Looking at a scene from one point of view at any given moment has limitations regarding how wide or how high one can see. This is referred to as peripheral vision. Our normal limits of peripheral vision are less than 180 degrees wide and 100 degrees high. Of course, we can visually apprehend a much wider scene by scanning it. That is by looking all around and mentally piecing the scene together.
In photography, a fish eye lens also known as a wide-angle lens shows in a single image a wider view than is normally allowed by our peripheral vision. To accomplish this wider view, straight objects can appear to bend especially near the edge of these kinds of photographic images.
The wider the lens the more space appears to curve in the photograph. Below is an example of a wide-angle (fish eye) image.
Notice that the fish eye lens shows an expansive image that includes in a single view left right up and down.
Since we don't see with the wide angle, fish eye lens, we are rarely aware of the curving effect as we scan a scene to apprehend it.Below is a series of five photographs each taken in the normal peripheral field of vision.
Beginning with photograph number one which is pointing upward to the top of trees the photos continue in sequence forward until the fifth photograph which is pointed directly downward to a stream below a bridge. The series of photographs below represent a series of views that would be typically experienced as one scans a scene.
The two photographs below are composites of the five photographs above. In essence, these last two photographs show an expansive 'fish eye' view, which was created by me in Photoshop as a way to show a seamless composite, which is closer to our actual experience of scanning a scene. In each of the photographs above we did not really notice curved space.
However in the composite photograph below we can notice the curving effect as if space itself is bulging and tapering as multiple points of views seamlessly merge. In the second below photograph below sections are numbered to indicate the above photographs and the white lines are superimposed to indicate the curving of the space.
The technical term used by artists to describe this effect is called curvilinear perspective. The visual logic of curvilinear perspective, which allows the expansive views in my paintings, also produces a curved look.