What does "f/2.8" or "f/4.5-5.6 II" mean?
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- Posts: 47
Tue Jun 01, 2004 12:28 pm
This is the 'result' of a ratio that indicates the aperture (lens opening). The closer the ratio (f/2.8 vs f/4, for example) the wider the opening. The wider the opening, the less depth of field - that is, a shallower 'zone' of the subject matter will be in focus.
Full stops measuer twice as much (or half as much light): 2, 2.8, 4, 5.6, 8, 11, 16, and 22 are full stops. Many of the best lenses can go one full stop wider at f/1.4, which pros like because of extremely shallow depth of field, like you might see in some food photography.
Wider apertures are indicative of higher-quality glass, and give the photographer a brighter viewfinder.
Aperture is always balanced against shutter speed. Thus f/2 at 1/500 sec gives you the same exposure as f/4 at 1/250 sec. In the latter example, the aperture is 1/2 of the first setting, but the shutter speed is is cut in half to compensate for the 'loss' of light coming through the now smaller aperture.
Full stops measuer twice as much (or half as much light): 2, 2.8, 4, 5.6, 8, 11, 16, and 22 are full stops. Many of the best lenses can go one full stop wider at f/1.4, which pros like because of extremely shallow depth of field, like you might see in some food photography.
Wider apertures are indicative of higher-quality glass, and give the photographer a brighter viewfinder.
Aperture is always balanced against shutter speed. Thus f/2 at 1/500 sec gives you the same exposure as f/4 at 1/250 sec. In the latter example, the aperture is 1/2 of the first setting, but the shutter speed is is cut in half to compensate for the 'loss' of light coming through the now smaller aperture.
2 posts • Page 1 of 1
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