The angular field of vision (often called FOV) is a measure of the angular size for an image made by a camera. Different video cameras have various FOV.Sketches Spring 2015 key, ipad

But which cares, right? I care. I care due to the fact that it matters when you are using a cam to gauge angles. Really, this relates to angular dimension. Allow’s consider a honey bee in an example image.

Sketches Spring 2015 key, mobile phone

If I know the camera’s field of view, I can utilize this image to locate the angular dimension of the bee. When I have the angular dimension (I will call this θb), I can utilize the complying with relationship.

 

Just split the size of the bee (L) by the range from the bee to the electronic camera (r) as well as you needs to get the angular dimension of the honey bee (in radians). Think regarding it. Suppose I took a whole lot of and also made them into a circle focused on the electronic camera? During that instance, the length of all of these honey bees would certainly be the area of a circle (2πr). If I split this by the distance (which is additionally r), I get an angular size of 2π. View it works. Ok, there is one little problem. If a things has an extremely large angular dimension, you do not acquire the size of that object considering that different parts of the object will in fact be different distances from the video camera. Still, it works in many cases.

Now for an experimental method to figure out the angular field of vision for the iPhone 6. Why not just look this up? Two factors. First, I do not consistently count on camera specs – especially when they aren’t so simple to discover. Second, the experimental technique is simply fun.

Here is the plan. Look at a number of objects of a recognized dimension and known range and make a graph (instead of just one object at one distance). I will certainly take this discussion board as well as adjusted it at various distances from camera.

Screenshot 5 13 15 1 45 pm, apple

If you wish to do something such as this yourself, below is a handy idea. The ceramic tiles on the flooring are often typical dimensions. In my office, they are 12 inches by 12 inches. I can just place the camera on one edge of a ceramic tile and count tiles for the range. I will certainly now tape-record two things for each picture: the range from the camera to object and also the angular dimension of the things. But below is the many things – I do not know the angular dimension. Rather, I will certainly measure the proportion of the object’s angular size to the field of vision for the video camera. I will call this α such that:

 

Where s is the size of the object as a ratio of the pixel size to the pixel dimension of the photo. Now for the information. This is a story of s vs. r.