KAP - Taking photographs from a camera pulled into the air by a kite.
I am very interested in the subject of kite aerial photography (KAP). The first rig I made crashed after I had taken only two pictures and the camera was broken. The second rig worked better but it was soon involved in an accident (described in the second rig section below). My present rig is more advanced but still has some problems.
| First camera rig | Second camera rig | Improvements | Completely new rig with Picavet style suspension |
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This page last updated: 6 Jan 2000 |
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Have a look at some of my
kite camera photographs .
Several other web sites have galleries of their photos. Click here for links. |
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First KAP rig
To prepare the
camera to take a picture, I place a loop of thread between the two hooks (A and B), so
that the clothes peg is held open. I then put a Storm match (a bit like a fuse on a
matchstick) through the two lengths of thread, open the lens cover, light the match, and
let the kite pull the camera as high as possible.
The Storm Match usually takes 4 or 5 seconds to burn down. It burns through the thread, releasing the clothes peg, which presses the shutter release button and takes the picture. I might use a sparkler instead of the match because the camera could be pulled higher into the air before the picture is taken. From the pictures that I have now got developed, I can see that the camera was still shaking about after being pulled up when the pictures were taken, so the extra time a sparkler allows would let the rig settle down.
Second KAP rig
The second rig was much like the first, but I refined it in a few ways.
Take a
look at the drawing to see the changes. I put the fin over to one side (for no particular
reason) and the camera is now held in the framework by two bolts which pull the top and
bottom plywood pieces together. This holds the camera very firmly in position and it can
be removed quickly by unscrewing the wing nuts from the bolts. The camera can then be
used as normal without getting damaged by the clamp. The first rig was glued onto the
camera with epoxy resin, so it was unusable for normal photography. I couldn't remove the
glue without causing more damage.
The
first rig was very awkward to prepare because the loop of thread was difficult to tie
properly, wasting photography time. The second rig has a crocodile clip to secure a
single thread at one end, after it has been wrapped around the other end. This is a lot
quicker to set up and the thread is more likely to break when required than before. I
glued lots of small pieces of soft plastic foam onto the corners (shown in the
photograph) to protect the rig from damage.
Unluckily, when I was out trying to get it working, the string of the kite broke at the handle and the rig was dragged along the ground over rocks and grass. I had to sprint to catch up with it and then I dived onto it so it couldn't get away. It was mostly smashed up by this stage anyway, so my weight didn't do any more damage. Amazingly, the camera itself survived with only a small scratch on one side.
Although the rig got broken, I was able to glue it together again. Unfortunately, the string on my kite was not very strong at all, so I had to wait until I got some new string before I could test the repaired rig. I tried to fly it again with two strings attached for extra strength. One string broke suddenly, and the other string pulled incredibly strongly. I quickly tried to wind in the remaining string, but about ten seconds later it snapped too. The kite (which was only about 15 metres up) blew for about 150 metres before landing. Admittedly, the wind was quite a bit stronger than usual, but I still needed stronger string if the camera was to be safe.
An addition to the rig to reduce vibration
When I was flying the camera rig, I noticed a lot of vibration of the rig. Vibration is
very unwelcome because it blurs the photographs. A fast shutter speed can remedy this,
but I am using a cheap compact camera with no control over shutter speed, so I have to
tackle the problem at the source. The rig was attached to the kite line with a single
string, so it tended to swing about like a pendulum in the air.
I solved this problem by suspending the rig from two points on the line. This stabilises
it a lot, but sudden movement of the line can still cause shaking. I then put two
flexible kite spars onto the rig, pointing out at the front in a 'V' shape. The ends of
each spar have wire wrapped round, which attaches to the line above them. There is also a
wire going from the back of the camera rig to a higher point on the line.
When this rig flys, it remains especially steady. You can see the spars bending as the kite soars upwards and then straightening again as the kite reaches its maximum height. I have taken two photographs with this new setup which I expect to be sharp, because the rig was very steady when the shutter release device snapped shut.
Completely new rig for the camera
Before I went on holiday for a week, I wanted to get a rig that could be pointed in any
direction and which could take portrait (as opposed to landscape) photographs. I also
wanted to have a Picavet style suspension to keep the rig horizontal whatever angle the
kite line was at.
I built a
new rig by hot-melt glueing pieces of plywood together to the required shape. Aluminium
would have been better, but I can't get it here. I have the usual Picavet cross at the
top of the rig, connected to a right angle bracket which can be rotated in the horizontal
plane. This bracket is in turn connected to the camera holder (a reinforced version of
the clamp action holder from the second rig I made) with a joint that can rotate in the
vertical plane.
To take portrait photos, I have to get the camera held so that it is rotated to the vertical position. All I have to do is remove the right angled bracket, so that the camera is bolted to the Picavet cross. Unfortunately I can only rotate the camera in the horizontal plane because there is no bracket.
The Picavet style suspension is not really a true Picavet design.
It
consists of the bar at right angles to the direction of the kite line being permanently
held horizontal with a string from each end tied to the kite line (see diagram). The bar
parallel with the direction of the kite line is connected at two points by two strings.
One string is tied at one end onto the kite line lower down from the string for the other
bar (mentioned earlier). It then passes through an eye hook at the front end of the
Picavet cross, and up to be tied again at a point higher up the string than the first
bar. Another string follows this pattern but through an eye hook at the back of the
cross.
The rig stays reasonably horizontal (pulleys would be better than eye hooks) and the angle of the camera stays set where it should be. When I was testing this rig the kite wouldn't lift the camera up. The person holding the string ran back to get the rig up, but it just came down again, and the sparkler I was using as the delay started a small fire in the dry grass in the field!
I have used sparklers for most of my latest photographs because they give the rig time to settle down after its shaky ascent into the sky. Storm matches are still useful when I only let the rig up a few metres, as the rig steadies rapidly.
I have taken some photos of my new rig with the Picavet-style suspension (see them on this page)
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