I shot this test photo some time ago and just ran across it while working on my film archive. My son Adam posed for me so that I could test some Kodak Porta 160VC film and the tilt function of my Toyo VX-125 4×5 view camera. I tilted the front standard so that the plane of focus ran through his eyes and along his nose, leaving his chest and chin out of focus. I liked how this turned out and have used this tilt technique several times since during portrait sessions.
Below is a graphic showing how tilting the front standard changes the plane of focus. This is called the Scheimplful Rule – a name I can never pronounce and never remember how to spell. But the principal works quite well.