0

How do I place a light-weight point and shoot camera on a balloon filled with helium gas?

mattdm
  • 143,140
  • 52
  • 417
  • 741
user275517
  • 311
  • 1
  • 3
  • 8

1 Answers1

6

I hope it is obvious that the heavier side of the balloon will swivel to the bottom. Even if your camera is amazingly light, you will need a counterweight to balance that — something slightly heavier than the camera is the easiest. (You could also do several weights distributed in a balanced pattern. But either way: more weight!)

Once you have the counterweight, and the camera, the rest is reasonably obvious. This is going to be a fairly large balloon — not something you pick up at the florist. A standard balloon will only lift a few grams. Assuming you have something like a GoPro at around 200 grams, with the counterweight (for a total of 400g) you're going to need something like three-foot diameter balloon. If you have a heavier point and shoot camera, it will need to be even larger.

The ham radio club at the University of Hawaii has a nice page on balloon lift, which covers not just the amount of helium needed but different balloon types as well. (It doesn't cover mylar balloons, though, and I don't think you have many commercial options there, because even the so-called "jumbo" balloons are less than 30" in diameter inflated, and not actually spherical, so much, much too small.)

Once you've got that, though... use tape or whatever else to attach your camera and the counterweight, and there you go.

mattdm
  • 143,140
  • 52
  • 417
  • 741
  • 1
    Non-relevant for photography addendum: 1 liter of helium lifts 1 gram, so to lift 200 grams you need 200 liter of helium. Using this Google tool you can find that a sphere of 200 liter has a radius of 0.36 meter. – Saaru Lindestøkke Jul 21 '14 at 02:42
  • 2
    @BartArondson And here, with the counterweight, we need more than twice that, so, almost exactly a minimum radius of 18" — a diameter of 3'. – mattdm Jul 21 '14 at 03:03
  • 2
    Hey, make the counterweight another GoPro! – Paul Cezanne Jul 21 '14 at 12:18
  • @mattdm Ah I mixed some stuff up. I found compact cameras that weighed 100g (including batteries) so I assumed 200g as the total weight. But indeed, if you have a GoPro and a counterweight (or two GoPro's) you are right. – Saaru Lindestøkke Jul 21 '14 at 13:13
  • Don't confuse radius and diameter. 200 litres is a balloon that is 0.72metres from side to side. That's if I'm even using the calculator correctly. If you put in 200 as V you get an 'r' output of 3.63?, which as i understand is a balloon 7.26m wide. If I go here: http://www.handymath.com/cgi-bin/solidsphere.cgi i can specify the input and output units which should make it easy to calculate, and it returns the diameter so you don't have to do an additional calculation on the radius – laurencemadill Jul 21 '14 at 13:29
  • 1
    @laurencemadill The Google tool wants input in m³ (and one cubic meter is a thousand liters.) – mattdm Jul 21 '14 at 13:32
  • @mattdm ah now that makes sense, so when I input 0.2 I got the right result, 0.2 of one m³ – laurencemadill Jul 21 '14 at 14:33
  • A GoPro Hero3 (without any housing) only weighs 75g. Though the waterproof housing could add another 100g, plus the weight of any mounts etc. You can use it without a housing, maybe attach it to the balloon with elastic bands etc, could be pretty lightweight. – vclaw Jul 21 '14 at 22:54