The Lens & Focal Length

The distance from the lens to the focal plane when the lens is focused on infinity is called focal length.

The longer the focal length, the greater the magnification of the image, the less depth of field and the narrower angle of view.
For a 35mm film camera a 50mm lens is considered "normal". This means it gives an angle of view about the same as how we see with our eyes.


1. Set the "camera" to 50mm and click the shutter release. This is the same focal length as the Original Exposure on the left.

2. Next, set the "camera" to any other focal length and notice the affect this change has the magnification of the image and the angle of view.

CAMERA:    Lens Focal Length:      

Original Exposure:

New Exposure:

All Photographs ©2011 Luis Marin