Can someone explain to me, in plain english, the real-world difference between .4, .7,.5 etc etc wide angle lenses? Which give a larger field of view, which tends to 'bend' more, etc etc. Thanks in advance :-)
-Chris Rex
http://www.chrisrex.com

To sum it up super simply, the lower the number, the wider the view, but also the greater the chance of distortion (bend). It also has a lot to do with the quality of the lens/glass.

Adrian is 'spot on' with this description.

Bottom line is that 'all' lenses distort at the edges. The way around this is 'don't use the edges'. Easy to do in still photos where you can crop, et al. but hard to live with in video. Suggest that you apply a bit of zoom when using a wide angle lense which will keep you more to the center of the lense and never back all the way out unless you have to (or that is the effect you are trying to achieve).

Part of the 'movie look' that people are trying to achieve is because of the edge distortion. Suggest you try a, say .7 wideangle... slap it into 16:9 and shoot a few minutes. It is interesting..

Have fun!