unzipped, In photography, 100mm is considered 'better' for head shots and portraits. Longer (telephoto) lenses flatten perspective slightly, and short (wide-angle) lenses exaggerate it. What happens is this. When you frame someone's head with a longer lens, you're standing further away from them. With a short lens, to get the same framing, you have to go up very close to them, and the exaggerated perspective makes their nose look big, etc. You can frame a head with a 100mm lens from 6 feet away. With a 24mm wide-angle, you'd be 1 foot away. That's the 'science' of it, but it's really just common sense. I've been a fashion photographer for 20 years, so it's my job to know this stuff. But as I said up above, you need to know the rules so you can break them. Here's an example you'll recognise. Practically every rap singer used to get photographed in the same way - with a wide-angle lens, hands into the camera, and wildly exaggerated perspective. Dunno how this look came about, but it caught on. Well, that's an example of breaking the rules. But, if you ever try doing a portrait with a 20mm lens, you'll find out that it's not so easy. (For a start, you're so close that your own shadow falls on the subject, so you have be good with lighting). Once you know what you're doing and why it works, you can go your own way. mac