The Balloon as a Vehicle for Aerial Photography

August 2001

At first glance the use of balloons in aerial photography would appear to be a fine idea. You don't need to wait for a breeze, helium's not that expensive and balloons of various sizes are available almost anywhere. Well, as they say, "the devil is in the details". When you actually go ballooning problems begin to emerge.

It turns out that a 36" diameter balloon (the largest readily available in my town) will just barely lift the lightest camera rig. In fact, given the variations in inflation pressure at my local balloon store, this is by no means a given!

36" Helium-filled Latex Balloon	Lift (oz.)
1st balloon	6.5
2nd balloon	4.8
	Average 5.65
Film Camera Rig	Weight (oz.)
Smithsonian Aerial Camera kit	1.0
Fujifilm Quicksnap Outdoor camera	2.3
	Total 3.3

If my high school physics holds up, then the next smallest balloon I saw, 12", would have to be used in groups of 27 to achieve the same lifting capacity! So, while the initial cost of an inflated 36" balloon is a bargain at about $5, achieving the same lift with smaller balloons at about $1 apiece becomes quite pricey.

Digital Camera Rig Weight (oz.)

Agfa CL-20 digital camera 5

2 x AA batteries 1.75

timer electronics 1

wire frame to hold it 3

Total 10.75

Then there's the issue of timing. My 36" balloon lost about 1/2 an ounce lifting capacity in a day. In a week it went from 6.5 ounces of lift to 2.2 ounces. For a device with such marginal lift capacity this means you have only a few days to use the balloon. That is, unless you get a helium tank and re-fill it yourself.

Digital Camera Rig	Weight (oz.)
Agfa CL-20 digital camera	5
2 x AA batteries	1.75
timer electronics	1
wire frame to hold it	3
Total	10.75

Even with both balloons filled up you'll just barely have enough lift for a small digital camera.

You can't buy helium tanks easily, but you can rent a "4 foot" tank for a year at $60, plus $55 for the regulator/gauge assembly. Each helium refill costs $55. This contains 244 cubic feet of helium, or about 20 refills of a 36" balloon. I think all this must be making some assumptions about temperature and pressure, but these are the terms in which the local helium dealer expressed it. You can rent a "2 foot" tank as a 3-day rental for $28.

One last practical issue is how you transport the balloon. 36" is a BIG balloon. I can just fit it into the rear hatch of my compact wagon.

Experimental Results

The results of my experiments with the Smithsonian Aerial Camera and balloons were very disappointing. It appears that the pull of the shutter release string caused the camera to move enough to blur the image. This happened in most of my kite-suspended tests with this rig too.

A more fundamental problem is that balloons are not very stable in the wind. I guess the round shape just gets pushed every which way. Basically, balloons are a tool for zero wind days. Alternatives would be to make the balloon a different shape like a blimp, insert it in an envelope and frame like a rigid airship, or attach it to a kite (see Nature, Vol. 36, the "Kite balloon").