Small format aerial photography (SFAP) is an incredibly flexible and easy way to obtain high resolution images of the ground and its features, both natural and man made. With the use of kites, blimps, and other radio controlled platforms, cameras can be easily and cheaply sent aloft to take pictures, which can then be used for a myriad of purposes. The SFAP class offered at ESU in the spring of 2005 took several field trips, and this report is an explanation and analysis of some of the images taken during one of these trips. This report begins with an explanation of how the images were collected, followed by a description of how they were processed and manipulated, and ends with a discussion of the practical uses and limitations of this approach.
On the 15th of April, the SFAP class took a field trip to the Nelson-Atkins Museum of Art in Kansas City. The wind was blowing less than 3mph, so a blimp was used instead of a kite to get the cameras aloft. This takes a bit more time to prepare for flight than the kites, although once inflated, it is quick to use and easy to handle. The blimp is inflated with helium, and the openings are secured to prevent the loss of the gas. Then the camera rig is attached to grommets on the underside of the blimp. The line is handled with the same wooden reel system that the kites use. Once aloft, the camera rig is controlled by a radio controller; this has the ability to control the pan and tilt of the camera, as well as engage the shutter button.
Click any image to view the full sized version.
Unfolding and inflating the blimp for use.
Inflating the blimp with helium.
The blimp is almost inflated and ready to go.
Tying off the tail of the blimp after inflation.
The blimp in flight in front of the museum. The wooden rig used to control the line is visible in this shot.
Double checking the camera before flight. Patrick Laird (in red on the right) holds the radio controller that moves the camera rig.
After bringing the cameras down to Earth and downloading the images to a computer, some work is required to make them presentable. This is done in Adobe Photoshop. As can be seen from the 'before' and 'after' pictures below, the changes are slight, but the difference is clear. The raw images collected are slightly fuzzy from the camera being subjected to the motions of the wind and technical restrictions of the shutter speed. Also, the camera's auto color balance changes with every shot, depending on what is in the frame. This can be good or bad, but the end result is that most images need some minor tweaking of brightness, contrast, color levels, and the application a sharpness filter.
The original image.
The same image after tweaking the settings. Notice that details are more visible, such as the definition of tree shapes, and that the colors are more natural and less washed out.
© 2005 Jeremy Aber