Star Trail Help?

[jaketravers]

Hello everyone,
I have a dilemma, I've been experimenting with star trail photography and have been using 20 30 second exposures and have been stacking them with Dr. Brown's Stack-o-matic. Both times I have been setting the stack mode to "maximum". The first photo is with autoalign on and the second photo is without autoalign. How do i get the star trails to line up when using autoalign and when not using autoalign how do I get it so there are no breaks in the star trails? Thanks in advance for any help/suggestions.
Here are the photos:
With auto-align
Startrailfail | Flickr - Photo Sharing!
without auto-align
FailedStarTrail2 | Flickr - Photo Sharing!

 

[Garbz]

The problem with aligning in your images is that the software looks like it's picking the lights on the land as stars. Otherwise aligning should work just fine automatically.

The problem with the non-aligning image is the "off" time on your camera. If you're making 30 seconds exposures make sure there's no more than a 5second gap between images. This will reduce the gap between the star trails. Ultimately though if you blow up images at 100% it will still look like there's gaps. But in a reasonable size the gaps won't be visible, like in this picture: http://farm2.static.flickr.com/1353/773160897_fae20200db_b.jpg

 

[jaketravers]

The problem with aligning in your images is that the software looks like it's picking the lights on the land as stars. Otherwise aligning should work just fine automatically.

The problem with the non-aligning image is the "off" time on your camera. If you're making 30 seconds exposures make sure there's no more than a 5second gap between images. This will reduce the gap between the star trails. Ultimately though if you blow up images at 100% it will still look like there's gaps. But in a reasonable size the gaps won't be visible, like in this picture: http://farm2.static.flickr.com/1353/773160897_fae20200db_b.jpg

Thank you very much for the tips. Is there any program that wouldn't see the lights on land as stars?

 

[McNugget801]

startrails.exe

 

[Garbz]

Personally I would run a photoshop batch operation to crop out the bottom and then do the stacking operation. It's not like the bottom benefits from stacking.