At our camera club's Practical Evening in a couple of weeks time I am demonstrating resizing images to be used in PDI competitions. With this I have no problem with at all. However, please forgive to what may seem a very basic question, but what are the reasons WHY we need to resize images for PDI competitions? Can a projector not project a full sized image eg 4000x3000. Would the projector not project it at its native resolution? I appreciate that by resizing down to say 1400x1050 you are reducing the file size considerably, but is this the only reason? Apologies if this seems obvious, but it's often the obvious that you miss.