GOPRO MOUNTING MATHS QUESTION

[wetny]

Hi, I want to mount the GOPRO on a pole at the side of the boat to capture it length but I am not sure how long the pole needs to be. The boat is about 25ft long and the camera has 170 deg field of view. Did anyone pay attention at school???

Cheers.

[MartinP]

With a 170 degree field of view you'll only need a 1 ft 2 inch pole to be able to fit in the full length of the boat assuming you're hanging the pole at right angles to the boat and are positioned in the middle. Double the length of the pole and the boat will fill half of the frame width...

[wetny]

Brilliant, thanks for that. How did you work it out?

[Simpo Two]

He might mean 1-2 feet not inches?

[MartinP]

Divide the length of the boat in half and make a right angled triangle from that and the pole (pole at 90 degrees to boat)
The angle of the triangle between the pole and hypotenuse is half the field of view (so 170 divided by 2 = 85 degrees)
The remaining corner of the triangle is 180 - 90 - 85 = 5 degrees.
The length of the pole = tan 5 x (half the boat length)

[MartinP]

Simpo Two said:

He might mean 1-2 feet not inches?

Never liked imperial measurements!

14 inches

[The Moose]

Would be interested to see a snap of the rig when it's all hooked up.

Might be interested in trying something similar.

I must say, what do you do about the rig in that type of video?

[Simpo Two]

MartinP said:

Never liked imperial measurements!

14 inches

That makes a lot more sense than 'tan 5 x (half the boat length)'. I don't have a ruler with those on it



I got as far as drawing some triangles on an old envelope and recalling the schoolboy acronym SOHCAHTOA, but then went phut so guessed it...