Technicalities wise, most drones tend to look much the same these days. They all tend to have:
– An even number of motors – no less than 4, and if you have 6 or more, a motor can fail and you can still maintain control of the drone.
– A central hub where the drone’s brain / flight control electronics lives.
– An equal number of clockwise and anti-clockwise rotating propellers. If they all rotated in the same direction the drone would spin uncontrollably in the opposite direction – by having equal numbers of clockwise and anti-clockwise propellers, their torques cancel out.
– One or two Lithium-Polymer (‘LiPo’) battery packs powering the motors, and sometimes another battery powering additional components.
– A 2 or 3-axis camera gimbal which uses sensors and motors to keep the camera level no matter how the drone moves around it (although some simpler drones just have a fixed camera mount)
– Either fixed or retractable landing gear which keeps the drone away from the dust and dirt when landing and taking off from the ground.
Many of the more advanced drones now use GPS position hold technology to make them easier to fly. This basically means that if you don’t touch the control sticks whilst the drone is in the air, it will hover there all by itself, maintaining the same height and position in space until you tell it to do otherwise! This has been further expanded by some manufacturers who have implemented waypoint following features which allow you to use a Google Maps style interface on a smartphone or tablet to tell the drone exactly where to fly – you simply tap on a location on the map and the drone will fly there all by itself! Some drones even have a return-to-home button on their control handset too!
Most drones are designed to carry a particular range of payloads or cameras. The heavier the payload, the more batteries you have to carry to give a reasonable flight time, and the larger the frame, motors and propellers need to be to handle the additional weight. But that’s the beauty of the multi-rotor drone design which is so ubiquitous these days – if you need to carry a bigger camera you can just scale everything up and the mechanics and aerodynamics still work.
Typically the batteries weigh between 20 to 30% of the total weight of the drone, and this is based on achieving a flight time of about 10 to 20 minutes. Whilst this might sound quite short, it is actually plenty for taking aerial photographs from a number of different angles, and when one battery is depleted you can simply land, fit a fresh battery and take-off again immediately. Although it is possible to make a drone fly longer by fitting more batteries, you are then carrying more weight too! So adding a second battery will not give you twice the flight time, but perhaps only 60% more. The aspect of a shoot which uses the most flight time is when the client changes their mind about what angles they want once the drone is airborne! So for this reason it pays to plan ahead as much as possible whilst the drone is still on the ground – deciding exactly how the client wants their subject composed in the final images, what they want in the background, and so on.
Drones can generally fly in winds of no more than 15-20 mph, as above this speed the flight control and gimbal electronics will start to struggle to keep the drone stable. That said, the heavier the drone the better it will cope with strong winds, and some larger drones can still be flown in winds of up to 25-30 mph.