well, don't really know, basically, i just wanted to learn how to do one, i looked at the TTL example long time ago, it didn't really seem to work well. now, just about an hour after I first posted this, my photoshop takes a dump on me! I was just trying to learn how to do it, basically looking for the proper sizes of the image before I do the polar adjustments, what i do know is that the image needs to be equal height and length.