Optimum Aperture - Format size and diffraction
From time to time you see statements posted on web forums complaining about the performance of lenses on DSLRs when they are stopped down to f22 or smaller apertures.
For each lens there is an optimum aperture at which the lens produces the best image definition. For copy work, this optimum aperture should be used whenever possible.
5 was the optimum aperture (as it was also for the SX10 IS), and as you shoot at apertures above 5.6 diffraction effects started to reduce resolution.
Depth mode
Program mode on some Canon cameras that sets the optimum aperture to ensure enough depth-of-field to make the whole of the subject sharp.
Search SWPP and BPPA
Information provided by: SWPP BPPA
More Photographic Terms ...
(A) Exposure mode where the camera determines the optimum aperture for you.
Aperture
The variable diameter hole used to control the amount of light passing through a lens.
In a nutshell, this mode tries to calculate the nearest and farthest elements in a scene and then calculates the optimum aperture and point of focus to use to get them both in sharp focus in your picture.
In a camera that has a 35mm focal length and width of 35mm, the optimum aperture size is 1 because the ratio of 35 to 35 is 1. That probably all sounds confusing, because it is.
 See also: Aperture, Image, Sharp, Light, Lens
|
