I have been shooting 4 x 5 color transparencies or commonly known as color slide film for many years but the best that I could enjoy them was to put them on the light table and viewing them through a loupe. Unlike my 35mm and 120 slides, I have never seen them projected big simply it is not easy to locate a 4×5 slide projector.
For the last few years, I tried searching online on how to do it yourself (DIY) and build a 4x 5 slide projector but no one seems to have made them before. There are commercially produced 4×5 slide projectors although I have never seen one in real life. I have not even seen them on the used market on eBay before but even if they are available they are going to cost a lot and even more to ship.