Having recently started playing DCS I finally looked into cheap headtracking solutions because I didn't want to spend tons of money on an expensive IR (infrared) tracking setup and I also didn't want to wear reflectors or LEDs on my head because that's just silly.
Imagine my surprise when I learned that I didn't need to buy anything and that I already had all the hardware needed to get perfectly adequate head tracking: An old USB webcam. Alternatively, a phone's camera can be used as a webcam on your PC with which is free in the base version which is all you need. (I'm sure there are similar apps for iPhones. If you have an iPhone with FaceID, that basically is a built-in IR head tracker and you can utilize this hardware to get even better head tracking, although I haven't looked into that since I don't have one).
But wait, how could that possibly be as good as the expensive IR solutions?
The answer is simple: Magic Neuralnets. (Also the IR stuff is probably still a bit better and more accurate but this is by far good enough)
Using the free and open source and selecting its neuralnet tracker as input device (and fiddling with the curves for quite a bit) I now have reliable and accurate head tracking in DCS and ED.
Let me tell you: It is an absolute game changer, especially in dogfights where you can keep your eyes on the enemy at all times. I think I immediately became better at dogfighting because of this. Even just flying in supercruise is so much more immersive when you can look at planets and stars when you do fly-bys. Also helps when mining since you can basically scan the entire plane in front of you and find glowing asteroids much more easily when using the scanner.
Here are my settings (although they will be different for you depending on your webcam model, position and distance. Mine is on top of my 50" TV that I use as a monitor on my desk and it's looking down at me, so right off the bat I need a very big pitch offset to compensate for that. Ideally the webcam would be on the same level as your face and parallel to it. It's not a big deal if it isn't though, just make sure it's centered in front of you (yaw should be at 0 if you look straight ahead)
First, set up the Input, Output and Filter options like this and then press the big Options button:
This tab is where you adjust the offsets depending on your setup. Here you can also disable axis you don't need or map them differently. For ED I'm only using pitch and yaw. For DCS I'm also using X (left and right) as well as Z (forward and backward). Y (up and down) is handled in-game with the seat height adjustment so I don't need that. These values will change depending on the curves you set under Mapping, so adjust these later:
In this tab you can adjust the smoothing and deadzone of your movements. You can play around with these values to get a good balance between accuracy and responsiveness (it picking up the tiniest movement of your head and immediately moving your view in game) and image stability:
And these are the curves that will determine how your head movements are translated in-game. This is where you'll be spending a lot of time if you really want to fine-tune it and get it to respond exactly how you want to, but these settings should give you a good starting position:
Try it out, let me know your experiences and if you have any questions. Also let me know if you'd maybe like me to make a video explaining all this stuff in detail.
Happy tinkering!
