For the amusement/edification of all large formatters.
Having recently spent most of my available cash putting together the lightest field camera outfit I could devise, I was left with the problem of making a focusing hood alternative to the black T shirt. I had been looking at a Linhof accessory made for 6x9 cameras that looka bit like a bag bellows with a focusing magnifier in one end. However I couldn't find a 5x4 equivalent in my price bracket.
It was whilst browsing the usual round of charity shops (yes I am a cheapskate) that I discoverd a large black beret which sparked the germ of an idea. After exchanging one pound for said article, I cut a hole in the crown into which I stitched an old filter ring to which was then bound some thin scrap leather. Into the head band I threaded some wire to which a couple of laces were attached at either end. These were to attach the hood firmly to the camera in windy weather although I have not needed this precaution yet.
The result is not perfect but it's not bad either; more skilled hands would make a better job I'm sure. I can fit a magnifying loupe through the viewing hole if need be. There is also just about enough flexibility to allow me to see all four corners although the hood can become detached if not careful.