when you are considering buying a drone you may have a specific case in mind. Whether or not you like landscape photography or you are looking to observe and explore things in the distance you may wonder how far can a drone camera see? There are a wide range of variables which determine how far a drone camera can see but, ultimately, it comes down to the amount of pixels per foot the drone camera is able to detect at different distances. I have calculated the recognition, classification, and detection distances of drone cameras from 720p all the way up to 8K.
An average drone camera operating at 1080p can recognise people up to 50 ft away. Between 50 and 100 ft, the camera is able to classify objects (such as people or animals or cars) past 100 ft the camera is only able to detect movement and cannot determine objects or recognise individuals.
In this article, we will go over everything you need to know about how far a drone camera can see and you will find out the distances over which drones are able to recognise people, classify objects, and simply detect something in the distance. It may surprise you as to how far drone cameras are able to do this.
If you want to get a better understanding of exactly what a drone is able to see at 400, 300, 200, and 100 feet in height you can watch this YouTube video which perfectly demonstrates the sorts of things that a drone can see at various vertical heights.
In this article, we will be looking at the distances over which drones are able to recognise and classify objects. This is because at these distances the drone is able to impact on security of individuals as well as provide surveillance of specific objects and locations.
Pixels Per Foot (PPF)
In the security world, there are three levels of classification for footage. The footage can be classified as being able to recognise individuals all the way through to simply detecting movement.
A drone camera has a very wide field of view and whether or not you can actually readily identify a person or it is just a featureless blog on your video depends on the size of the subject in the recorded image.
The standard measurement for the size of an object on a recorded video is pixels per foot (PPF). The pixels per fit is a measurement of quality of the final video based on the size of the area the video is recording. Here are some common qualities and number of pixels horizontally and vertically.
|Camera Classification||Number of Pixels (horzontal)||Number of Pixels (vertical)|
I have calculated the number of pixels per foot of each common resolution of drone camera at various distances. Most cameras are capable of 1080p and 4K footage and some of the more advanced cameras can see up to 8K (Like the Autel Evo 2 Series).
Here is the table of pixels per foot at various distances for various cameras. I have colour-coded the distances with green, yellow, and red which signifies the recognition, classification, and detection distances that each drone is able to achieve.
We can see that the higher the solution of the camera the further that it can recognise individuals from a scene. For example, an 8K camera can identify people at approximately 150 foot in distance. Whereas, a 1080p camera quickly loses recognition distance and can only classify subjects at 50 foot and cannot pick out any identifying features past 100 foot from the subject.
This is also presented in the graph, below, of the same data.
Let’s take a quick look at the three levels of footage classification and how do they relate to the data that I have presented.
The three levels of footage classification
Drone cameras can see very far into the distance. Their unique vantage point – from very high in the sky – can give them an un-obstructed view of large area. However, even though the drone can see that distance it may not be able to actually recognise any person or identify any object.
Here is a rundown of each of the classifications used in the security industry and the most important factor is the pixels per foot.
The highest classification of pixels per foot is the recognition classification.
This is 60 PPF in day time and 90 PPF at night.
In this classification you are able to directly identify features on a person such as facial features, logos on clothing and license plate numbers on cars.
For security reasons this is the most useful type of video as it identifies a lot more about an object. The issue with getting this type of quality with a drone is that the drone is very loud and hovers closely to the subject.
This means that it is unlikely that a drone would be able to record this level of footage of you without you being aware of the drone’s presence.
Typically, a drone has to be within 5 foot of you to identify you if it has a 720p camera and it can recognise you at 4K at a distance of 50 feet away from. Here is a table where I highlight the distances at which different resolution cameras can recognise you.
|Camera resolution||Distance (foot)|
The next level of classification is where the camera is not able to pick up individual traits but can classify the object.
in this section of classification the footage is able to identify aspects of you and the object. For example, it is able to identify your gender, race or ethnicity, the colour and types of clothes that you are wearing and it can also distinguish the make and model of the car.
This is at 40 PPF in the day time and 60 PPF at night.
A drone is able to fly a little bit further away from your location but it is likely that you will still be able to hear the propellers in the distance and you will be aware that a drone is in the area.
Typically, a 720p camera will be able to classify you at approximately 50 foot whilst a 4K camera is able to classify you from approximately 100 ft away. Here is a table of distances for different resolutions at which a drone camera can classify subjects in the footage.
|Camera resolution||Distance (foot)|
The last definition and classification of footage is called detection.
Detection is the lowest form of footage classification and you are able to see activity that you are not able to pick out individual details of a person or a car. For example, you will be able to see a person or car move in the image that you will not be able to identify any features about that subject.
This is at 20 PPF in the day time and 40 PPF at night.
It is possible that a drone is able to collect these sorts of images of you without your knowledge. This is because the drone is able to fly up to 350 foot away from your current location and still be able to pick out and detect movement in the scene.
This sort of footage is the less important for security reasons since it is not able to personally identify people or objects.
Typically, a 720p camera is unable to make out details at a distance of approximately 100 foot whilst a 4K enabled camera is not able to resolve anything in the image from a distance of approximately 200 foot. Here is a rundown of the detection limits of cameras of various resolutions.
|Camera resolution||Distance (foot)|
You can see that this distance is dramatically higher than the other classifications and after this distance the footage gets worse and worse.
What determines how far a drone can see?
Even though I have focused on the resolution of the camera there are a number of factors that go into determining how far drones can see in the real world. Given perfect conditions the numbers, above, make perfect sense. However, there are very few instances where the perfect conditions exist and here we will explore what determines how far drones can see.
Moving closer to objects
The first thing about a drone is that it is not a fixed entity. That means that it is able to quickly move towards an object if it wants to see more details. If you have 8K camera you don’t have to get particularly close or move particularly far if you want to move from classification to recognition distance.
If a drone wants to make out more detail about a particular area of the scene they are able to simply fly towards object to quickly improve the resolution and usefulness of the footage.
Field of view
There are many different types of cameras with a variety of fields of view. Because the primary metric is the number of pixels per foot a wide field of view quickly limits the number of pixels per fit in the image.
A wider field of view is much better for landscape drone photography and videography but will not enable the drone pilot to make out as much detail. On the other end of the spectrum, if you’re drone camera has a very narrow field of view you will be able to make many more features and the classification and identification of people and objects in the image will be much clearer and easier.
Drone cameras have improved significantly over recent years. There are a number of drones on the market which include optical zoom capabilities. This means that you are able to optically zoom into the scene and allows the drone pilot to increase the resolution of a particular area.
Some popular drones are able to zoom up to 4 times which can quickly increase the number of pixels per foot in the image.
The DJI Mavic air 2 has a 4 times optical zoom and it was tested thoroughly by nofilmschool.com and you can see the video, here:
Cameras are able to switch between multiple modes. The highest resolution camera on the market at the moment is an 8K camera. This has up to 16 times more pixels compared to HD and four times as many pixels compared 4K. The higher the resolution of the camera the higher the number of pixels.
This enables the pilot to deeply zoom into a scene, crop and image without any loss in quality whilst also retaining the colour depth profile.
The amount of light that is getting into the camera is one of the most important features of determining how far a drone can see. There are many drones that do not operate well in lowlight situations. However there are drones with night vision which you can check out my other article – click here.
Quite simply, drones operate much better when there is a significant amount of light entering the lens and making its way to the sensor. As soon as this is impacted the quality of the footage diminishes significantly and the ISO setting of the drone needs to be increased. This setting increases the sensitivity of the drone to the incident light which can introduce a lot of noise into the image.
Type of camera
Lastly, the type of camera that a drone is able to carry has diversified in recent years. How far a drone can see not only depends on the number of pixels per foot of the image but it also depends on the type of camera it is carrying.
This can include thermal imaging and night-time cameras as well as lidar for 3D imaging and cloud point imaging of objects and infrastructure.
We are most familiar with drones carrying an optical camera but it is not limited to this.
In this article, we have discussed how far a drone can see and I have performed a number of calculations to understand exactly how distance impacts the sorts of features a drone can see for various drone camera resolutions.
Ultimately, it is likely that if you are being filmed by a drone and you are aware of it it is able to classify some aspects of your person such as your clothing and ethnicity. However, for it to be able to identify you individually it has to get very close which is unlikely to be a stealthy approach.
Frequently asked questions
Here are some frequently asked questions about how far drones can see.
How far can drones see at night?
The distance a drone can see at night is significantly limited by the lack of available light. Unless the drone has nightvision it is unlikely to be able to see past a few feet. In lowlight conditions, the drone may be able to identify a person at 100ft.
How far can a military drone camera see?
Because military drone cameras are incredibly high resolution it is likely they are able to see and recognise people from a much greater distance than civilian drones. Based on my calculations, it is likely that they will be able to classify people and objects at a distance of 500 ft or greater.
This very much depends on the ability of the drone to get direct line of sight and plenty of light into the camera.
Can drones see inside your house?
Drones can only see inside your house through a window. It’s actually very difficult for a drone to be able to look directly into the window and make out the entire room. It is likely that they will only be able to pick up objects and people standing window.
Thermal cameras are able to identify hot houses and heat leakages by looking at the infrared part of the spectrum. This will be able to give the viewer an idea of your house and could potentially indicate what is inside the house. For example, police tend to use thermal imaging cameras on the roofs of suburban houses to detect grow houses or other illegal activity.