Understanding Camera Lenses

The world of lenses can be astoundingly confusing when considering terms such as Prime, Telephoto or Zoom, Focal Length: short or long, Depth of Field, Wide Angle, Telephoto, Image Stabilization, Aperture, F-Number, Shutter Speed, and so on.

After considering writing an article explaining all of this I ran across one by Cambridge Color which is simply unbeatable. If you have the time to absorb this it will refresh your understanding or give you data you have long been wishing you had.

An example of the information within this article which is valuable is the following tutorial on how to estimate how exposure time is relative focal length.

"A common rule of thumb for estimating how fast the exposure needs to be for a given focal length is the one over focal length rule. This states that for a 35 mm camera, the exposure time needs to be at least as fast as one over the focal length in seconds. In other words, when using a 200 mm focal length on a 35 mm camera, the exposure time needs to be at least 1/200 seconds-- otherwise blurring may be hard to avoid. Keep in mind that this rule is just for rough guidance; some may be able to hand hold a shot for much longer or shorter times than this rule estimates. For users of digital cameras with cropped sensors, one needs to convert into a 35 mm equivalent focal length".

The site has an About page as a start
And if you have further questions Sean invites you to join their new Digital Forum here

Enjoy the read and the site. It is a wealth of information and resources.