If your wanting to catch a UFO, 'chance' favors the prepared person.

Really any camera with you is better than none. Since many don't like to drag a tripod, then use the hood of your car, or a wall, a boulder, a tree, anything but holding the camera free-handed. You might be able to get by for a full-wide shot free-handed, but once you start to use a zoom or telephoto your going to be more than disappointed with your shot. And here's a news bulletin, you'll probably only get one chance to get the shot, so make it count in having a steady support. If your shooting at night, expect your auto-focus to go nuts trying to focus in on your target, you'd do better in manual mode. Someone suggested just 'push' up the ISO, although that may have some benefits, most cameras as soon as you get past 200 or 400 ISO, your shots become noisy as hell with grain.. So it's a trade off.

The above being for the casual user, on the flip side, if one is to assume that your really 'serious' about going out to hunt UFO's, then having one camera, just won't cut it. Again chance favors the "prepared person". All too many times there have been reports that with the sighting of a "real" unknown aerial aircraft, electronics are affected. I personally have had this happen to me twice. On the advice of a former NASA scientist (many years back), I started taking along with me also a older type camera that is truly manual in the full sense of the word. It has no batteries to be drained or electronics to malfunction and is loaded with high speed B&W film.

Many UFO Hunters like using Infrared gathering cameras and/or devices that can be attached to a recording medium. There are pros and cons with IR, I personally bring my IR Cameras with me, and have them set up side by side to my camcorders so that I can get both views/aspects of what is being captured.

Also believe it or not, you want to bring a notepad with you and document as much information immediately after an event has happened. The reason being is that the sooner you 'jot' it down, the less time your mind has to either forget it, or transpose it. Transpose it? Yes, your mind wants to try and make sense of what it's experienced and then rationalize it into a series of logical segments. The sad note is that the events themselves are not usually the type of event that falls under logical in the aspects of what we consider the norm. Also if there are more than one witness, having a written record from each individual can be very incitefull as one may have caught something that you (or others) did not. Give as much information as you can concerning the event. Where you were at, location of the object(s), the time of the event, how long the event lasted, the speed, trajectory, etc., the more information you provide the better. There is no such thing as too much information when it comes to an event. And it adds credibility to your sighting. To simply 'capture' an event with a camera really does not help anyone in the UFO field, you need the additional information to make it a credible sighting.

Just tossing a few tips out there..
Johnny