Question: When Should I Use A Tripod?
Answer: WHENEVER POSSIBLE. There. Said it. From this moment on, no matter what, you must remember to use a tripod on nearly every possible situation.
The tripod is indispensable to any photographer (pro or amateur) who respects itself. People who don't use tripods often use the following excuses to justify themselves:
1- They are Heavy/Bulky/Unpractical.
2- They are expensive
3- I don't need them
If you've used any of the above, you are horribly wrong. Here are counterpoints for those excuses:
1-Pro tripods ARE sometimes bulky, and heavy, but this has a basic reason: The more bulky a tripod is, the lose movement it'll have. Weight creates stability. Few things can move a bulky tripod. But that's only on Pro tripods. Amateur (or perhaps "Semi-Pro") tripods can be quite the light equipment, some of them being just 1 pound. And then of course, there's mini-pods, like the Gorillapod, a magnificent piece of equipment that, literally, can wrap its legs around any surface. Minipods are not Pro-Equipment, but for soccer-parent photography, it's a really good product.
Mind you, tripods are not, and shall never be, unpractical. The results achieved when using a tripod will prove this to you
2- It's true: good tripods are expensive. But good tripods, when used properly and taken care of, last forever. If you buy a good tripod today, you will be able to use it 20 years from now.
Good tripods are like good pictures: 20 years from now, you'll be glad to have them with you.
3- "Why use a tripod, when I can squeeze my body pretty tight, and obtain the maximum stability?" "I don't need a tripod, I've ISO 3200"
It doesn't matter! Even if you have ISO 3200, or if you normally shoot at 1/500 of a second, the tripod shall give you sharp images, almost 100% guaranteed. Of course, tripods are not magical. You need to make sure all screws are tightened up. But the next time you say "I don't feel like taking out my tripod", take it out. Then take 2 pictures, one with the tripod, one handheld. Then, check the pictures on your computer. Close up on a point, any point, and you'll see why cool people use tripods.
Of course, there's the tripod's cousin, the Monopod/Unipod. A Monopod may weigh only about a pound, occupies about a tenth of the space of the tripod, and provides good stabilization. And they make for amazing walking sticks. But consider it as an alternative, for use on hiking trips, and crowded stadiums. A Monopod lacks the stabilization of a good tripod, and althought it will make for good, sharp pictures, tripods are still tripods.