Math help please - size and distance

[GadgetGuy]

I'll be just under 100', thanks

Camera makers express the field of view of a lens as the diagonal angle.
For the Mavic 3 main camera, that's slightly less than 84°.
The horizontal angle is approx 70.25°

With the 4:3 aspect ratio of the M3 main camera, at a distance of 380 ft, assuming level ground, at an elevation of 200 feet (half the height of your 400’ object) the photo will take in an area 400 ft high and 535 ft wide.

 

[MS Coast]

Thinking about this a bit more, it looks like for an 84 degree horizontal field of view and a image aspect ratio of 4:3, the vertical field of view would be about 68.2 degrees. So at a distance of 400', the view field would be about 720' horizontally x 542' vertically.

 

[veryzebra]

I just re-read the OP's post and better understood what he's asking. He wants to be at least 400' from the 400' tall object and want's to know how much of the screen would be filled vertically.

400' out from a 400' object means the angle to the top from ground level is 45 degrees. (Tan (45) - 1) If the vertical field of view of the main camera is 63 degrees the object will fill 45/63 of the frame. So just a bit more than 70%.

Thanks. Appreciate all the info from everyone. I'm leaving tonight to drive up (6 hour drive) and will be there in the morning. Just found out there is a landmark just inside 500' I can reference off of by aiming the gimbal straight down.

 

[Zbip57]

Oops, my bad.

I made a mistake in post#19 showing how to calculate the field-of-view angle of your camera. The FOV angle is actually twice the calculated value of θ in that example.

I edited a comment to the bottom of that post.

 

[GadgetGuy]

My head hurts!
If I had known how important trig might become to drone flying, I would have paid less attention to teacher and more to her lesson plans in 8th grade!

 

[dar1]

fwiw, the post above seems to be assuming that you can calculate vertical FOV by taking the known horizontal FOV of 84 and dividing by 1.33 (the 4:3 ratio) to get vert fov of 63. But the calculation isn't that simple -- there's a specific equation for converting between h and f fov's that includes a tan calculation (just google it, and here's an example of one of the many online calculators for this: Horizontal/Vertical FOV Calculator ). Using the correct equation, the vertical FOV would be 69, not 63. Also, some posts above seem to assume the 84 is vertical --- I seriously doubt that -- usually such specs are going to be for the wider horizontal fov that most people care about.

 

[PanoVolo]

fwiw, the post above seems to be assuming that you can calculate vertical FOV by taking the known horizontal FOV of 84 and dividing by 1.33 (the 4:3 ratio) to get vert fov of 63. But the calculation isn't that simple -- there's a specific equation for converting between h and f fov's that includes a tan calculation (just google it, and here's an example of one of the many online calculators for this: Horizontal/Vertical FOV Calculator ). Using the correct equation, the vertical FOV would be 69, not 63. Also, some posts above seem to assume the 84 is vertical --- I seriously doubt that -- usually such specs are going to be for the wider horizontal fov that most people care about.

typically lens spec and EXIF/XMP data contains diagonal FOV, not horizontal. However, the specification is not clear on that.

 

[Meta4]

fwiw, the post above seems to be assuming that you can calculate vertical FOV by taking the known horizontal FOV of 84 and dividing by 1.33 (the 4:3 ratio) to get vert fov of 63. But the calculation isn't that simple -- there's a specific equation for converting between h and f fov's that includes a tan calculation (just google it, and here's an example of one of the many online calculators for this: Horizontal/Vertical FOV Calculator ). Using the correct equation, the vertical FOV would be 69, not 63. Also, some posts above seem to assume the 84 is vertical --- I seriously doubt that -- usually such specs are going to be for the wider horizontal fov that most people care about.

Camera makers quote FOV for lenses as the diagonal angle.