Now that you have your camera ready, you need a way to get it up in the air. There are 4 options I�m going to chat about: hot air balloons, hydrogen balloons, helium balloons and kites.
Hot Air Balloons: There are two types of hot air balloons: solar heated and combustion heated. The solar balloons rely on the solar radiation from the sun to heat the air inside the balloon. Believe it or not, they actually work; in fact they can be big enough to lift people (http://perso.orange.fr/ballonsolaire/en-index.htm). You need a pretty calm day and bright sun but if you have these conditions it�s a pretty neat trick to get a camera in the air without any additional fuel source. The other option is a fuel powered hot air balloon. A simple lightweight camping stove suspended under a nylon envelope can heat enough air to get a light weight camera off the ground. I don�t go this second option because I don�t really like the idea of having a burning object floating around above me. The important thing to remember about hot air balloons is the lifting capacity depends on the difference in the warmth of the air inside the balloon compared to the outside air. The larger the difference in relative temperatures the better the lifting capacity of a given volume. So, hot air balloons have more lifting potential in cooler days than they do on hot days.
Hydrogen balloons: (don�t even go down this road). Although hydrogen is a safe fuel when handled properly and has great lifting potential, the safety concerns far outweigh the slight increase in lift compared with helium. I choose not to go the hydrogen route and I don�t endorse it.
Helium Balloons: Now this is the way to go. Helium has nearly the same lifting potential as hydrogen but is much safer to handle. To calculate the volume (in liters) of helium required to lift a certain weight (in grams) simply multiply the weight by 0.9743640 . It�s always good to double, triple or even quadruple the amount of helium required to lift the entire camera assembly and balloon in order to make sure the balloon can fight against slight breezes. Helium can be purchased wherever compressed gas cylinders are sold, contact your local automotive parts dealer for the nearest compressed gas distributor. Be wary of the helium that�s designed for filling party balloons, these tanks may include other gasses in addition to the helium which will decrease the lifting potential. Check out: http://www.balloondealer.com/skybuster.asp or http://www.kaymont.com for large balloons.
Kites: These work great when you have steady wind. This statement might sound obvious but you�d be surprised how much wind it takes to get a camera up in the air. Gusting wind isn�t what you�re looking for; it�s the continuous sustained winds that work best. There�s nothing worse than having your kite and expensive camera lost in the forest or even worse having string draped from rooftop to rooftop or disappearing over the edge of a cliff with no camera and kite in sight due to the wind quitting mid flight (I speak from experience). Not only is this a huge headache, it�s a definite safety issue for all concerned. There are special kites like the Sutton Flowform (to name only one) which are used for lifting cameras and instruments. Here is a site that is probably the best resource on the web for aerial photography from kites: http://arch.ced.berkeley.edu/kap/ . Remember that the weight of the camera will effect the amount of wind it takes to lift the rig, if the specifications say it takes a certain amount of wind to fly the kite, be assured that it will take a lot more wind to get it in the air with the camera attached.