I did a cloud animation and all I got was what appeared to be overexposed clouds and surface. I did a shorter render and the images were assigned an .alpha before the extension, but about half of the frames were regular, non-alpha images. I rendered it again and got one each copies of a regular image in .bmp and a complete set of alpha channel images. I did not change the .%4d.bmp in the "Output image filename" or IMAGETYPE.%4d.bmp in the "Extra output images" dialogue boxes, I only changed the filepath so it didn't dump everything into the same folder for each sequence. Has anyone had a similar experience or am I missing something here. Alpha images are useful in certain instances, but I am only interested in the bitmap images for this project.