It sounds like you need a cardioid mic (picks up what the mic is pointed to and some from the sides, and less from behind). A standard shotgun will reject sound from the side, although there are short shotguns like the Sennheiser MKH 8060 that have a somewhat broader pickup pattern. In your case you want broad, since you're not trying to pick out individual dialog from surrounding sounds. Note that you can't entirely eliminate noise from the rear; shotguns are better at this than standard cardioids (the only mic I know of that's able to magically block virtually all sound from the rear is the $2,500 Earthworks SV33 but that's really a studio mic).
You'll want a condenser mic instead of dynamic, because condenser mics are more sensitive and for the big distances you're trying to cover you'll need sensitivity. The downsides of condensers are the need for power (battery or external 48volt phantom) and more sensitivity to humidity (although some use circuitry to minimize this), wind, and handling noise.
Picking up everything from one end of a field to another is a tall order for any microphone, but if you're just trying to capture ambient sound you might be able to do it with a semi-wide cardioid. There's no such thing as a "telephoto mic" although you could do some research on parabolic reflectors to see if that would be a solution for your needs. Edited to add, you could also look into binaural microphones like this one:
https://www.soundprofessionals.com//cgi ... m/MS-TFB-2A few other considerations to think about:
1. Inputs matter: See
http://www.shure.com/americas/support/f ... -camcorder for more details.
2. Preamp quality matters. Especially when you're trying to pick up distant sounds, you don't want to have to deal with noisy preamps on top of it. You have to factor the microphone's internal noise into the equation as well. You'll want a low-noise preamp and a low-noise mic so you can boost the levels in post-processing without hearing hiss.
3. Wind protection is important. Most cardiod condenser mics are sensitive to wind and handling noise and at the very least you'll need a "dead cat" windscreen and better yet a blimp plus furry windscreen. The foam windscreens that come with many mics are for use indoors; they won't do much to cut wind outside.