Photography with Imre Z. Balint: Episode 1 – Aperture

Yeay! I finally finished my first webisode of a series I’ve always wanted to do about various topics in photography. The first subject I discuss is aperture, a very important aspect of taking great pictures. In my video I show what an iris diaphragm looks like, which is the mechanical part in a lens that controls the aperture that either restricts or permits additional light to penetrate the lens (thus light that hits the film or sensor).

In a (tiny) nutshell, here’s a summary of aperture:

• The aperture of a lens controls the amount of light that can pass through it to the film or sensor
• Larger aperture = more light passing through, smaller aperture = less light passing through
• This sounds odd, but: larger aperture = smaller f-number, smaller aperture = larger f-numbers (inverse relationship)
  
• Depth-of-field (DOF) is how much of an image is in focus
• Large apertures (smaller f-numbers) means smaller DOF; small apertures (larger f-numbers) means larger DOF
• Different lenses behave in different ways; wide angle lenses generally have large DOF even when small f-stops (aperture wider open) are used.

What can different aperture (or f-stop settings) be used for?

• When shooting portraits, it’s often more pleasant to blur the background with only the subject in focus, thus smaller f-numbers (wide open apertures) are used.
• When shooting subjects a short distance away (e.g. within 5 meters) with a telephoto (aka zoom) lens, DOF is usually quite small, however, at the same aperture setting when shooting a subject at a large distance (e.g. 20 meters or more), the DOF becomes larger. So DOF also depends on distance, not just the aperture setting.
• Most lenses have f-stop “sweet spots” where a particular or certain range of aperture results in a sharper photograph.

Some resources on aperture:

• http://en.wikipedia.org/wiki/Aperture
• http://en.wikipedia.org/wiki/F-number
• http://www.dpreview.com/learn/?/key=aperture
• http://www.photoxels.com/tutorial_aperture.html

To see my video in HD along with other clips, please visit my YouTube Channel; don’t forget to subscribe and rate 5 stars!