Drone Glossary: 110+ Drone Terms Every Pilot Should Know

AGL (Above Ground Level)

Altitude measured from the ground directly below the drone, not from the takeoff point or sea level. The FAA's 400-foot altitude limit for drones is measured in AGL. If you take off from a hilltop and fly over a valley, your AGL increases even though you haven't climbed. Most drone telemetry displays show altitude relative to the takeoff point, which is not the same as AGL over varying terrain.

ATTI Mode (Attitude Mode)

A flight mode where the drone maintains its altitude and orientation using the barometer and IMU, but does not use GPS for position hold. The drone will drift with the wind. ATTI mode activates automatically when GPS signal is lost, which is why practicing in ATTI mode is recommended before flying in areas with GPS interference (near buildings, bridges, or mountains).

ADS-B (Automatic Dependent Surveillance-Broadcast)

A surveillance technology used by manned aircraft to broadcast their position, altitude, and velocity. Some advanced drones and ground stations include ADS-B receivers so pilots can see nearby manned aircraft on their controller screen. ADS-B is not required on consumer drones, but it is part of the broader airspace awareness system that Remote ID complements.

Autonomous Flight

Any drone operation where the aircraft follows a pre-programmed flight path without continuous manual input. Waypoint missions, orbit modes, and automated mapping flights are all forms of autonomous flight. Under current FAA rules, a pilot must still maintain visual line of sight and be able to take manual control at any time during autonomous operations.

B4UFLY

The FAA's official mobile app for checking airspace restrictions before flying a drone. It shows airspace classes, controlled airspace around airports, national parks, military zones, and active TFRs on a color-coded map. Free on iOS and Android. See our where can you fly a drone guide for a full walkthrough.

Barometer

A sensor inside the drone that measures atmospheric pressure to estimate altitude. Barometric altitude hold keeps the drone at a consistent height without GPS. Accuracy is typically within 1-2 meters but can drift with temperature and pressure changes. Most drones use barometer data as the primary altitude reference for hover stability.

Betaflight

An open-source flight controller firmware used primarily in FPV racing and freestyle drones. Betaflight runs on FC boards and handles PID tuning, motor mixing, and sensor processing. It is the most popular firmware in the custom FPV community, with alternatives including INAV (for GPS-equipped builds) and ArduPilot (for autonomous operations).

Bind-and-Fly (BNF)

A drone sold fully assembled and ready to fly, but without a transmitter (controller). The pilot binds the aircraft to their own compatible transmitter. BNF is common in the FPV hobby where pilots have a preferred transmitter they use across multiple drones.

Brushless Motor

An electric motor that uses electronic commutation instead of physical brushes to spin the rotor. Brushless motors are more efficient, more powerful, longer-lasting, and quieter than brushed motors. Every consumer drone above the toy category uses brushless motors. Motor size is described by a four-digit number (e.g., 2207) where the first two digits are the stator diameter in mm and the last two are the stator height. See our propeller guide for how motors and props work together.

BVLOS (Beyond Visual Line of Sight)

Flying a drone beyond what the pilot can see with unaided eyes. BVLOS operations currently require an FAA waiver or a visual observer chain. The FAA is developing a final rule to allow routine BVLOS flight for qualified operators, which would unlock commercial delivery and long-range inspection operations.

CBO (Community-Based Organization)

An organization recognized by the FAA that establishes safety guidelines for recreational drone flying. Recreational pilots who fly under CBO guidelines at designated fields have certain regulatory protections. The Academy of Model Aeronautics (AMA) is the most well-known CBO in the US.

Class B/C/D/E/G Airspace

The FAA divides US airspace into lettered classes. Class B surrounds the busiest airports. Class C covers medium airports. Class D covers smaller towered airports. Class E is controlled airspace at various altitudes. Class G is uncontrolled. Drones need LAANC authorization for B, C, D, and surface-level E. Class G below 400 feet is where most recreational flying happens. See our no-fly zones guide for full details.

Cinematic Mode (CineSmooth)

A flight mode on DJI and other consumer drones that limits maximum speed, reduces control sensitivity, and smooths out stick inputs for buttery footage. Cine mode typically cuts top speed by 50% or more and adds a gradual acceleration and deceleration curve. Useful for real estate, travel, and any shot where jerky movement would ruin the take.

Compass Calibration

The process of recalibrating the drone's magnetometer to account for local magnetic variation. Required when flying in a new location with different magnetic characteristics, or after the drone detects compass interference. The procedure involves rotating the drone in specific patterns. See our calibration guide for step-by-step instructions.

Course Lock

A flight mode where pushing the control stick forward always moves the drone in one fixed compass direction, regardless of which way the drone's nose is pointing. Useful for filming parallel tracking shots along a road or shoreline. Different from the default mode where forward means the direction the drone faces.

Crosswind

Wind blowing perpendicular to the drone's direction of travel. Crosswinds cause drift that the flight controller must compensate for, reducing effective battery life and maximum range. Most consumer drones handle crosswinds up to 10-12 m/s. See our flying in wind guide for wind speed limits by drone model.

D-Log / D-Cinelike

Flat color profiles available on DJI drones that capture more dynamic range by reducing contrast and saturation in-camera. D-Log M is the current DJI standard, while D-Cinelike is a lighter version with less flexibility but easier grading. These profiles preserve highlight and shadow detail for post-production color grading. Not recommended for pilots who do not plan to edit their footage.

ESC (Electronic Speed Controller)

The circuit board that controls the speed of a brushless motor by regulating the electrical current. Each motor has its own ESC. In consumer drones, ESCs are integrated into the main board. In FPV builds, ESCs are separate components (often combined as a 4-in-1 ESC stack). ESC firmware (like BLHeli_S or BLHeli_32) affects throttle response and motor braking behavior.

Failsafe

An automatic emergency response triggered when the drone loses connection with the controller, loses GPS, or encounters a critical sensor failure. Common failsafe behaviors include Return to Home (RTH), hovering in place, or landing immediately. Failsafe settings are configurable in most drones and should be reviewed before every flight in a new area. See our out-of-range guide for what happens when signal is lost.

FAA (Federal Aviation Administration)

The US federal agency that regulates all civil aviation, including drone operations. The FAA sets registration requirements, airspace rules, pilot certification standards, and enforcement actions for unmanned aircraft. Every drone flight in the United States falls under FAA jurisdiction. See our US drone laws hub for the complete federal framework.

Flight Controller (FC)

The central processing board that reads sensor data (gyroscope, accelerometer, barometer, GPS) and adjusts motor speeds to keep the drone stable and responsive to pilot inputs. The FC runs firmware (DJI's proprietary system, Betaflight, ArduPilot, etc.) that determines how the drone flies. In consumer drones, the FC is integrated and not user-accessible. In FPV builds, the FC is a separate component chosen by the builder.

Flight Time

The total time a drone can remain airborne on a single battery charge under real-world conditions. Manufacturer-stated flight times are measured in ideal conditions (no wind, constant hover, warm temperature). Real-world flight time is typically 15-25% less. Wind, cold temperatures, aggressive flying, and payload all reduce flight time. See our flight time guide for actual vs. rated times by model.

Fly-Away

An uncontrolled flight where the drone stops responding to pilot commands and flies in an unintended direction. Flyaways can be caused by compass interference, GPS glitches, signal loss, or firmware bugs. Modern drones with redundant positioning systems and RTH failsafes have made flyaways rare, but they still occur. See our lost drone guide for recovery steps.

FPV (First-Person View)

Flying a drone using a live video feed from the drone's camera, viewed through goggles or a screen, rather than looking at the drone directly. FPV is used in racing, freestyle acrobatics, and cinematic filming. Under FAA rules, FPV pilots must either maintain VLOS themselves or have a visual observer who can see the drone and communicate with the pilot. See our FPV goggles guide for current hardware options.

FRIA (FAA-Recognized Identification Area)

A designated area where drones without Remote ID capability can fly legally. FRIAs are typically indoor facilities or enclosed flying fields operated by CBOs or educational institutions. Outside a FRIA, all registered drones must broadcast Remote ID during flight.

Geofencing

Software restrictions built into the drone's firmware that prevent or warn against flight in certain areas. DJI's GEO system is the most common, creating restricted zones around airports, military bases, and other sensitive areas. Geofencing can be unlocked through official procedures (DJI FlySafe) for authorized operations. See our geofencing unlock guide for instructions.

Gimbal

A motorized stabilization mount that keeps the camera steady during flight by counteracting the drone's movement and vibration. Consumer drones use 2-axis or 3-axis gimbals. A 3-axis gimbal compensates for pitch (tilt), roll (side-to-side), and yaw (rotation). The gimbal is the single biggest factor in smooth aerial footage. See our gimbal overload guide for troubleshooting.

GIS (Geographic Information System)

Software and systems used to capture, analyze, and visualize geographic data. In drone operations, GIS is used in mapping, surveying, and photogrammetry workflows. Drone-captured aerial imagery is processed through GIS software to create orthomosaic maps, 3D models, and volumetric measurements. Tools like Pix4D and DroneDeploy are GIS platforms built specifically for drone data.

GPS (Global Positioning System)

The satellite navigation system used by drones for position hold, waypoint navigation, Return to Home, and geofencing. Most modern drones use multiple satellite constellations (GPS, GLONASS, Galileo, BeiDou) for better accuracy and faster lock. GPS accuracy for consumer drones is typically 1-2 meters horizontal, which is why precision landing uses downward vision sensors in addition to GPS. See our GPS drones guide for models with the best positioning.

Ground Effect

Increased lift and reduced power consumption that occurs when a drone hovers close to the ground (typically within one rotor diameter of the surface). The ground reflects the downwash airflow, creating a cushion of higher pressure. Ground effect makes low-altitude hovering more efficient but can cause instability during takeoff and landing on uneven surfaces.

Ground Station

A tablet, laptop, or dedicated device running mission planning software for autonomous drone operations. Ground stations are used in commercial mapping, surveying, and inspection work to plan waypoint missions, set camera triggers, and monitor flight progress. Popular ground station apps include DJI Pilot 2, Pix4Dcapture, and DroneDeploy.

Gyroscope

A sensor that measures angular velocity (how fast the drone is rotating around its axes). The gyroscope is the most critical sensor in the flight controller, providing the data needed to keep the drone level. Modern drones use MEMS (micro-electromechanical systems) gyroscopes that are small, lightweight, and extremely fast. Gyro data is sampled thousands of times per second in FPV drones to maintain stability during aggressive maneuvers.

Headless Mode

A beginner-oriented flight mode where control stick directions are relative to the pilot's position, not the drone's nose direction. Pushing forward always moves the drone away from you, regardless of which way it faces. Useful for new pilots who lose orientation, but it prevents learning proper yaw control. See our headless mode guide for when to use it and when to move past it.

Hover

Maintaining a fixed position in the air without moving in any direction. GPS-equipped drones can hover autonomously with minimal drift (typically under 0.5 meters). Non-GPS drones in ATTI mode will drift with the wind. Hover accuracy is a key spec for photography and inspection work. See our hovering guide for how different positioning systems affect stability.

Hyperlapse

A time-lapse video where the camera moves through space, creating a dramatic accelerated flythrough effect. DJI drones have built-in hyperlapse modes that automatically capture photos at intervals while flying a programmed path, then stitch them into a smooth video. Hyperlapse shots are popular for travel and real estate content.

IMU (Inertial Measurement Unit)

A combined sensor package containing accelerometers and gyroscopes that measures the drone's acceleration and rotation in three dimensions. The IMU is the core of the flight controller's stabilization system. IMU calibration is required when the drone detects drift or after significant temperature changes. Many commercial drones have redundant IMUs (two or three) for safety.

Intelligent Flight Modes

Pre-programmed flight behaviors available on consumer drones. DJI's intelligent modes include ActiveTrack (follow a subject), Spotlight (keep camera on a point while flying freely), Waypoint (follow a pre-set route), and MasterShots (automated cinematic sequences). These modes make complex shots accessible to beginners but still require pilot oversight and VLOS compliance.

IPX Rating

A standardized rating for water and dust resistance. IP67 means fully dustproof and can survive submersion in 1 meter of water for 30 minutes. IP43 means protection from objects larger than 1mm and light rain. Most consumer drones have no IP rating at all, meaning any water contact risks damage. See our waterproof drones guide for rated models.

LAANC (Low Altitude Authorization and Notification Capability)

The FAA's automated system for near-instant airspace authorization in controlled airspace. Available at roughly 900 US airports through apps like Aloft, DJI Fly, and AirMap. When you request LAANC authorization, the system checks your location against pre-approved altitude grids and issues authorization (usually within seconds) for approved altitudes. LAANC is essential for flying near any airport.

LiDAR (Light Detection and Ranging)

A sensor that uses laser pulses to measure distances, creating detailed 3D maps of terrain and structures. Some advanced drones (DJI Matrice series, commercial survey platforms) carry LiDAR payloads for surveying and mapping. Consumer drones like the DJI Mini 4 Pro use simplified LiDAR for obstacle avoidance. LiDAR mapping produces point clouds with centimeter-level accuracy.

LiPo (Lithium Polymer)

The battery chemistry used in nearly all consumer and FPV drones. LiPo batteries offer high energy density and discharge rates but require careful handling. Never charge unattended, never puncture or crush, and never discharge below 3.0V per cell (3.5V is the practical minimum). Store at 3.8V per cell (storage charge) when not in use for more than a few days. See our battery life guide for longevity tips.

Magnetometer

A sensor that measures the Earth's magnetic field to determine the drone's compass heading. Magnetometers are sensitive to electromagnetic interference from metal structures, power lines, and electronic devices. Compass errors cause erratic flight, circling (toilet bowling), or flyaways. Calibrating the compass before flying in a new location reduces the risk of interference issues.

MSL (Mean Sea Level)

Altitude measured from sea level, used in manned aviation and FAA airspace definitions. Class A airspace starts at 18,000 feet MSL. For drone pilots, MSL matters when flying at high elevations: if you are at 5,000 feet elevation, the 400-foot AGL limit puts your MSL altitude at 5,400 feet.

ND Filter (Neutral Density Filter)

A darkened lens filter that reduces the amount of light entering the camera, allowing the pilot to use slower shutter speeds for cinematic motion blur. The "180-degree rule" in video suggests your shutter speed should be double your frame rate (1/60 for 30fps, 1/120 for 60fps). ND filters make this possible in bright daylight. Common strengths are ND4, ND8, ND16, ND32, and ND64.

NOTAM (Notice to Air Missions)

Official notices published by the FAA to alert pilots of temporary conditions affecting airspace. NOTAMs include TFRs, airport closures, military exercises, and other changes. Drone pilots should check NOTAMs via the B4UFLY app or the FAA NOTAM system before any flight, especially near airports or event venues.

Obstacle Avoidance

Sensor systems (infrared, stereo vision, LiDAR, ultrasonic) that detect objects in the drone's flight path and either stop, slow down, or reroute around them. Modern consumer drones offer omnidirectional obstacle avoidance with sensors on all six sides. Obstacle avoidance does not detect thin objects like power lines or tree branches reliably. See our obstacle avoidance guide for models with the best sensor coverage.

OcuSync / O4 / O4+

DJI's proprietary video transmission systems. O4 (used in Air 3S, Mavic 4 Pro) transmits at up to 1080p/60fps with a rated range of 20km. O4+ offers improved interference resistance. These systems provide the live video feed to the controller and handle the control link simultaneously. Non-DJI alternatives include Caddx Walksnail and HDZero.

Orthomosaic

A georeferenced aerial map created by stitching together hundreds or thousands of overlapping drone photos. Orthomosaics are geometrically corrected so that measurements taken from the map are accurate. Used in agriculture, construction, mining, and surveying. Created using photogrammetry software like Pix4D, DroneDeploy, or Agisoft Metashape. See our photogrammetry guide for recommended setups.

Part 107

The FAA regulation (14 CFR Part 107) that governs commercial drone operations in the United States. To fly a drone for any business purpose, you need a Part 107 Remote Pilot Certificate obtained by passing a knowledge test. Part 107 sets the rules for altitude, speed, airspace, visual line of sight, and operations over people. See our Part 107 guide for the full certification process.

Payload

Any weight carried by the drone beyond its own airframe and battery. Payloads include cameras, sensors, LiDAR units, delivery packages, and accessories like propeller guards or lights. Payload reduces flight time, range, and wind resistance. See our payload guide for capacity by model.

Photogrammetry

The science of making measurements from photographs. In drone applications, photogrammetry uses overlapping aerial photos to create 3D models, orthomosaics, and topographic maps. The drone flies a grid pattern, capturing images with 70-80% overlap. Software like Pix4D processes the images into accurate spatial data. Used in construction, mining, agriculture, and environmental monitoring.

PID (Proportional-Integral-Derivative)

The control algorithm used by flight controllers to maintain stability. PID values determine how aggressively the drone corrects deviations from the desired attitude. P (proportional) controls immediate response to errors. I (integral) corrects persistent drift. D (derivative) dampens oscillation. PID tuning is essential in FPV builds and is handled automatically in consumer drones.

Pitch

Rotation around the drone's lateral axis, tilting the nose up or down. Pushing the right stick forward pitches the drone forward, causing it to fly in that direction. Pitch angle determines forward speed: steeper pitch means faster flight but more aggressive footage. Cinematic modes limit maximum pitch angle for smoother shots.

Propeller

The rotating blades that generate thrust to lift and maneuver the drone. Consumer drones use fixed-pitch propellers sized to match their motors. Propellers are labeled with dimensions (e.g., 9x4.5 means 9-inch diameter, 4.5-inch pitch). Always use the correct propeller orientation (CW and CCW props are not interchangeable). See our propeller selection guide and replacement guide.

QuickShot

Pre-programmed automated camera moves available on DJI drones. QuickShots include Dronie (fly backward and up), Helix (spiral ascent), Rocket (straight up), Circle (orbit a subject), Boomerang (oval path), and Asteroid (ascends, captures panorama, descends). Useful for social media content creation with minimal skill required.

Quadcopter

A multirotor aircraft with four motors and propellers. The most common drone configuration. Two propellers spin clockwise and two spin counterclockwise, allowing the drone to yaw (rotate), pitch, and roll by varying the speed of individual motors. Other configurations include hexacopters (6 motors), octocopters (8 motors), and tricopters (3 motors). See our propeller count guide for configuration comparisons.

Raw / DNG

An uncompressed or minimally compressed image format that preserves all sensor data for maximum editing flexibility. DNG (Digital Negative) is the most common raw format on DJI drones. Raw files require post-processing but allow recovery of blown highlights and crushed shadows that JPEG compression permanently destroys. Essential for professional photography work. See our RAW-capable drones guide.

Remote ID

An FAA-mandated system that broadcasts identification, location, and altitude data from a drone during flight. Required on all registered drones since March 2024. Standard Remote ID is built into newer drones. Older drones can use an external Remote ID broadcast module. Remote ID data can be received by law enforcement, the FAA, and the general public using compatible receivers or apps. See our FAA tracking guide.

Roll

Rotation around the drone's longitudinal axis, tilting the drone left or right. Moving the right stick left or right causes the drone to roll and move sideways. Roll is used for lateral movement, orbiting subjects, and sideway tracking shots. In FPV, aggressive roll inputs create the characteristic freestyle rolling maneuvers.

RTF (Ready to Fly)

A drone package that includes everything needed to fly: the aircraft, controller, battery, charger, and any required accessories. Most consumer drones (DJI, Autel, Holy Stone) are sold RTF. The Fly More combo variants add extra batteries, a multi-charger, and a carrying case.

RTH (Return to Home)

An automated function that commands the drone to fly back to its recorded home point (usually the takeoff location) and land. RTH can be triggered manually by the pilot, activated automatically when the battery reaches a critical level (Smart RTH), or engaged as a failsafe when signal is lost. The drone ascends to a pre-set RTH altitude to clear obstacles before returning. See our RTH drones guide for models with the most reliable return systems.

Sensor Size

The physical dimensions of the camera's image sensor. Larger sensors capture more light, produce less noise in low-light conditions, and create shallower depth of field. Consumer drone sensors range from 1/2-inch (budget) to 1-inch (prosumer) to Micro Four Thirds and larger (professional). The DJI Mavic 4 Pro uses a 2-inch sensor. Sensor size is the single biggest determinant of image quality.

Shutter Speed

How long the camera's sensor is exposed to light for each frame. Faster shutter speeds (1/1000) freeze motion but create a choppy "jello" look in video. Slower speeds (1/60) create natural motion blur but risk overexposure in bright light (solved with ND filters). For video, the 180-degree rule suggests using a shutter speed of double the frame rate.

Spotter (Visual Observer)

A person who maintains visual contact with the drone and communicates its position and surroundings to the pilot. Under Part 107, a visual observer can supplement the pilot's VLOS requirement. In FPV operations, a spotter is required because the pilot is looking through goggles, not at the sky. The spotter must be able to see the drone and communicate directly with the pilot at all times.

Sport Mode

A flight mode that increases maximum speed, reduces obstacle avoidance sensitivity (or disables it), and allows more aggressive stick response. DJI Sport mode typically doubles the top speed compared to Normal mode. Obstacle avoidance is disabled or limited in Sport mode on most drones, increasing the risk of collision. Battery consumption also increases significantly (20-30% faster drain).

Telemetry

Data transmitted from the drone to the controller in real time, including altitude, speed, distance, battery level, GPS signal strength, satellite count, and sensor status. Telemetry is displayed on the controller screen as an OSD (on-screen display). Monitoring telemetry is essential for safe operations, especially battery level and signal strength indicators.

TFR (Temporary Flight Restriction)

A temporary airspace restriction issued by the FAA for events like presidential travel, wildfires, disasters, space launches, and major sporting events. TFRs can appear with little notice and cover areas normally open to drones. Always check B4UFLY on the day of your flight. See our no-fly zones guide for TFR details.

Thrust-to-Weight Ratio

The ratio of a drone's total motor thrust to its total weight. A ratio of 2:1 means the motors can produce twice the force needed to hover. Higher ratios allow more aggressive maneuvers, better wind resistance, and faster acceleration. FPV racing drones have ratios of 8:1 or higher. Consumer photography drones typically have ratios of 2:1 to 3:1. A ratio below 1.5:1 makes the drone sluggish and unsafe in wind.

Tracking / ActiveTrack

A camera or flight mode where the drone automatically follows a moving subject using visual recognition, GPS, or a combination. DJI's ActiveTrack can follow people, vehicles, and animals while avoiding obstacles. Accuracy depends on the subject's speed, size, contrast against the background, and whether obstacle avoidance can keep up. See our follow me drones guide.

TRUST (The Recreational UAS Safety Test)

The FAA-required knowledge test for recreational drone pilots. It is free, taken online through FAA-approved test administrators, and takes about 30 minutes. The certificate never expires. TRUST covers basic safety, airspace rules, and your legal obligations as a recreational pilot. You must carry proof of completion (digital or printed) when flying.

UAS (Unmanned Aircraft System)

The FAA's official term for a drone and its associated equipment. The "system" includes the aircraft, controller, any ground station, and the communication links between them. "Drone" and "UAS" are interchangeable in casual use, but FAA regulations use "UAS" or "unmanned aircraft" exclusively.

VLOS (Visual Line of Sight)

The FAA requirement that the pilot or a visual observer must be able to see the drone at all times during flight, with unaided eyes (corrective lenses are fine, binoculars are not). VLOS is a fundamental rule that applies to both recreational and Part 107 operations. Maximum VLOS distance depends on the drone's size, color, and lighting conditions, but is typically 1,500 to 2,500 feet for consumer-sized drones.

Vortex Ring State (VRS)

A dangerous aerodynamic condition where a drone descends into its own downwash, causing turbulent airflow and a rapid, uncontrollable descent. VRS occurs when the drone descends too quickly (typically faster than 1.5 m/s) in still air. Recovery requires moving the drone forward or sideways to exit the turbulent column. VRS is rare in normal flying but a real risk during aggressive descent or in confined spaces like wells or elevator shafts. See our landing guide for safe descent techniques.

Waypoint

A GPS coordinate that defines a point along a pre-programmed flight path. Waypoint missions allow the drone to fly automatically between set points while the pilot monitors and adjusts camera angles. Used extensively in mapping, surveying, and repeatable inspection flights. Most consumer drones support basic waypoint missions through their companion app.

Yaw

Rotation around the drone's vertical axis, spinning the drone left or right. Controlled by the left stick (mode 2 transmitters). Yaw allows the pilot to change the drone's heading without changing its position or direction of travel. Smooth yaw combined with forward flight creates panning shots. Yaw speed is typically measured in degrees per second.

Zoom

The ability to magnify a distant subject. Drones offer optical zoom (physical lens movement, no quality loss) or digital zoom (cropping and enlarging, with quality loss). The DJI Mavic 4 Pro offers 7x optical zoom. The Air 3S has a dual-lens system with a telephoto option. Optical zoom is preferred for inspection, surveillance, and wildlife photography where getting closer physically is impractical. See our zoom camera drones guide.