Sunday, July 5, 2009

My Next Generation KAP Is Here

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Here is the first look at my new camera rig built from Brooks Leffler KAP parts and James Gentles’ gent360-LED.

The LED trigger and servo runs off 4 NiMH rechargeable cells

The IR Led had a PIC built in so that every 10 seconds it triggers the camera and rotates the modified servo 60 deg. This is an older 3.2 Meg pixel camera I am using because of it's remote control capabilities.

I also bought a 12' wing span Delta which I lightened by replacing the semi-solid fiberglass spars with hollow fiberglass spars.

Friday, August 29, 2008

August 10, 2001 Ocean City, MD

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You can tell I am using my upside down mount here. Note the text in the image.

March 12, 2001 Pratt Park

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Butler Road WMCA
Softball fields behind the WMCA
Looking East toward Chatham Manor

Picavet In Flight

March 2001. First flight and test from Pratt Park south Stafford.

Picavet Suspension

Over a century ago M. A. Batut's kite aerial photography apparatus involved a camera attached directly to the kite. By 1906 George Lawrence was suspending the camera from his kite line (cable) well below his train of kites. Separating the camera from the kite reduces camera motion and thus lessens blur in the image. By 1912 Pierre L. Picavet was describing a cross-shaped suspension we now call the Picavet. It involved a rigid cross suspended below the kite line with each of the cross' four ends connected to two attachments on the kite line. The line providing these connections is a continuous loop. Its attachment to the kiteline and Picavet cross sometimes involves pulleys. The result is a nominally self-leveling platform that resists a turning moment (as in the camera cradle rotating below it.)

This diagram of the Picavet shows the systems major landmarks. The cross dimensions seem to vary from 20 inches across to as little as 3 inches. The loop of line that threads between the cross and the kite line attachment points is often 50 feet in length. A small split ring (R) is used to constrain the two innermost lines as they cross. Using the labels on the diagram as a key, a suggested threading sequence is
A1 - 1 - B1 - R - 4 - A2 - R - 2 - B2 - 3 - A1.

Through much of this century the Picavet suspension was a lost idea and most KAPers used a pendulum-based suspension (see Kite Aerial Photography by Mark Cottrell, 1987). In 1988 the Picavet method was rescued from obscurity by Michel Dusariez in an article published by the Kite Aerial Photographers Worldwide Association (KAPWA). More recently the Picavet was described in an Aerial Eye article by Ralf Beutnagel, Wolfgang Bieck, and Otto Bohnke (Picavet - Past and Present, Aerial Eye, Vol. 1, No. 4, Fall 1995). The Picavet is now a popular means for suspending camera cradles from the kite line.

I was very fortunate to have a very talented Machinist working for me at the time that spend some off hours building my first and only KAP cross. I used small, inexpensive hardware pulleys and as a first attempt and just hung the camera upside down off of a ball socket.

The attachment point (below) allowed a loop of line to pass where the nail is now and looped back onto the "T" notch.

Kodak DC260 circa. 2001

Technical Details
1.6 million (1536 x 1024) pixels per image
3X optical plus 2X digital zoom
Audio-record and playback
Store up to 95 pictures on each 8-MB card
One of the options was the ability to take X number of images in X number of minutes. This is how I managed to get KAP images without a remote control.

Batman Rules All Others Drool

My 8 foot wing span Delta-Conyne (DC) cir. 1998. It was my first attempt at sewing a kite. I used wooden dowels and soft rip-stop nylon from a fabric store, not the coated spinnaker cloth that is used in so many kites today. It is still my favorite kite but has been flown so much at the beach it is severally sun damaged and is now retired. The Batman symbols were appliqued on the wings to cover burn holes from the hot knife I used to cut out the material. It was a high flyer and with a steady beach wind had no trouble lifting my first generation pivacat suspension and the Kodak DC 260.