How to set the length of the field of view?

I’m trying to set the camera scene so that the field of view will be a certain length. By the length of the field of view, I mean the length in meters that it would give me if I were to use the measuring tape tool and measure from one side of the screen to the other. Any ideas are greatly appreciated.

The field of view in meters depends on how far you are from the object you are viewing. For example, if you are 50 meters from a building and your FOV (in SketchUp) is 30 degrees, the following diagram shows the measurement in meters of the projected view:

Note that the FOV is calculated vertically and then scaled horizontally according to your screen ratio. The formula shown can be used to calculate the actual height (or use SketchUp to give you the numbers).

[added] Binoculars, for example, specify the field of view (at least in the US) as:

"Field of View: The field of view is simply a measure of how wide a piece of the landscape you see through a binocular. It can be expressed either in degrees or in the linear diameter (in feet) of the circular image visible in the binocular at a distance of 1000 yards."


If you know the distance to the target and want to know the FOV (in degrees) needed to frame a given height, the following formula can be used:

FOV = 2 * ARCTAN(H / (2 * D))

For example, if you are 100 meters (D) from a building that is 50 meters high (H) , the FOV is equal to 2 * ARCTAN(50 / (2 * 100)) or 28.0725 degrees.