"Normal" lenses

Just ran into a new term while lens shopping online.

Some seem to have this distinction in the description.

What is a "Normal" lens?

Thanks

Jim

A normal lens usually refers to a 50mm lens. Although more accurately it would be 50mm on a full frame and 30mm on a 1.6x body.

Here is a quote from wikipedia: "In photography and cinematography a normal lens is a lens that reproduces perspective that generally looks "natural" to a human observer under normal viewing conditions, as compared with lenses with longer or shorter focal lengths which produce an expanded or contracted field-of-view. Lenses of shorter focal length are called wide-angle lenses, while longer focal length lenses are often referred to as telephoto lenses."

Generally a "normal" lens has a focal length equal to the diagonal of the sensor/film.

afviper wrote in post #10954025
Here is a quote from wikipedia: "In photography and cinematography a normal lens is a lens that reproduces perspective that generally looks "natural" to a human observer under normal viewing conditions....

Whoever wrote that piece for Wikipedia doesn't understand that a lens' focal length has nothing to do with perspective.

Essentially, a "normal" lens has a field of view that emulates how you would see a scene viewed through a frame of the same size as a print of the image with the frame held at the same distance that you would view the print. As an example - if you have an 8x12 print of the scene and view it from 16 inches, you could hold up an empty 8x12 frame at 16 inches and view the same scene through it and see the same framing of the scene as the "normal" lens produced.

For more information on perspective and how to creatively control it, please read our "sticky" tutorial titled Perspective Control in Images - Focal Length or Distance?. The "sticky" thread can be found at the top of the General Photography Talk forum.

While Skip is correct that definition is difficult to visualize in reality...and in the end the result is that at NORMAL viewing distances (What is NORMAL?) the perspective within the FRAMED IMAGE (relationship of foreground to background) APPEARS to be PROPORTIONALLY the SAME as the scene when viewed without any lens/camera.

I've been thinking about this and wondering as Skip says, why people confuse perspective in photography...
It seems to relate as I suggeset, to viewing distances and What is normal?

If you view a subject, say a head shot/portrait from 12 inches and see the entire head and then shoot the IMAGE from 12 inches to fill the frame with the same view you saw with the naked eye (trying to see the entire face, not an easy task at 12"), you would have to use a wide angle lens and then the two perspectives would be identical (as Skip said)...the problem is compounded in that most of us don't see the perspective of reality (what's behind the face 12 inches in front of us when looking at it close up)...we only look at what's directly in front of our nose...if we did look beyond our nose, or the nose of the face 12" in front of us the perspective (size of background to foreground) would be the same as shooting with the wide angle lens...

...the answer to the confusion may be simply that our eyes can't easily make out that image (we see in stereo and convert into mono, like looking through binoculars) whereas the camera lens (in mono) can...I don't know....just thinking....

Thanks Guys-

It all makes sense but flew right by me at first.

Jim

SkipD wrote in post #10955264
Whoever wrote that piece for Wikipedia doesn't understand that a lens' focal length has nothing to do with perspective.

Hey - that's the beauty of Wikipedia! If you don't like it, change it!