Photographic Image Quality:
Lens Characteristics (2): Field of View
All of these images were taken with the Olympus E-M1, micro-4/3 sensor, from exactly the same position next to the entrance of Mission San Juan Capistrano. Both the actual focal length and its full-frame equivalent are listed; each shot is made with a prime (single focal length) lens (except for the 150mm, which is a zoom at its longest setting). Aperture was constant (priority) at f/11; auto-focus was set as near as possible to the statue; auto ISO and shutter speed varied according to the image contents.
▸ The field of view that you see here will vary slightly with sensor format. These have a width-to-height aspect ratio of 4:3; a full-frame or APS-C sensor has an aspect ratio of 3:2.
9mm "fisheye" (FF=18mm). The fisheye lens is unique both by covering an ultra-wide angle (approximately 180°) and by distorting the image circularly as its name suggests.
12mm (FF=24mm). This is probably the most popular wide angle length, both in prime lenses and as the shortest setting of many zooms. (This example is not how you'd actually use it to compose an image.)
25mm (FF=50mm). Considered "normal" since this is a close approximation of the human field of vision. For many years this was the lens for most 35mm film photography.
45mm (FF=90mm). Actually a short telephoto, this length has always been popular as a portrait lens, allowing a working distance that avoids distorting the subject's facial features.
150mm (FF=300mm). Zoom lenses in the FF 80–200 range are popular for many camera systems; this one goes a bit longer.
300mm (FF=600mm). You'll see the big white FF $$K version of this lens on the sidelines of many sporting events.