I have a question - why is it that when I set up a slideshow of a holiday trip, with photos and videos, and finally play the slideshow, the videos are not played at full frame ie. the size of the video displayed does not fill the screen like the photos do. Even after selecting Zoom to fill frame, there is no change. Any help? Many thanks. I have quite a lot of videos to slideshow in addition to photos!!
Which version of Lightroom are you using? I am not able to reproduce this issue on a Windows computer, What is your operating system?