Camera Platforms
and Mounts

ES 555 Small Format
Aerial Photography

James S. Aber

Table of Contents
SFAP platforms SFAP camera mounts
Hot-air blimp Helium blimp
Related sites References

SFAP Camera Platforms

The camera platform is the device that lifts or suspends the camera in the air above the ground. Such devices range in sophistication from a step-ladder to high-altitude rockets. The platform may be manned or unmanned. The former are necessarily large enough to lift a person safely along with photographic equipment. The latter may be relatively small. Manned lifting platforms, such as airplanes, helicopters, hot-air balloons and ultra-lights, are fairly expensive to operate and normally require a trained pilot and ground-support crew. Unmanned platforms are much more variable in their technical specifications. The requirements for lifting capability and platform safety are much less stringent with unmanned platforms; the cost and technical expertise needed to operate such systems also vary greatly.

A further distinction can be made between powered and unpowered platforms. The former become airborne through some kind of artifical thrust provided by a motor or engine. Airplanes, autogyros, helicopters, and rockets utilize a variety of wings, blades, rotors and fins to create lift and/or stablize the vehicle in flight. These aircraft move with moderate to high velocity; even the helicopter that appears to hover is in fact rotating its blades rapidly against the air. All powered platforms vibrate and move relative to the ground. Unpowered platforms achieve their lift either through neutral buoyancy (balloons and blimps) or via resistance to the wind—kites and gliders. Balloons, blimps and gliders that drift with the wind move slowly relative to the ground and have minimal mechanical vibration. Tethered platforms—balloons, blimps and kites—tend to vibrate and swing with the wind. Regardless of the kind of powered or unpowered platform, any vibration or movement of the camera relative to the ground creates the potential for blurred imagery.

Unmanned platforms

Quilter and Anderson (2000) described a drone used to acquire low altitude/large scale (LA/LS) imagery for resource management. The drone is a model airplane with approximate 8-foot (2½ m) wingspan. It flies up to 1000 feet (300 m) above the surface and is controlled by a pilot on the ground. Film, digital, and video cameras may be utilized. A single vertical image covers a ground area ranging from 75 m² up to 6½ hectares, depending on camera lens and flying height. The drone-camera system has been utilized to document effectiveness of riparian restoration, to monitor impact of all-terrain vehicles on vegetation, and to evaluate range management techniques. Total cost of the system—drone, engine, radio controls, and camera—was about $1000 as well as 100+ hours labor to build the drone.

Lately small, unmanned drones have become quite popular. In spite of the hype for a new industry, actually flying such drones routinely and effectively for SFAP remains a difficult proposition that requires a skilled pilot. Learning to fly a remotely controlled helicopter takes years of practice—see Binghamton. Such drones are legal for hobby and personal, non-profit use. However, flying for commercial applications requires a remote pilot airman certificate with a small UAS rating—see legal aspects.

Manned platforms

The USDA Rangeland Resources Research Unit, in Cheyenne, Wyoming, has developed an ultralight airplane to acquire very-large-scale aerial imagery (Hunt et al. 2003). The aircraft is a Quicksilver GT 500 single-engine, single-pilot plane that flies a mere 20 feet (6 m) above the ground. The ultralight is equiped with a laser altimeter for precision height measurement. Various high-speed film and digital cameras are utilized to acquire images in the scale range 1:50 to 1:200. Film is 70-mm format ISO 400 for superb resolution and high-speed exposure. The cameras are triggered by a computer interfaced with a GPS unit according to a pre-programmed flight plan and photo coordinates. Preliminary equipment development and field testing have been conducted for monitoring of bare ground cover in the Muddy Creek watershed, Carbon County, WY.

Ultralight aircraft can fly low and slow, which makes them potentially quite useful for SFAP. Nonetheless, they have some limitations both in terms of safety and legal aspects. Three cases from Kansas in 2013 illustrate these issues.

Given this brief review of various platform capabilities, it should be clear that no single kind of platform would be ideal for all types of small-format aerial photography. Key issues are cost, safety, operator expertise, and quality of imagery for a particular project or application. These factors must be weighed on a case-by-case basis in order to select the optimum kind of platform for a given SFAP mission.

Review SFAP platforms.

SFAP Camera Mounts

The mount is the physical framework that holds the camera in a specified position. Mounts can be as simple as a tripod screw that holds the camera to a fixed bracket or as complex as a remotely controlled device for precisely aiming the camera and triggering the shutter. For vertical photography, the mount should be self levelling, so the camera lens is always pointing straight down, regardless of platform motion or position. For oblique views, camera position may be adjusted in two ways.

  1. Pan — Moving the camera's horizontal position through 360°, as indicated by compass direction.

  2. Tilt — Moving the camera's vertical position through 90°. This is indicated by the so-called depression angle, which varies from zero for horizontal to 90° for straight down.

A further aspect of camera mounting is related to film format. Images on 35-mm film may be taken in landscape or portrait format. The former has the long dimension of the picture in horizontal position; for the latter, long dimension is turned vertically. The same is true for most compact digital cameras. For 70-mm film, however, the image is square, so format orientation is not an issue.

Landscape format (left) and portrait format (right) showing downtown
Kansas City, Missouri. Kite aerial photographs © J.S. Aber.

An unusual mount for SFAP was described by Chong and Schneider (2001), who employed a stereo-camera system for photographing dolphins in shallow coastal waters of New Zealand. Two standard Pentax Espio film cameras are mounted on a bar that is suspended from a boom attached to the mast of a sailboat. The cameras are positioned forward of the sailboat bow about 7-8 m above the water surface. Cables attached to the mount allow for adjusting position, tilt and orientation; the cameras are triggered electronically from the boat deck. A video camera is included also at the bar center, between the two film cameras. This setup was used to acquire stereo imagery for measurements of dolphin body sizes.

Camera mounts for small format aerial photography vary greatly in their sizes, complexity, cost, and capabilities. For a manned platform, of course, the camera could be hand-held. As with camera platforms, these factors must be considered on a case-by-case basis in order to select the optimum kind of mount for a given SFAP application.

Hot-Air Blimp SFAP

An innovative system will be described as a case study for small format aerial photography. Marzolff and Ries (1997) and Marzolff (1999) utilized a specially designed hot-air blimp for SFAP geomorphic and vegetation investigations in Spain. Their blimp (zeppelin) is approximately 10 m long and has ~100 m³ volume. The blimp is manuevered via a ground tether. The propane burner and camera system are operated by radio control from the ground. The blimp flies up to 400 m high and can lift a payload of 6 kg.

Hot-air blimp in the field near Jaca in the Pyrenees Mountains, Spain. Original 100 m³ blimp system with small payload setup. Image courtesy of I. Marzolff.
View from the blimp down to the launching site, province of Zaragosa, Spain. Image courtesy of I. Marzolff.

The cost of the fully equiped, custom-built hot-air blimp system was approximately $12,000; the dual-camera system and radio control apparatus cost $1500 and $600 respectively. A minimum of four people are necessary for ground operation of the system. The whole system can be packed into bags and aluminum cases for easy transportation via automobile or backpacking. Dual Pentax cameras are utilized for simultaneous photographs of the same ground area. In the original configuration for the smaller blimp, one camera was loaded with normal color film, and the other carried color-infrared film and an orange filter (to remove blue and green light). Storage batteries power the radio receiver and control devices. The propane burner and cameras are operated by remote control from the ground.

Dual film-camera mount in the basket underneath the blimp. The camera with orange filter takes color-infrared photographs; the other camera takes normal color pictures. This is an older configuration that is no longer utilized. Image courtesy of I. Marzolff.
Normal color image of abandoned farm near Jaca in northern Spain. Image courtesy of I. Marzolff.
Color-infrared image of abandoned farm near Jaca in northern Spain. Image courtesy of I. Marzolff.

Ries and Marzolff (2003) subsequently obtained a larger and more capable blimp (11 m long, 220 m³), and a new camera system was designed. One camera carries film and the other is high-resolution digital; each may be equiped with a different lens to obtain various viewing angles for simultaneous pictures. In addition, a small video camera is mounted to aid in positioning each scene. The cameras are mounted on a turn-table that can be rotated for framing pictures. At present all pictures are acquired in vertical mode, as the camera system cannot be tilted to the side for oblique views. Image processing is carried out with Idrisi software, which allows for photogrammetric and multispectral analysis.

Ground testing propane burners for hot-air blimp system. This is the larger framework for the 220 m³ blimp. Burners are activated by radio control. Photos © J.S. Aber.
Hot-air blimp payload with camera basket held aloff by students at Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany. Project directors, Johannes Ries and Irene Marzolff appear on right side of view.
View of camera basket (upside down). A - high-resolution Canon digital camera with zoom lens, B - 35-mm Pentax film camera, C - video spotting camera. The cameras are triggered simultaneously by radio control.

The hot-air blimp SFAP system has been developed experimentally for the EPRODESERT project. The project was undertaken to study the reasons and consequences of soil erosion and land degradation in northeastern Spain. The ultimate products of SFAP from the blimp are large-scale, high-resolution images that can be mosaicked and georectified into maps. Such maps serve as the basis for further scientific investigations and interpretation of site conditions.

Image map mosaicked from five photographs. The map depicts a large erosional scar in a mountain pasture near Jaca, northeastern Spain. Image courtesy of I. Marzolff.

MoGul aerial photographic monitoring.

Advantages and disadvantages of hot-air blimp for SFAP.
Adapted from Marzolff and Ries (1997).
Advantages Disadvantages
  • Flexibility for SFAP
  • Ease of transportation
  • Quick setup in the field
  • Stability and lack of vibration
  • Low-tech components
  • Availability of propane worldwide
  • Danger of power lines, trees, towers, etc.
  • High cost of equipment and operation
  • Large field crew necessary
  • Wind — More than slight breeze unsuitable
  • Related sites


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    ES 555 © J.S. Aber (2016).