CameraTracker/Film gate settings for drone

I am working with this stock drone shot (https://www.storyblocks.com/video/stock ... orin20ghnv) with no metadata info on camera/focal length etc. and have tried a variety of CameraTracker/Camera settings in the hope of hitting on a combo that delivers a reasonable track...but with very little success. It is probably a reasonable assumption that it may have been shot on a DJI MavicPro. DJI specs are FOV 78.8° 28 mm f/2.2 Roughly equivalent to 35 mm.

How do I convert this (or make an educated deduction) for the Focal Length / Film Gate / Aperture Width /Aperture Height / Resolution Gate Fit settings in the Camera tab in CameraTracker?

I don't think estimating these options will make a difference for this shot. The enormous lens flare will make auto tracking difficult, giving the auto tracker items to track that have no correlation with the environment. The fact that there's a moving train doesn't help either. And the pretty wide angle distortion complicates matters even further.

So even if you had all the other info this would probably a hassle to track.

I do know that there are some very knowledgeable people on here who do a lot more tracking than I do, but this appears to be a very hard shot regardless.

Yeah I'm also pessimistic if the Fusion Tracker is the right choice for this. It's quite capable but there is a huge area you have to mask out. The water, the train and much of the lens flare.
This doesn't leave that much space and parallax for the auto tracks.

Supervised tracking could probably get you to something usable. Blender has free supervised tracking. Although I have given up on using it myself. I know many people love it and swear that it's one of the best camera solvers out there. I personally haven't received any good results with it yet. Probably due to the fact that I never actually used blender and give up on it quite frequently. I just can't get used to it.

The other question you should ask yourself is, do you need a 3D solve? If you just add some text into it, track a part of the bridge in the same depth as your text and animate the perspective change by hand (or connect it to a Text3D x and y position)

I’d also suggest looking at some tracking software which allows supervised tracking. Throw in 10 or so well placed feature tracks and it should be good, because shot itself seems very straightforward tracking wise, and to me looks like it doesn’t have very much lens distortion either. Wide angle aspect itself makes no difference to solver, wides are easier to solve than teles anyway.

Hey,
Since I'm into that on a yearly basis, I just participate with something which may help...

Well, lens flares indeed lower your chance to take anything in this shot, you'll have to be very picky. Here's how I'd try to manage it (with Mocha Pro) :
1/ focus on the top of the far mountain top and cliff on the right and on the left; select this first
2/ ditto with the boats on the bottom right, moreover it will help for parallax since it's on another plane
Make as large as possible mattes, though avoiding any occlusion with flares or reflection

That done, if not relevant enough, use the technique which consists in unlinking the matte from the track (I don't know how to do specifically on anything else than Mocha, I'm sorry) : this way you can track blurry stuff or remote horizon with the surface track not moving though recording keyframes of the movement of the cam...

Difficult to tell without testing

Hey
I found a reference of the last part of my post above :
https://borisfx.com/videos/mocha-unlink ... placement/

Thanks all for the input. Agreed, a clip with lots of challenges. After many attempts with various combinations of matting the bridge/river/sun flare, I managed to get a somewhat decent track. But then, as suggested, retried in Blender (sadly no budget at the mo for Mocha) , manualy managing each tracking point with much better results.

However, my question still stands. Davinci Resolve Manual states: "If the film gate is incorrect, the chances that the Camera Tracker correctly calculates the lens focal length become very low." I'm curious to know if there is some formula to calculate the right inputs for the Camera tab for the many devices that don't appear on the (somewhat limited) CameraTracker/Camera/Film Gate preset option list, especialy 35mm simulating devices: drones, phones, compacts etc etc.

Usually you find the sensor size online. Often it's in mm and Fusion wants inches so you have to convert it.

Problem with numbers from the net is that theoretical values and real values are not the same. While sensor sizes usually are correct, given that all the possible crops and so on are taken into account, lens focal length values are at best approximations. Even high quality prime lenses rarely have actually the same value as printed on its side. 35mm lens can easily be 32, 37 or some other random value. For matchmoving where one strives for RMS in single digits, it is about as good as totally random number. Constraining solver to wrong value will give worse solution, so use it as a hint/seed, but not hard constraint if possible (depends on software).

Only real way to get exact lens fov and focal length is to accurately solve a known reference scene and let solver calculate the fov.