Aerial Photography

This photo of the most eastern part of the San Diego Country Estates shows the James Dukes Elementary School on the lower right and the Ramona Oaks Road heading straight East, on the upper left side.

Eagle Peak  (Elevation: 3,226 ft / 983 m) and Cuyamaca Peak (Elevation 6,512 ft / 1,985 m) are clearly visible in the  East (upper left).

This shot was taken from a so-called multirotor unmanned aerial vehicle (UAV). More precisely, I used a quadcopter (a multirotor helicopter that is lifted and propelled by four rotors) equipped with a small very light-weight camera.

Aerial Photography is the taking of photographs of the ground from an elevated position. The term usually refers to images in which the camera is not supported by a ground-based structure. Platforms for aerial photography include fixed-wing aircraft, helicopters, and multirotors.

Usually, for a shot like that, I’d rather use my trusted Canon DSLR camera, with a good lens, weighing a few pounds. However, with a quadcopter (sometimes simply called a quad) that’s not not an option. Every ounce you add to the vehicle reduces stability and flight time, if it takes off at all.

Quadcopter w/ Camera

This is the quadcopter, equipped with an extremely light-weight camera, that took the photo. The shot was not triggered remotely, I simply set the camera to take a photo every three seconds (a.k.a. Time-lapse Photography) and was hoping to get some useable photos, while maneuvering the Quadcopter in the sky.

The camera didn’t let me down and I got some decent shots. It’s obviously not DSLR quality, but not bad either, considering that a my Canon 7D, even without lens and battery, comes in at 820 grams and this little camera (also capable of shooting 1080p video at 30 fps) weighs only 39 grams and that already includes the battery.

Shooting video in either 1080p/30fps or 720p/60fps originally showed some serious jello effects (the rolling shutter causes the image to wobble unnaturally and bizarrely, due to the camera being mounted on an intensely vibrating vehicle). However, installing a simple and cheap vibration isolator, reduces the issue significantly.

Quadcopter Camera still without the vibration isolator
Quadcopter Camera still without vibration isolator

The weight, supported by those vibration isolators, like shown in the photo below, depends on the hardness of the four Anti-Vibration Absorber Rubber Balls.

Quadcopter with anti-vibration camera mount.
Quadcopter with anti-vibration camera mount.

Crisscrossing over the Tech Casita


Neutral Density Filter

The Mobius Actioncam uses a rolling shutter (the camera does not record a complete snapshot of each frame, but scans vertically across the frame). This means that not all pixels of a frame were recorded at the exact same time, leading to the jello effect or wobble.
While the vibration isolator gets rid of most of the jello effect, we can do even better. Reducing the amount of light that gets into the lens, will slow down the Actioncam’s high shutter speed, and thereby increase the number of pixels per frame, which were shot the same time.

Mobuis Actioncam w/ ND2 Filter
Mobuis Actioncam w/ ND2 Filter

An ND filter is a piece of translucent acrylic or glass, sitting in front of the lens and reduces the amount of light reaching the sensor by a set amount. The amount of light reduction achieved by an ND filter is defined in stops (one stop being a 50% reduction in the amount of light). An ND2 filter reduce one gear of the aperture, average transmittance of 50%.

Unedited 1080p/30fps DJI / Mobius footage

1080p/30fps with Vibration Mount and ND2 Filter applied