How nice it would be if you can just make the type a bit narrower

How nice it would be if you can just make the type a bit narrower

I like the tight linespacing with LTR Principia. The text in white is at width 80, the author is set in width 52. John Gay is the photographer in the original edition of this book and I wanted to include a small byline. However, the photos on these covers are mine, took them on a recent trip.