My x5 zoom buffer is bigger than 413 lines. But there's a problem. Any movement at all divides the image into 2 pieces that don't match up. Like they are cut horizontally and not lined up. You can guess how this happened. The top half was one scan of the sensor, the bottom half the previous one. Rarely the line is near the bottom or top. Even with zero movement there is a difference in exposure that you can see above and below the line if it's in the sky. That was the 616 line buffer from coutts build. Oh well back to the drawing board.