Get Above It All

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The camera sweeps low and steady across a field of large boulders, trees and a wide river whose water churns inexorably toward an unknown destination. Suddenly, the ground drops away revealing a thunderous waterfall. Millions of gallons of liquid are in free fall and a colorful rainbow arcs across the billowing mist.

The Phantom quadcopter with GoPro HERO3 camera attached.

During the entire history of photography, perspectives from above have been difficult, if not impossible, to capture without budgets large enough for the chartering of full-sized aircraft (helicopters and airplanes). Aerial imagery provides an unparalleled sense of scale and context to a story, but the challenges involved in achieving such shots have prevented most photographers from even attempting to get them. In the past few years, developments in a new form of remote-controlled unmanned aircraft systems (UAS) called "multi-rotors" have opened up easy-to-accomplish, aerial imagery to photography on a budget.

The Quadcopter That Changed Everything
In December 2012, a Hong Kong-based company called DJI Innovations released a ready-to-fly (RTF) quadcopter called the Phantom. Inexpensive, toy quadcopters had begun to be available on the market, but the DJI Phantom differed in that it targeted mainstream pilots rather than hobbyists wielding soldering irons. It was truly ready to fly out of the box, featuring a GoPro camera mount and a GPS flight mode that would hover the quadcopter in place, by default. Overnight, it made aerial imaging accessible to just about everyone.

DJI has since announced the Phantom II and Phantom Vision, which likely will be shipping by the time this issue hits newsstands. The new quadcopters feature more power and extended flight times, and the Phantom Vision includes a built-in camera and a mobile iOS app that supports real-time video previews, camera control and telemetry via a repeater that clips onto the transmitter (allowing for app-to-aircraft communication far beyond typical Wi-Fi range). Competitors have also emerged on both sides of the Phantom, including the Blade 350 QX ($469.99) on the toy/hobby side and the 3D Robotics Iris ($729.99), a proper "drone" with autonomy and open-source community support as emphases.

Cheng launching the Phantom from a Tongan beach.

The Phantom and its recent competitors are fantastic, entry-level UAS for aerial imaging because they hide a lot of complexity from the pilot. The Phantom, in particular, is to be commended; no other quadcopter has been around for a year of proven, reliable flight for so many beginner pilots.

It only takes a few minutes to set up the Phantom for flight, and its GPS flight mode allows a prospective aerial photographer to launch the quadcopter into a stable hover at any altitude without requiring advanced piloting skills. The Phantom comes with a GoPro camera mount and the mount supports both housed and unhoused GoPro cameras. Although an unhoused GoPro reduces payload weight, new pilots might want to fly with their GoPros housed to protect the camera during crashes. Lighter cameras are certainly available, but GoPros take both high-quality stills and video, and are a good value for their size and cost.

Setting Up For Flight
The Phantom comes packaged in a box that takes cues from Apple product packaging, and all one needs to do to get in the air is to screw on the landing struts, attach the propellers, put 4 AA batteries in the radio, and charge/attach the battery. The Phantom uses DJI's Naza-M flight controller, which DJI also sells as a standalone flight controller targeted at multi-rotor hobbyists. A Naza-M flight controller with GPS costs $399 by itself, which suddenly makes the Phantom especially attractive.

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Shooting from the air allows you to get some special perspectives. Here, snorkelers mingle with whale sharks off Isla Mujeres, Mexico.

The Phantom turns on when its 11.1V, 2200 mAh battery is connected. Left alone on a stable surface, it goes through startup calibration and then begins to lock onto GPS satellites. When the multi-color status LED on the back starts to slowly blink green, the Phantom is ready for flight and has locked onto at least 6 GPS satellites, the minimum number required for reliable GPS flight control. The radio transmitter is a standard, 2-stick radio configured in what hobbyists refer to as "Mode 2." One of the great things DJI has done to push quadcopters toward the mainstream is eliminate all such jargon from the Phantom. Turn the radio on, and it just works. The left stick controls throttle (motor power) and yaw (turning left and right), and the right stick controls pitch (forward and backward) and roll (banking left and right). In GPS mode (selectable by a switch on the radio), the Phantom will hold GPS position at the current altitude, so steady hovers are easily achieved, even in wind. I've flown the Phantom in winds as high as 15 knots with 25-knot gusts, and it was rock-solid.

In practice, the Phantom can be flown even by new pilots, but I highly recommend conducting your first few flights in a large field with no trees or power lines around. If you have spectators with you, keep them away from the quadcopter and let them know when you put it up in the air. The one ground truth about these quadcopters is that if you lose control, they likely will crash into things before you even know what happened. Once you can fly figure eights without thinking, you've achieved the first level of multi-rotor pilot mastery.

The ultrawide lens on the GoPro does introduce some distortion, but it can be somewhat corrected in the computer or you can just go with it.

The Phantom has a couple of other flight modes (as do its competitors). Course Lock is a mode where the starting orientation of the Phantom is recorded as "forward." Regardless of how much you yaw the aircraft in Course Lock mode, pushing the right stick forward will make it go in the recorded direction. Home Lock is a mode where "forward" is always a vector between you and the aircraft. At any point, you can pull straight back on the right stick to bring the Phantom home. Speaking of home, one of the greatest features of the Phantom is that it has a powerful failsafe mode. If the Phantom runs low on battery or loses contact with the radio, it simply will fly home and hover at 20 meters in altitude. When the battery becomes completely drained, it will land automatically. Fail-safe is a good last resort, but is something that shouldn't be relied upon during normal flight.

Shooting Stills And Video With The Phantom-GoPro Combination
The Phantom is so easy to fly that most people attach GoPro cameras to them long before they're competent pilots. The two most common recording modes used during aerial imaging are Video mode and Time-Lapse mode. Wide, Medium and Narrow fields of view are all perfectly acceptable, but beginners should probably shoot at 60p (frames per second) for reasons I'll discuss later. In Time-Lapse mode, a 2-second interval is a good compromise between shooting plenty of frames and not coming back with 1,000 pictures to sift through.

After successfully shooting video and stills during a few flights, you may notice some strange artifacts in your results. In video, you may see waves of horizontal artifacts moving through your frame over time, and in stills, you may have strange distortion in horizontal bands of pixels. These artifacts are commonly called "jello," caused by a combination of airframe vibration and the rolling shutter used in almost all CMOS-based cameras like GoPros. Jello comes from high-frequency vibration originating in the motors and propellers, and not from airframe movement that comes from wind or the automatic stabilization movements during flight. Jello can be prevented by a few tweaks to your Phantom:

1 Shooting at 60p reduces the amount of rolling-shutter artifacts in video.

2 Balance the propellers. Hobby stores sell "prop balancers," which can be used to make sure your propellers are in balance so they don't vibrate back and forth when they're spinning. The best way to learn how to balance propellers is to do a search on YouTube for "prop balance." Note that the Phantom II and Phantom Vision's propeller design has been changed to remove the need for a tightening nut, which may complicate prop-balancing.

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Using a monitor, you can see what the camera sees as you're flying the Phantom.

3 Insert vibration isolation between the GoPro mount and the airframe. Many third-party manufacturers, mostly small, mom-and-pop shops on the Internet, sell vibration-isolation mounts specifically designed for the Phantom. These isolators use silicone dampener balls or wire isolation and are easily installed between the GoPro mount and Phantom. Be sure to look for one that isn't too thick, or you may have to order third-party landing struts to increase the usable height between the Phantom and the ground.

4 Buy a gimbal. Brushless gimbals stabilize the camera in roll and pitch directions and keep the camera absolutely level during flight, even when the aircraft is rolling and pitching aggressively. Brushless gimbals require vibration isolation to work properly, so they typically come bundled together. Using a brushless gimbal is absolutely the best way to get stable video; we'll discuss gimbals in detail in the next installment of this series in Outdoor Photographer.

Any GoPro HERO camera will work well to capture aerial video and still pictures from a quadcopter like a Phantom, but using a HERO3 will give you the best-possible image quality from a lightweight camera. The HERO3 shoots fisheye stills at 12 megapixels, allows you to select between Wide, Medium and Narrow fields of view, and includes the highest-bit-rate Protune support, allowing video recording at around 45 megabits per second (Mbps) without contrast or saturation applied for the best possible raw video source from a GoPro. Even without a gimbal, you'll be able to get fantastic still images and decent video from a new perspective. You'll be able to differentiate yourself as a photographer and give totally new context to your next photo essay.

Eric Cheng is an award-winning underwater photographer, publisher and technologist. Caught between technical and creative worlds, Cheng holds bachelor's and master's degrees in computer science from Stanford University, where he also studied classical cello performance. He's the founder of Wetpixel.com, the premiere community website for underwater image makers. See more of his work at echeng.com and skypixel.org.