File size is too large when shared as mp4 video
I have created a 5min slideshow with photos and a sound track that contains both music and voice narration. I want to enter this programme into a competition that requires all programmes to be played on Windows. This means sharing the programme to mp4 video. But one of the other requirements is that the total file size is no more than 500MB. When shared as mp4 my file size is just under 800MB. I have tried down sizing the images but that appears to have no effect.
Any suggestions about how to solve this please.
If it not possible to solve it I would like to know so I can contact the organisers.