Yes, as bluetone says, your transparency map in the blender channel (either still or movie) needs to be black and white with no shades of gray. That means that any lossy compression formats will tend to make the edges of your leaves fuzzy. Sequenced bmp or tiff would be the best method. In theory you can load sequenced images (numbered image000000.bmp, image000001.bmp, etc.) as a shader texture map and it will run as a movie but there appears to be a bug in C3 that stops this working so load as an uncompressed avi (or similar) instead. I made a sequence of four bitmaps in Photoshop, just black leaves on a white background moving up and down and (using C2) loaded them successfully as the transparency blender into a shader, with just green for the colour. I applied this to a vertical plane to see the effect and it worked quite nicely. Glad to be of help. Mark