Category: Photography

Photosynth Thesis

A couple of weeks ago I took some photos and video from the KAP rig lofted on the Flow Form 16 kite above a clearing behind the house. I did not get far stitching the images into a panorama, and had to move on to other business. Since then I have used Photosynth, which will not only display stitched panoramas, but the multiple unstitched overlapping images. The photos do not need to be taken from the same place, so KAP images should be well suited. Photosynth will create and display a 3D model of the surfaces in the photographs. The model consists of the points that Photosynth has determined are shared in two or more photos, and the 3D plot of those points based on photogrammetric analysis of the images. You can toggle a display of the point cloud in the Photosynth viewer below.

The final flight of the Fled

Bird's eye view, Salisbury, VT

A postcard from ca. 1900 with a view of the village of Salisbury

Around the turn of the 20th century, a postcard was made with a view of the village of Salisbury, Vermont from a field on the side of a hill. Repeating this photo would highlight the dramatic changes since then, such as the draining of “Mirror Lake,” and the rampant increase in shade trees in the village. But trees also cover the hillside now, so it is not possible to reoccupy the original camera location. I have had this project in mind as I practiced kite photography, wondering how I could fly a camera over the trees close to the proper place. When Friday afternoon arrived sunny and breezy, I hopped in the truck and headed to Farwell Lookoff, the site of an old cabin at the top of that same (now forested) hill. I had been there only once before, and did not remember whether the cabin occupied a large enough clearing from which to launch a kite. The jury is still out on whether it does.

Built to fly

I awoke this morning to see that not a leaf on the hornbeam was fluttering, and my head fell back to the pillow in dismay.  This was a sure sign that I had a new hobby.  It was the KAPer’s lament: no wind. I had flown a camera on a kite for two days in a row, and the thought of a calm day was discouraging.  But I had started a stitch of yesterday’s aerial panorama before I went to bed, so I got up two hours before Galen had to be at school to check on it.

All the parts before assembly

All the parts before assembly

I built my first KAP rig last week from one of Brooks Leffler’s kits. I have never built anything with servos and dip switches and carbon fiber legs, but I got to use my Dremel tool, so it felt safe.  Brooks has designed an elegant system for suspending a camera so that it can point in any direction.  The pointing and shutter release are done either at predetermined intervals (autoKAP), or by radio control from the ground.  The kit I built had servo motors for both panning and tilting and electronics to automatically point in as many as 76 directions and take photos potentially covering a downward-looking half-spherical view. By replacing the tiny circuit board with a radio receiver, the motors and shutter could be controlled via a transmitter on the ground.  It is based on the RC airplane/car/boat/helo standards, so compatible equipment is readily available.

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