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Kite
Camera on the kite
A poor quality still
from a shaky video taken in a gusting wind (see the twisting, looped
tail) but reasonable as the
808#16D
camera was pointing into the sun and
velcroed to the unstable top lower edge of a
HQ Power Sled 1.7 kite! 19
Jan 2013 See also
here
Camera on the kite line
Two tent pegs taped
together with the HD808#16D camera on the left.
Shown without the
safety line. Camera 18g Rig 56g
Total:74g
Safety Line
The two images below are stills
from a video taken with the 808#16D camera -
video
clip. Select
HD using
the cogwheel icon.
Attachment point
formed by two 'large' velcro pads either side of the peg loop with
two small ones in between.
808#16D
camera flown on the above tent peg,
transverse pendulum. Video stills
extracted with the free
VideoLan.
26 Jan 2013
The vertical arm needs to be longer
A coat hanger wire was tried next. A soft
weight, Blu-tack, was added to the end of the long vertical arm. The
assembly should, as a rule of thumb, balance on the finger, just
above the weight. The plastic covered coat hanger below weighs 28g,
the camera 18g and the corresponding added weight is ~140g (later
reduced to 100g).
Increasing the weight beyond this will not significantly increase
the effective length of the pendulum. The effective length of a
pendulum (ie down to its centre of gravity) determines the natural
period of its swing, the shorter the length, the faster it
oscillates.
With this shape, the line tended to slip
down the pendulum and straighten the wire.
A still from
an
808#16D
video (Select
HD using the cogwheel icon in YouTube) using the above coat
hanger wire, transverse pendulum.
2 Feb 2013
The video has not been stabilised and
the above image is not corrected for distortion (wysiwyg).
Some wobble in the long arm is visible in the
video. Increasing the gauge of the wire would improve this or
replacing it with something rigid. This is a relatively light coat
hanger wire, so shortening the long arm can improve the wobble too.
Stability can also be improved by reducing the tension in the line
by walking slowly forward. Later, it was found that reducing the Blu-tack
to ~100g improved stability.
A smaller version
An improved form with kinks to prevent the line slipping.
A smaller version with the same gauge
coat hanger wire and less wobble. The weight with the camera is 91g,
of which 46g is Blu-tack and 18g the camera. This is the most stable
arrangement to date but the pendulum can be longer. Here is
a video clip with the line under tension (ie not slackened to
improve stability) using a HQ Delta Graphic 2m kite. The pendulum
has a transverse swing but the longitudinal component of the swing
is dampened by the tension in the line. Height variation has
negligible impact.
A grey scale,
near infra-red image of the
field to the west of Blackness Castle
using the above modified pendulum. Unfortunately, the camera
detached and was swinging and bouncing on its safety line...but
images, like the one above, were still extractable from the video!
30 March 2013
Kite aerial photography with a slightly longer
version of the above system at the
Hidden Heritage Project excavations in Tarbet, along with
Northlight
Heritage and school groups.
Near
infra-red video clip
17 May 2013
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