Let us first understand the what is the effect of aperture in Digital Photography.
What Is... Aperture?
When you look at the technical specifications of a digital camera, one of the very first specification mentioned is its maximum aperture and/or its aperture range.
What is 'aperture,' what is a good aperture range, and how is aperture relevant when it comes to choosing a digital camera?
What Is Aperture?
Aperture is expressed as F-stop, e.g. F2.8 or f/2.8. The smaller the F-stop number (or f/value), the larger the lens opening (aperture).
[Note: Many camera user manuals today will refer to the aperture in terms of "aperture value" instead of f/value. I'm not sure when this trend started but don't get confused between "aperture" and "aperture value." Aperture value" is simply another way of saying f/value.]
In practice, unless you are dealing with a fixed-aperture lens (many simple point-and-shoot cameras have only one fixed aperture), the aperture of a lens is usually expressed as a range of fstops.
When you read the specifications of a camera, the aperture may be expressed in a number of different ways, the following three being the most common:
- Maximum Aperture:
 Max. Aperture | F2.8 |
This simply states that the maximum aperture for the lens is F2.8.
- Aperture Range:
| Aperture Range | F2.8-F8.0 |
This states the max. and min. aperture, the assumption being that there are standard increments between them.
- Maximum Wide-Angle and Telephoto Apertures:
| Aperture | F2.8-3.5 or F2.8(W)-F3.5(T) |
This gives the max. aperture for the wide-angle (F2.8) and telephoto (F3.5) focal lengths of a zoom lens.
It is usually not too difficult to figure out that a stated range deals with maximum apertures and not max and min apertures: the mimimum aperture should be quite small at F8, F11, F16 or F22.
A "fast" lens is one that has a large maximum aperture (F2.4, F2.0 for current digital cameras; F1.4, F1.2 for 35mm film cameras.
Posts
No comments:
Post a Comment