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What drone pilots see while they are flying, are the low latency video from analog FPV cameras. To choose the best FPV camera for your multirotors, there are a few things to consider which we will discuss in this post.

Choosing FPV Camera

FPV camera is one of the most important parts of a quadcopter FPV setup. Real-time image from the camera is broadcast through a video transmitter. Regardless what video transmitter you have, the image you see on the FPV display is only as good as your FPV camera.

FPV Camera Size and Weight

The size and shape of the camera determine how easily the camera can be mounted in the given multirotor frame.

When the hobby just started, FPV cameras used to be built on a square 32x32mm PCB without any protection and they are called “board cameras”. Components in a board camera are completely exposed and can get damaged easily in a crash.

Later on, manufacturers decided to put the electronics inside a protective case which became the standard today.

The size of the camera is determined by the width – the distance between the two mounting holes on the sides. The available sizes are:

• Standard (28mm)
• Mini (21mm)
• Micro (19mm)
• Nano (anything smaller than micro – not standardized yet)

FPV Camera Sizes: Standard, Mini, Micro

A dedicated FPV camera can weigh around 4g to 20g.

There are also “AIO” (all in one) FPV cameras that has a video transmitter integrated. They have a very small form factor and extremely lightweight, however, they don’t give you very good image quality and range. These are usually designed for micro size drones such as the Tiny Whoop, and we don’t normally use them on bigger drones.

CCD and CMOS – The Types of Imaging Sensor

CCD and CMOS are two main types of image sensors in FPV cameras, each with unique characteristics and advantages.

CCD is an older technology and used to be the go-to image sensor for FPV cameras. Nowadays most new FPV cameras use CMOS and they are constantly getting better. Here is a summary of the pros and cons, for more detail check out this post about the differences of CCD and CMOS.

CCD

• Less jello effect in footage due to the global shutter
• Less digital noisy in low light
• Generally warmer color

CMOS

• Generally lower in latency (the good ones)
• Higher resolution, but also can have more digital noise
• More natural image color
• Low light / Night FPV cameras tend to use CMOS sensors
• Generally cheaper to make – therefore the cheapest FPV cameras are usually CMOS
• More susceptible to jello due to rolling shutter

CMOS cameras can perform just as good as CCD cameras these days, if not better. I am not talking about the $10 crap you can find on Banggood, but the brand name cameras like the Runcam Eagle or Foxeer Predator.

Personally, I don’t think it matters which image sensor you want to choose, as long as you like how the image looks. Make sure to check reviews before buying, see how they perform in different lighting conditions.

Aspect Ratio

There is 2 aspect ratio to choose from in FPV cameras, 4:3 and 16:9. Aspect ratio has nothing to do with resolution, it’s just the different screen shape.

16:9 vs. 4:3

4:3 is more square and has the shape of an old CRT TV while 16:9 is longer like a modern computer monitor.

One isn’t always better than the other, it all comes down to which ratio your FPV goggles or display supports. If you have a 4:3 camera, but your goggles is 16:9, the image will appear stretched. If you have a 16:9 camera but a 4:3 display, the image will appear squashed.

Aspect ratio isn’t directly related to the peripheral view, e.g. 16:9 camera doesn’t necessarily give you a wider field of view. It actually depends on the lens and image sensor of your camera, which we will talk about later.

But it’s worth knowing that CMOS sensors have a native aspect ratio of 16:9, while that of the CCD is 4:3. Some CMOS cameras allow you to choose between 16:9 and 4:3 in the setting, but the 4:3 is achieved by chopping off the sides from a 16:9 image, and therefore you will get a smaller field of view in 4:3.

Lens Size

FPV camera lenses are different in two main things: focal length and thread size.

Focal length changes the field of view (FOV) of the image, the lower the focal length, the wider the FOV. To give you some idea, here is a rough estimation:

Note that lens focal width DOES NOT equate to FOV.

FOV is a result of both lens focal length and sensor size. It’s actually important to know what FOV you personally prefer than knowing the focal width when you are buying a camera, as the sensor size can vary.

The wider the FOV, the more environment you can see which is preferred when flying proximity and racing. However, when FOV is too large, the image will get more distorted, which is known as the “fish-eye” effect. The objects in the middle will appear smaller and further away than it really is, while the edges of the image will appear curved and distorted.

I personally find 130-150 degree a good range for FPV, typically 2.1mm – 2.5mm lens.

This is a good example of different FOV (from narrower to wider).

You can replace the lens on an FPV camera to get a different FOV or image quality. In this article I experimented a few different lenses for the Runcam Swift, you can see how they make a difference to the image.

There are two thread sizes in FPV camera lenses: M8 and M12. M12 lenses are bigger but heavier. They are normally used in Mini and Standard size cameras. They let more light in, thus the image quality is usually slightly better than M8 lenses. M8 lenses are very compact and mostly used in Micro and Nano cameras.

Check out this article to learn more about FPV camera lenses.

Wide Dynamic Range (WDR)

Wide Dynamic Range (WDR) is a technology that aims to improve image detail under extreme lighting conditions where both bright and dark areas are present in the same frame.

WDR – Wide Dynamic Range of an FPV Camera

As you can see the image on the left it’s underexposed, you can see the sun and clouds very well, but the tree and bushes are all dark. On the right we have an image that is slightly overexposed, the trees are all visible now but the sky is blown out. The image in the middle represents the best wide dynamic range of the three images, you can see the clouds and the trees at the same time.

Once you understand the concept you will begin to appreciate the importance of WDR capability in FPV cameras because it helps you see better when flying. Most FPV cameras have some degree of WDR, but the WDR performance can vary.

Low Light Capability

If you plan to fly indoor, at sunset/dawn, or even at night, then you have to find out about the low light performance of an FPV camera. Some are designed more specifically for low light than others.

Here is a low light comparison of some popular FPV cameras I did recently.

The low light capability of an FPV camera is measured in LUX. The lower it goes the better it is for low light. For example, the Runcam Swift 2 has a minimum LUX value of 0.01, while that of the Runcam Eagle 2 is 0.0001, you know the Eagle 2 is going to be better at low light than the Swift 2.

Cameras with bigger imaging sensor also normally perform better in low light as more light enters the sensor.

Most FPV cameras come with day/night mode. It enables the camera to output either color and black and white images based on user’s selection, or lighting condition. “Night mode” makes use of near-IR light to deliver black and white images, allows you to see better in low light.

NTSC and PAL – Video Encoding Format

Does it matter which one to use? It does and it doesn’t.

The main difference between NTSC and PAL is in resolution and frame rate. PAL offers slightly better resolution, while NTSC allows higher frame rate. If you want to have a better picture, go with PAL. But if you want more fluid footage, NTSC does a better job.

• PAL: 720 x 576 @ 25fps
• NTSC: 720 x 480 @ 30fps

For a more detail comparison, check out this post.

Conventionally, NTSC is used in North America, Japan, and South Korea while PAL is used in most of Europe, Australia and large parts of Africa and Asia. It might be a good idea to stick with the standard in your country. But it really doesn’t matter nowadays, because both video formats are supported by all FPV equipment.

Note that you have to choose which format your camera is using in Betaflight OSD in order to have the text displayed correctly.

TVL – FPV Camera Resolution

TVL (TV Lines) is what manufacturers use to measure analog FPV camera resolution.

The number is based on how many alternating black and white lines can be displayed in the image horizontally. A 600TVL camera means it can display 300 black lines and 300 white lines alternately in one frame. The more TV lines, the better definition image you can get out of the camera. Commonly seen FPV cameras TVL are 600, 700, 800 and 1200.

However higher TVL doesn’t always give you a better image due to the limitation of analog 5.8Ghz video transmission, as well as your monitor or FPV goggles. For example, 1200TVL is not going to be twice as sharp comparing to 600TVL in an analogue FPV system.

There is no easy way to verify the TVL spec claimed by manufacturers. So don’t be overly concerned about this number when buying an FPV camera, and base your decision on the actual image quality.

Latency

It takes time for the FPV camera to capture and process the image before sending it to the video transmitter. The delay varies from camera to camera depends on its hardware as well as software.

Latency can be a deciding factor if you are into drone racing or high-speed flying. The lower the latency, the more quickly the pilot can react.

Imagine if you are flying at 100Km/h, a delay of 50ms (0.05s) means you quad will travel 1.4m before you can react on the sticks, which could mean the difference if you hit or miss the obstacle.

Latency is not something printed on the specifications, so I try my best to test as many cameras as I can, and provide this info to the community: FPV Camera Latency Testing.

Input Voltage and Wiring

The connection of FPV camera is very simple, there are usually only 3 wires: power, ground and video signal.  There might be more connections depend on camera features.

• Power
• Ground
• Video Signal
• OSD/Menu – to plug in the joystick for changing camera settings
• VBat/VSen – to connect to the battery and monitor its voltage
• Audio Signal – if your camera has a built-in microphone

Most cameras these days support very wide input voltage, e.g. 5V to 36V. This allows you to power them either from a regulated power source or directly from LiPo batteries (2S-8S).

I have some good practices on how to connect your FPV setup to get the cleanest possible video.

Camera Settings

You can access the camera menu and settings using a controller that comes with the camera.

Thanks to the effort by flight controller software developers, we can now even do this from our radio transmitter by hooking up your camera to the flight controller. This means you can change your camera settings anywhere without carrying a controller with you.

Here is the tutorial how to set up camera control via OSD pin.

Can I use HD cameras as FPV camera?

Those HD FPV videos you see on Youtube are captured using HD action cameras like the GoPro or Runcam 3, which is an additional camera pilot put on their multirotors.

Some of these HD cameras provide “video out” capability, and you can hook up to a video transmitter for FPV. But the latency is normally too high for FPV flying (typically over 100ms). You will probably crash before you can even see it.

Therefore I always use a dedicated FPV camera alongside with an HD recording camera. It’s also important that you don’t put the FPV camera on a gimbal, so it doesn’t mess up your orientation.

Adding “On Screen Display” (OSD)

This is a bit off topic, but i am sure there are beginners wondering what an OSD is. Basically, an OSD (on screen display) is a device that overlays text/data onto your camera footage.

OSD is a useful tool to have, you can display different types of data on your FPV screen, such as battery voltage, timer, RSSI, current draw and so on. Most flight controllers these days have built-in OSD so it’s become a lot easier to set up.

The source from https://oscarliang.com/best-fpv-camera-quadcopter/