Thanks so much, Michael. I am still finding out a few things about Elements. I am impressed with the fairly simple stacking program, designed to allow you to make a panorama. I use it not for panoramas but to combine images. It's especially good with the invertebrate fossils I collect. If you're lucky when you split the shale, you get a part and counterpart fossil -- one on each side of the rock. Then I just scan in the pieces with my scanner, using high resolution. I flip one of them so that they are no longer mirror images. Then I work to get them aligned the same way, such as turning one so many degrees to the right. Then I run the panorama program. It almost never aligns them on its own, but it allows you to drag the images onto a square where you can do your own alignment. Then it puts them together as a single image. The result: parts of the fossil may be missing on one rock piece but on the other. This combines them to give a better look at the animal. I think the same kind of process could be used to combine astrophotos. This is a really nice program. Thanks, Joe