Story and photography by Ralph Bendjebar
UAVs (Unmanned Aerial Vehicles/drones) capable of recording unique and memorable images and high-quality videos are becoming ever more ubiquitous and affordable. Their capabilities in terms of stability, camera control and image quality have multiplied at a dizzying pace over the last few years. There are a great many choices in terms of equipment, and it is outside the scope of this article to attempt to cover them all. What I will do, however, is provide some helpful tips that will ensure that your photography and videography will produce successful results.
I currently use the DJI Inspire and Phantom 4 UAVs to obtain both video and still images. They are far and away the most widely used UAVs, and while there are many other capable drones on the market, I will limit my discussion to how these two have distinct roles in my UAV toolbag.
The Inspire is a quadcopter with retractable arms that allows 360-degree gimbal/camera rotation without the arms getting in the shot. It has an interchangeable gimbal mount that accepts several gimbal/camera versions, from the original Zenmuse X3 camera that has a Sony Exmor sensor capable of 12 MP RAW and jpeg stills and 4K video, to the X5R which has a Micro 4/3 sensor capable of 4K RAW CinemaDNG recording and interchangeable lenses. It is highly maneuverable, stable and reliable. Dual-operator control—where one operator pilots the craft while the other controls the gimbal/camera—makes it possible to execute more complex maneuvers.
The Phantom 4 is a much smaller, fixed-gear quad that nevertheless carries the same sensor and specs as the Inspire X3. The Phantom 4 also has incorporated a capable forward collision-avoidance system that makes it ideal for shooting situations in tight spaces. It is not as stable as the Inspire in high winds and must be yawed in order to pan a shot. It is, however, easily transported onboard an aircraft, which can be an advantage, as the lithium batteries powering these craft cannot be transported in checked baggage.
Both craft use the DJI GO app, which provides a low-latency 720p video view of what the camera sees on an iOS or android tablet mounted to the radio controller. The app also enables camera control of shooting functions in both photo and video modes. Start/stop functions, file size and type selections are available and Intelligent Orientation Control is selectable in the app for craft maneuvers such as Point of Interest, in which the craft circles a point while the camera remains focused on the subject. Both craft use proprietary “lntelligent” LI-ion batteries that have a capacity for roughly 10-20 minutes of flight and are legal for airline carry-on. Remaining battery capacity is displayed in the app for worry-free flight management.
Video modes (4K, 2.7K, 1080p) at different frame rates and ISO are selectable via the app. The X3 on the Inspire and the P4 camera have a fixed f/stop of 2.8. Therefore, in order to adhere to the 180-degree shutter rule for video (this provides the most pleasing motion blur), ND filters of varying strengths are necessary to account for bright light conditions, such as at mid-day. I have a set of ND4, ND8, ND16 and ND32 filters to keep shutter speed in line with the 180-degree rule (1/60th for 30p, 1/50th for 24p, etc.). ISO in low-light situations can be increased but will introduce higher noise levels that are difficult to process without loss of resolution. This is more apparent on the smaller sensor of the X3/Phantom 4 cameras.
I typically set AWB, manual shutter, and the appropriate strength ND filter to keep the exposure constant with the aid of an available histogram in the app. Overexposure zebra patterns can be selected in the app. Focus for the X3 and P4 lenses are set at infinity by the manufacturer, which will provide acceptable depth of field for almost all situations, as the craft is typically not close enough to any objects to render them out of focus. With the X5/X5R gimbals on the Inspire Pro, however, complexity increases, as the interchangeable lenses have selectable f/stops that will require more careful selection for required depth of field, especially at the long focal lengths. Perspectives for these lenses (multiply the MFT focal length x 2 for equivalent 35mm) range from medium-wide angle (12 and 15mm) to normal (25mm) and medium telephoto (45mm).
Still image capture does not require application of the 180-degree rule, so higher shutter speeds will ensure sharper images. The GO app enables multiple auto-exposure bracketing in high- dynamic range situations, as well as time-lapses. Third-party apps available for both craft also offer automatic shooting sequences that can be combined to create large panoramic files. This is possible in manual shooting as well, provided one uses sufficient image overlap. Unlike the GoPro fisheye look, the DJI lenses are rectilinear and have a minimum amount of barrel distortion. The RAW files enable lens distortion correction, with both Photoshop and Lightroom having DJI lens profiles embedded.
I typically set my craft and gimbal settings in the GO app to provide for smooth craft control (at the expense of speed performance and maneuverability). I set gimbal settings so as to have slow, smooth changes in gimbal tilt and pan. Experiment with what works best for your style of shooting.
In my next article I will be discussing some craft maneuvers and camera moves that produce effective and dramatic footage from an aerial perspective. In the meantime, fly safe!
Ralph Bendjebar is a resident of Minnesota who retired from Northwest Airlines in 2007 as an Airbus 330 Captain. He currently works part-time for Boeing as a B-787 flight instructor. Ralph’s photography career started with an avid interest in landscape photography that morphed into a further interest in wildlife. He loves photographing big cats on photo safaris, and his most recent trip in January 2016 was to his favorite location, the Serengeti. Ralph’s email address is email@example.com