In Slideshow, the image in the Template Preview correctly zooms to Fit, but when you Play the slideshow, or export the video, the image reflecst the original image size. The only way to fix this is to open each image in PhotoShop, manually change the image size, and then resave the image back into Lightroom. This is extremely tedious and timeconsuming when you have 100's of images in a slideshow. A much better approach would be to have a "Check Box" in the Layout section that will automatically resize/zoom the image to Fit the screen in Play mode.