The use of drones for aerial photography has grown rapidly over the past few years, and systems are now available in all shapes and sizes, ranging from small hobby aircraft to complex commercial systems.
Whether you’re a beginner just looking to have fun, or an experienced photographer exploring new creative opportunities, there’s never been a better time to try this technology.
If you’ve never flown one before, drones have the potential to be a bit intimidating. In this article, the first of a three-part series, we’ll familiarize you with the basic features and components that comprise most consumer drone systems. In parts two and three, we’ll talk about how to select the best drone to meet your needs, and what you need to know about safety before your first flight.
What’s in a drone system?
Let’s get some vocabulary out of the way. While it’s common to refer to a remote-controlled aircraft as a drone, you may also run into the terms UAV (unmanned aerial vehicle) or UAS (unmanned aircraft system), and professional pilots usually prefer to use these descriptors. The words drone and UAV are largely interchangeable as they both refer to just the aircraft, while UAS refers to the entire system. For convenience, we’ll use the word drone throughout this article.
Every drone system is a bit different, but there are some basic things most have in common. In addition to the aircraft, they’ll generally include a lithium polymer battery for power, a camera mounted on a stabilized gimbal, and a radio communication system. Most also include a dedicated controller, though some less expensive consumer models can be controlled using only a smartphone.
From the outside, most drones appear to be simple devices, but they’re actually built around some fairly advanced technology that makes them easier to fly. This includes GPS for tracking the drone’s position, various sensors to help avoid unwanted collisions, and intelligent flight modes that can automatically focus on a point of interest or track a moving subject.
That’s a lot, so let’s break it down!
The aircraft
At the core of any system is the aircraft, and most consumer and prosumer drones today are quadcopters (though there are exceptions). Today, all multi-rotor drone systems designed for photo and video use a fixed-pitch propeller system. Most models use removable propellers made from a plastic/fiberglass composite that have a simple twist locking system to hold the propeller in place. Alternatively, some will use a folding propeller system.
A twist-lock prop on the DJI Phantom 4 Pro (L) and a foldable prop on the DJI Mavic Pro (R).
The drone's propellers are driven by brushless motors that spin at very high speed to produce the thrust required to fly. Each motor has a corresponding speed controller unit that allows for slight adjustments in the speed of the rotor; by varying the speed of the individual motors relative to one another, it's possible to induce pitch, yaw, roll and altitude.
Flight controller
The flight controller is your direct line of command to the drone, and the two are linked using a radio control system, typically at 2. 4 or 5. 8 GHz. Input from the sticks on the flight controller sends signals to the aircraft directing it to adjust the speed controllers on each motor, allowing you to maneuver the drone. Additional inputs allow you to control the camera and other features specific to the model you’re flying.
The same radio signal used for command and control also allows the video signal to be fed from the drone to the controller’s screen, providing a real-time view for shooting photos or video. In many cases, the screen is just an Android or iOS device running a control app that you’ve installed and paired with the controller, though some models, such as the DJI Phantom 4 Pro+ and Yuneec Typhoon 4K, have their own built-in screens.
In addition to seeing a live video feed, the screen allows you to monitor telemetry from the aircraft and includes all the controls you would expect for photography such as custom WB, bracketing, shooting style, and other camera settings.
In addition to sticks to control the drone's movement, most flight controllers include additional inputs that allow for direct control of things like camera movement and shutter/record buttons. Numerous other functions are available through the touch screen.
Gimbal
If you’re planning to take photos or videos from the air, it’s critical that your camera remain as steady as possible. Most drones actually move quite a bit as they maneuver around or make corrections to maintain position. To compensate, the camera is mounted to a gimbal: a device that isolates it from the vibration and movement of the drone. Most gimbals use a 3-axis system that allows for yaw (rotational stabilization), pitch (holding the horizon during forward and backward movement), and roll (holding the horizon during side-to-side movement).
"Most drones actually move quite a bit as they maneuver around or make corrections to maintain position. "
Gimbals use brushless motors that are very precise, and hold the camera in place so that video and photos (including long exposures) look amazing. In fact, if you watch a drone flying in even a moderate amount of wind you’ll notice quite a few small movements, but with a good gimbal the camera’s image will be rock solid. Some systems also offer a dual operator mode that allows the pilot to fly, while a separate camera operator runs the gimbal. This is the ultimate mode for shooting video!
The gimbal isolates the camera from vibrations and small movements by the drone, providing a stable image.
Global positioning system (GPS)
Once your drone is in the air you want it to maintain its position, even in windy conditions. Though it’s possible for a skilled pilot to do this without assistance, all drones today rely on GPS technology, typically using both the Global Positioning System and GLONASS (the Russian GPS system), to automate this task with a high degree of precision.
The good news is that GPS makes it surprisingly easy to hold, fly a straight line, or orbit a subject while the computer does the hard work of making small adjustments to compensate for wind direction and turbulence, and as a result, drones are often much easier to fly than people anticipate. However, GPS, like any technology, can fail. As a result, learning to fly a drone without GPS assistance is an important skill to learn.
Collision avoidance systems
A big advancement over the past couple years has been the development of collision avoidance systems that use vision, sonic and infrared sensors to avoid obstacles. Vision systems can ‘see’ objects and halt the aircraft before it strikes something, however they usually have a limited range (15m/50ft), and the sun can sometimes create issues by causing them to think something is in the way when nothing is there.
"Vision systems can ‘see’ objects and halt the aircraft before it strikes something, however they usually have a limited range (15m/50ft). "
Sonic systems use sound (much like bats) to sense objects, and are usually aimed at the ground and used for auto-landing operations and ‘positioning’ on the ground in lieu of GPS. Finally, IR (infrared) sensors are a relatively new option and work based on reflected IR spectrum light. These are short range and have issues in low light, but work in a similar fashion to vision systems for obstacle avoidance.
The small circles that look like bug eyes on the front of the DJI Mavic Pro are visual sensors for the collision avoidance system.
What are all these systems used for? Mostly, assisting new pilots in preventing collisions with objects in their vicinity, as well as preventing a loss of aircraft when returning to home by allowing the drone to avoid trees or other obstacles. However, it’s important to remember that the pilot in command is always responsible for the aircraft. Collision avoidance systems are useful but not infallible, so don’t depend on them to keep you out of trouble!
Batteries
Let’s talk about power. Most drones use lithium polymer, or ‘LiPo’ batteries. These cells come in all sorts of shapes, sizes and power ratings. ‘Smart LiPo’ batteries have built-in charge/discharge regulators and sensors that can report battery voltage and temperature via an app or the press of a button. Typically, LiPo batteries run both the controller and the aircraft, and flight time usually ranges from approximately 15 to 30 minutes depending on your model, the conditions, and how aggressive you are at the controls.
LiPo batteries are energy dense and require special care, and can be dangerous if mishandled. Traveling with these batteries can be risky if you don’t take proper precautions, and in most countries, there are specific rules when you take these cells on airplanes.
"LiPo batteries are energy dense and require special care, and can be dangerous if mishandled. "
In the US, the TSA/FAA provide specific rules and instructions, which technically permit a LiPo battery to be placed in checked baggage when installed in its intended device. However, individual airlines may have more restrictive policies, and the best practice is to carry these batteries on the plane with you and not in checked baggage. If you’re outside the US, make sure you understand the rules in your country before traveling with LiPo batteries.
Intelligent flight modes
Originally, drones were simply a tool that allowed you to get your camera off the ground and into the air, but thanks to all the technology packed inside, modern aircraft can usually do much more.
"Intelligent flight modes make it possible to get very creative shots with minimal effort by the pilot. "
Many drones today include a variety of semi-autonomous (‘intelligent’) flight modes that use technologies like GPS, computer vision and subject tracking to help with more complex tasks. Common examples include the ability to actively track and follow a subject as it moves, orbiting around a point of interest, or programming waypoints for the drone to follow.
Intelligent flight modes make it possible to get very creative shots with minimal effort by the pilot. In a sense, it’s a bit like having a separate drone operator while you focus on the creative side of things. These modes are particularly helpful if your intent is to shoot video as they can make your footage look very cinematic.
One of the intelligent flight modes, waypoints (seen here), can turn your Phantom 4 Pro into a powerful surveying tool that has the ability to collect data like never before!
A word of caution, however. Don’t just take off and blindly start using these modes. They require good knowledge of how to disable them in case of an emergency, and should not be used by beginners until basic operation of the aircraft is mastered.
Who makes them?
There are numerous companies building consumer and prosumer drones today. The one most people will be familiar with is DJI, which is the 800-pound gorilla in the market. However, compelling models can also be found from companies like Yuneec, Autel Robotics, GoPro and Parrot, as well as a number of others.
Although it’s easy to lump these all into the same category, each creates different products and has different design philosophies. For example, Yuneec makes affordable hexacopters, and Autel Robotics provides options such a camera with thermal imaging capabilities in addition to visible light. In part two of this series, we’ll discuss how to go about choosing the drone that best meets your needs.
Conclusion
Drones are an amazing tool that allow us to do jobs remotely, safely, and in a way that doesn’t put a manned aircraft at risk. As technology advances the capabilities of these devices will only get better. If you’ve been looking for a way to bring a new perspective to your photos or video, consider taking to the skies. Just remember to fly respectfully and follow the rules in your locale – things we’ll discuss in upcoming articles.
. dpreview.com2017-8-3 16:00