Writing the movie to disk and then using ImageMagick was several times slower - it also took significant disk space and memory. Which my old laptop couldn't cope with. I used several different methods - blends, composites, averaging - try them all and see what you like the look of best. There wasn't any significant difference using every frame rather than every 25th - and it ran a lot quicker. Can't wait to see what you create with it 🙂