Field of View
The angle of view is the amount of a scene an optical system gathers information from. Or much simpler; how much a lens can see. When making photographs we need to take both cameras involved into consideration; your eyes and the expensive black box in your right hand.
Cameras (the type with a sensor or film); The field of view (FOV) of a camera has an amazing range if it has the ability to change lenses. Personally my bag has the angle of view range from 180 degrees to ~ 4.5 degrees (10.5mm fisheye to my 70-200 used with a 1.7X teleconverter (-note these are on crop sensors measured corner to corner)
Our eyes; 180 degree FOV corner to corner, undistorted.
This ones a bit more complicated, bear with me for a moment when I go Pythagorus on your ass; human vision covers about 160 degrees horizontally, and 130 degrees vertically, toss that into Pythagorus’ fun little math game you come up with 200 degrees diagonally. However we don’t see rectangularly, we have a more ovular field of view, so i rounded it down a bit. To give you the comparison a Nikon 10.5 fisheye covers 145 degrees horizontally, and 99 degrees vertically.
Long story short your eyes are always seeing more than almost every lens you will use, unless you start working with specialty lenses like the nikon 6mm which has a 220 degree field of view.
You see more than this image’s FOV (10.5 fisheye lens on crop sensor)
However, at the same time you would have seen much more detail in this situation. You would be able to tell me that on John’s (the guy with the video camera) jacket there is a blue logo. Those of you with really good vision would even be able to read that its a logo for Bell.
Fovea; the eye’s ‘telephoto’
The amazing part about human vision that makes this possible is the fovea. A small part of of the retina which has a very high density of ‘cones’, light sensing cells which are specialized for colour recognition. If John was standing in area of your peripheral vision you would have a much more difficult time seeing the Bell logo. If you would be able to see it at all, at the same distance. Throughout all of the eye there is a distribution of rods, they are more specialized for low light situations. There are less rods around the edge of your vision and more towards the center.
Since our vision is gifted with the amazing resolution packed into the fovea’s cones we are able to see details on far away objects as if we were looking with a longer focal length lens. Like this shot;
If you set out to take pictures which capture what you are seeing its not likely you will be successful, you’ll always be losing the width, or foveal details of subjects.
Think to displaying the image; the viewer’s FOV is likely to be full of distractions and visual elements beyond your control. Look at the image above, I can’t control the coffee mug, pencils pens, speakers and everything else on your computer desk, which is in your FOV right now. All I have is the visual space on your screen which I get to play with. Inside that little box I’ve simplified and removed visual elements, organized and structured the frame in a way that is more likely to keep your eye inside it, rather than skipped over or through.
A photographer skilled in organizing visual space and composition makes successful photographs because he is using his eyes and visualization skills to present a beautiful organized image to your eyes. The camera is only a tool to facilitate that vision.
If you are shooting for a gallery, or other large presentation, you can shoot for more detail as the presentation will allow much more compositional complexity. The final image is going to be filling more of the end viewer’s FOV, and have less distractions around it. -Think Edward Burtynsky and his massive prints from large format film-
-Click for the Introduction to, and Directory for; Foveas and Photographs series
