I'm looking over the next few months to get a lens, preferably a prime, to use for group shots - for example large wedding groups, small family groups - maybe even the occasional school class or work group. I'm on a 20D - therefore 1.6x crop factor. My widest lens currently a sigma 28-200 zoom, with only OK image quality, which came from an old film EOS (and frequently gives Err 99 when I use it with my 20D ... grrr!). My normal walkaround lens is the 50mm 1.8 (love the image quality). You'll guess correctly from this that I love primes and that budget is important to me! A lens which can also perform well for landscapes would be a bonus. Mostly I'm asking what focal length people find works for group shots... Because of budget, I'm considering Canon's 28mm 2.8, but I'm not sure if this is wide enough.