South Bound - best advice I can give it to play around! I'm completely self taught and spent the best part of six months shooting in Manual mode in order to fully grasp what was going on.
Have a read of this
http://www.cameraporn.net/2007/12/24...-of-threesome/ It's about the relationship between shutter speed, aperture and ISO and then go out and play around with the settings (it doesn't even have to be away from your own home) to see what effect changing each has. It'll also let you know your own, and your equipment's limitations. I'm fairly stable and smooth with my panning (tracking) of the aircraft, so I can usually get away with fairly slow shutter speeds (which allows you to get a better 'f' number, or use a lower ISO). You may or may not be able to, in which case you'll have to sacrifice a good 'f' number or the ISO.
As Ancient Aviator has eluded to, camera gear is generally one of those 'you get what you pay for' kind of things, but acceptable results are achievable with modest gear, and I'd certainly recommend learning the basics before you go out and spend any serious money. Plenty of people think that will be the answer to their problems, but then still fail to produce the results they expect.
Ancient - no IS or L-series on either of the lenses used here. The only L/IS I own is the Canon 24-105mm
PS all were shot on Tv mode with a shutter speed of either 1/640th or 1/800th. I wouldn't normally shoot that fast, but the proximity to the aircraft meant that in relative terms they were moving rather fast!
