I am doing asteroid photometry work in which one step with MaxIm is to align the images. After doing a plate solve, the software does a nice job registering the stars. After alignment, some of the images show the checkerboard pattern, as in the example below. Note that this is a pretty extreme stretch. The graph of the pixel value for the line I drew doesn't show much waviness, so perhaps I shouldn't worry about it. Still, I'm curious if anybody knows what is going on to create the pattern, and if there might be a way to eliminate it. Thanks. Tom
No, it's a monochrome STXL-6303 camera. Let me try the same thing using images only east or west of the meridian, and see if the meridian flip has something to do with it.
If you are not at 100% zoom, you may be seeing an aliasing effect between the crude pixel-dropping method that Windows uses, against a very subtle pattern caused by the interpolation algorithm. Which interpolation method are you using - bilinear or bicubic? See http://www.cyanogen.com/help/maximdl/Align.htm
I am at 100% zoom, and it still shows up. The "Stack" menus have interpolation method choices, but I see "Bicubic" as the only choice for simply aligning images (not stacking). Tom
If you turn off Bicubic, you get Bilinear. Bilinear isn't as "sharp", but is better if you're doing photometry etc. http://www.cyanogen.com/help/maximdl/Align.htm