Full length portraits

Here is another likely dumb question.

Last weekend, I was shooting some portraits of a friend and wanted to get a full-length shot of him sitting in a chair. His knees and feet were, obviously, closer to the camera, and in the ground glass, they looked disproportiately large. The camera was roughly at eye level (his eyes) and I used a 150mm lens. I made sure the camera was level. I fiddled a bit then gave up and just did head and shoulders.

Has anyone else experienced this? What am I doing wrong?

You could pose the subject at an angle to the camera or step back to get a less exaggerated perspective. You could turn it into more of an environmental portrait, or use a longer lens to keep the tight framing.

If you have the room and the lens, use a longer lens. I use to do full standing portraits for military officers up for promotion (I know, it doesn't match the political statements I've made in the lounge, but I needed the cash). For those shots, I would use a 120 or 150mm and put the camera around shoulder height. The highlights on the spit-polished shoes, the crease in the slacks, the metals, the eyes and the chin all had to be in focus. It was not art.

I would pick the one feature that tells the story about your subject and diminish everything else. If the feet aren't what defines this person, but you want them in the composition, you can throw them in shadow, or thow them out of focus (or both). You might also want to try another angle where the feet and legs aren't out front. Raising the camera slightly will move the feet farther away, relative to the face.

Shorter lenses make objects closer to the lens appear relatively larger than other objects in the image. This is not due to the lens itself but the distance of the lens from the subject.

A longer lens, 210-300 will help if you have the space to move back.

just back up or use it as a cool effect... a 150 is great for full length