For example, OPTI has a built-in Optiflow Sensor (a downward facing sensor), which functions by picking out the patterns on the ground to ensure that the drone maintains a straight position.  ATTI, conversely, works a bit differently. With the ATTI, the drone employs other techniques apart from the external sensors to keep the drone in the right orientation and altitude. Thus, the drone can hover in place, or drift slightly around with the wind serving as a push. You will also find a GPS in some drones, and they help the drone to maintain coordinated and precise flights and landings.
When a new pilot tries to jump into the radio controlled aircraft scene, they may be tempted by a more expensive drone and while more expensive drones are usually easier to fly and have excellent cameras, the fact of the matter is that an inexperienced pilot just isn’t ready for all that. They aren’t ready to pilot a large, heavy aircraft, one which could very easily break, cause property damage, or even injury to another person. The smart thing to do in this situation is find a drone within a reasonable budget, so you can learn how to fly. That’s why today we’re bringing you this detailed guide of the best drones under $100.
Generally speaking, drones that cost less than $100 bucks aren’t worth your time. They’re flimsy, they lack advanced features, and they’re almost always squirrely as hell in the air. But Tello is different. Despite the fact that it retails for only $99, it boasts a boatload of high-end features and functionality. Under the hood you’ll find a 14-core Intel vision processing chip, flight stabilization tech from DJI, a 5 megapixel camera capable of shooting 720p HD video, and a battery that gets you 13 minutes of flight time.

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