots. First time for everything though

[Bizibilder]

How much overlap did you have between panes?  Often you need at least 30% for the software to make a good job of it.  I have found the PS does need a "good match" or it will reject panes - even with a good overlap!.

[VinnieM0nster]

How much overlap did you have between panes?  Often you need at least 30% for the software to make a good job of it.  I have found the PS does need a "good match" or it will reject panes - even with a good overlap!.

Probably about 30% actually. But I do see why it didn't want to take it, there was only 1 bright star overlapping between the top-left and the middle pane. The only star that was present in all three panes was the one with the little trapezium of stars next to it (sorry I don't know their names). 

It's good to know that you do need some serious overlap, this will help me plan for future sessions!

Thanks for the comments everyone.

Vinnie