Not a drone, no matter big or small, can take off in the winder of Harbin without any insulating measure.

Every so called monster on the market becomes weak in low temperature environment:
You must push the control sticks gently, in case the drone falls due to a sudden voltage dip.
Flying with fear, before you hear the warnings to return to home after a few seconds flight…

Until the birth of Inspire 2, who claims its batteries can be self-heated and deal with temperature as low as -20℃.

So we buy one, bring it to the north of China and see whether the Inspire 2 performs just as how DJI claims.

Here are the results.

Performance test at ultralow temperature
Inspire 2
In -20℃,hot water turns to ice immediately when spilt into the air

Battery Performance 

Before carrying out the test, there is a question needs to be answered:

Can Inspire 2 take off in -20℃ without protection?

Just so you know:

In -20℃,an iPad dies in 5 minutes after turning on, and hands will stick with the Inspire 2 controller.

So what happens when putting a fully-charged battery into Inspire 2 without any insulating measures, in -18℃ environment?
Inspire 2
The recorded video clip has been speeded up
Inspire 2
Screenshot of DJI GO app during test
When the temperature was -18℃, Inspire 2 Intelligence Flight Batteries automatically heated to 13-14℃.

The self-heating function is triggered at -18℃ (the yellow numbers on the right side of the screenshot means batteries are heating),till battery cells’ temperature rises to 13-14℃. The heating process continues after take-off to keep the batteries at 14℃.

Our test showed that Inspire 2 can fly for 15-17min without being incubated before flight. The result has even better than Inspire 1’s 12min record at room temperature, without any accident like power failure.

Comment:

At the moment, even if some drones manage to take off in low temperature, most of them last no longer than several minutes, meaningless for aerial photography. But Inspire 2 successfully launched without any precaution and managed to fly with longer time and higher safety, making low temperature aerophotography a feasible thing, saving lots of troubles. It’s really a big surprise.

Maneuverability

Since Inspire 2 can perform normally in low temperature, it’s time to test its maneuverability.

How fast can Inspire 2 fly at -20℃

High-speed flight is difficult for drones in such a condition, because if you push the control sticks too hard, battery voltage might dip and cause danger to the drone. But excellent maneuverability is not only about acceleration and max speed, but also includes braking performance. What’s more, a good drone need to fly with great stability, without visible shakes.

To meet the above standards, we operated Inspire 2 to go up at top speed, fly close to the ground, slam the brakes in front of obstacles, hover in winds and one thing few drones can do—dive at full speed.

1. Full-speed Ascending
Inspire 2
Original images without any post-processing
Inspire 2 responded fast with huge propulsion at the moment of accelerating

Inspire 2
Full ascending process, at D-Log, without post processing

DJI GO showed the flight speed rocketed to 40.8km/h at the moment of acceleration, with vertical flight speed up to 5.8m/s. The footage not only shows the great propulsion, but also the extraordinary stability of Inspire 2.

2. Low-altitude Flight
Inspire 2
Original images without any post-processing
Inspire 2 kept the same altitude when flying forward at high speed.

Inspire 2
Full process, at D-Log, without post processing
Inspire 2 reached 90km/h easily.

When flying 1.5m above the ground, Inspire 2 accelerated to 85km/h within 6 seconds, and once reached 90km/h during the whole flight.

3. Manually Brake during Full-speed Flight
Inspire 2
Original images without any post-processing
Inspire 2 stopped stably in front of obstacles.

Inspire 2
Full brake process, at D-Log, without post processing

Drones need to brake fast to ensure safety. The image above recorded by Inspire 2 is smooth and stable, showing a fast and stable brake done by the aircraft.

4. Hover in Winds

Hovering in strong winds is a good way to test a drone’s maneuverability and stability. But in the weather where snow are blew away brook-like by strong winds, what Inspire 2’s performance will be?
Inspire 2
Original images without any post-processing
Look how stably Inspire 2 hovered in strong winds.

To make things harder, we let Inspire 2 rotate above the same spot.
Inspire 2
Original images without any post-processing
Rotating in strong winds, Inspire 2 caused a small displacement.

5. Diving at Full Speed

The last-but-not-least test to show a drone’s comprehensive performance: full-speed diving. The first thing we want to find out is whether Inspire 2 can achieve max speed horizontally and vertically at the same time, and the second is how fast it brakes after accelerating. This is a very dangerous action, and few drones dare to try it.

Due to limited propulsion, when Inspire 1 is diving, its vertical speed increase, but horizontal speed keeps unchanged or even decreasing. And because Inspire 1 cannot successfully brake during high speed flight. It’s seldom used in shooting diving footages.

Now take a look at Inspire 2’s performance.
Inspire 2
Original images without any post-processing
Inspire 2
Original images without any post-processing
Inspire 2
Full driving process, at D-Log, without post processing
Horizontal and vertical speed achieved the highest at the same time, and braked fast to ensure flight safety

When Inspire 2 is diving, its downward speed and horizontal speed are both increasing throughout the process. Horizontal speed keeps at about 90km/h (highest at 94.4km/h); vertical speed is about 9.0m/s (highest at 9.1m/s)

Both reached the official claim of 94km/h and 9.0m/s.

More importantly, Inspire 2 can brake fast and stably even at its highest speed, meaning its maneuverability is indeed greatly improved.
Inspire 2
Full driving process, at D-Log, without post processing

Once again Inspire 2 shows its great maneuverability by keeping horizontal speed at 90.5km/h and descending speed at 8.9m/s. Except a temporary jello effect appeared, might be caused by the liquid in damping balls was frozen in such a low temperature, weakening the damping effect.

Last we found a small bug, which is, Inspire 2 took 7 seconds to lift its landing gears, longer than 4 seconds in room temperature. The reason is the lubricating oil used to lubricate screws frozen due to low temperature, and increased friction.
Inspire 2
Original images without any post-processing

Comment:
1. The fact that one can push control sticks however he wants in -20℃ not only shows Inspire 2’s maneuverability, but more surprisingly, its resilience against low temperature.
2. There is no doubt a great improvement on Inspire 2’s acceleration and max flight speed, with higher stability and safety. “It feels great,” quoted one of our pilots.
3. Some small bugs did exist, but they didn’t affect the requirement of professional aerial photography in low temperature. Now professionals can use it to shoot faster and more visually impacted footages.

Spotlight Pro

How precise can Inspire 2 be in Terms of Image Recognition and Composition?

After going through the challenge of maneuverability in low temperature, let’s find out how its image processing system performs in the same situation.
The new Spotlight Pro in Inspire 2 mainly relies on VI technology and algorism, let’s see how they works in snowy weather.

First we tracked a static object.
Inspire 2
Inspire 2 moves stably from the front of the house to its side. Though the house looks tiny on screen, Inspire 2 always recognizes it and keeps it at the same place.

Next we tracked a target that was difficult to recognize.

Despite the target horse barely moves, its color is highly similar to the background, plus there are so many horses just like the one itself, it’s difficult for Inspire 2 to recognize.

Let’s see if Inspire 2 will make a mistake.
Inspire 2
Original images
Inspire 2
Original images

You can see when Inspire 2 comes close to the target slowly, it becomes bigger, and the shape also changes largely. And a telegraph pole appears in the video, failed to interfere Inspire 2’s constant focus on the same horse, though the position of the horse in the screen changes slightly.

Now let’s track a fast moving object.

When shooting a fast moving object, it’s recommended to use one of the two modes: Composition Mode. It’s particularly useful when you don’t have the time to frame your target. In Composition Mode, select the subject and the tracking position. When the subject enters the preset tracking position, press C2 button on the controller to begin tracking.

A car is approaching at about 50km/h.
Inspire 2
Inspire 2 managed to keep on tracking, despite the high speed and small size of the car.
Inspire 2
Inspire 2 accelerated from 60km/h to 70km/h. Even though it kept changing directions, the target was still at the center of the screen.
Inspire 2
During the tracking process, Inspire 2 came across some obstacles, including telegraph poles, but it still kept on tracking.
Inspire 2
The car changed its direction, and its movement was not predictable. But Inspire 2’s VI function still worked well to lock on the target

Comment:
1. The recognition precision of Spotlight Pro is very high, capable of tracking static as well as fast moving objects, even on a background that is almost the same with the target.
2. Successfully keeps locking on target with obstacles in its way.
3. Stability of composition still needs to be improved. Target has small displacement on screen, so gimbal control is still necessary in professional shooting.

Verdict

Good points:
Unprecedented low temperature performance

Faster acceleration and flight speed, higher stability and reliability
Strong maneuverability in low temperature
High precision in recognizing objects in Spotlight mode
High photosensitive property, with enough ISO to take night shots.

Weak points:
Longer time to lift and extend the landing gears in low temperature
Performance of hydraumatic damping balls are weakened in low temperature
Composition in Spotlight mode needs to be more stable

All in all, Inspire 2 is undoubtedly a monster for professional aerial photography in low temperature.

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