aperture ring, focusing ring

[jjbacoomba]

Hi yall. New to this forum and to photography. I want to know the difference between an aperture ring and a focusing ring. Feels like a dumb question but I have to ask anyway.

[ravncat]

Below is a nikon 50mm 1.4



The dial on the left - the front of the lens, is the focusing ring. The dial on the right most side at the back of the lens is the aperture ring.

The focusing ring controls where the lens focuses. (between closest and infinity)
The aperture ring controls the size of the aperture (in this case, between 1.4 and 16)

These days, modern lenses rarely have aperture rings, and many cameras require them to be locked in the position of the smallest aperture, (usually f22 or f16) so that the camera`s system can automatically control aperture.

[nickbedford]

The aperture ring on most modern lenses only displays the aperture. On older non-automated cameras, you would control the aperture directly via the aperture ring. Most lenses these days are controlled by a digital aperture setting on the camera.

Depending on the scale markings, it may look like this:

[ 22   16   8   5.6   4   2.8   2 ]

The higher the number, the smaller the aperture, as it is a ratio to the focal length. If the aperture is set to 5.6 for example, physical aperture size is 5.6 times smaller than the focal length, which may be 50mm or 35mm of 200mm or anything.

The focus ring on the other hand moves the focus elements back and forth to focus the image. It will also typically display the distance to the focus plane. On normal lenses this may look like:

[ 0.25   0.7   1   3   infinity ]

This would usually indicate meters on a normal lens (25cm is a typical minimum focus distance). Some lenses also display the feet measurements.