The widest possible aperture on a camera or lens. The wider it is, the faster a camera is said to be.
Refers the a lensâ€(tm)s ability to transmit light. Fast lenses transmit more light than slow lenses. Lens speed is calibrated in f-stops. Lower numbers (f/1.8, f/2.0) indicate faster lenses. Speed is a desirable quality because it allows the photographer to shoot in relatively low light
The largest lens opening, e.g. f2 not f16. A fast lens transmits more light and has a larger opening than a slow lens. (see f-stop & Slow lens)
In theory, a fast lens has a larger opening and transmits more light than a slow lens. Lens speed is determined by the maximum aperture of the lens (the largest lens opening or the smallest f-number) in relation to it's focal length. The "speed" of a lens is relative, a 400 mm lens with a maximum aperture of f/3.5 is considered extremely fast, while a 28mm f/3.5 lens is thought to be relatively slow.
Lens Speed: Refers to the ability of a lens to pass light. It is expressed as a ratio: the focal length of the lens divided by the effective diameter. A fast lens which passes more light receives a lower rating such as f/3.5. The f/number = focal length/aperture.
Also known as the f-number, it is the ratio of the focal length of the lens to its clear aperture.
The largest lens opening (smallest f-number) at which a lens can be set. A fast lens transmits more light and has a larger opening than a slow lens. Determined by the maximum aperture of the lens in relation to its focal length; the "speed" of a lens is relative: a 400 mm lens with a maximum aperture of f/3.5 is considered extremely fast, while a 28mm f/3.5 lens is thought to be relatively slow.
The largest aperture(smallest F-stop) at which a lens can be set. Fast lenses transmit more light and have larger openings than slow lenses. Determined by the maximum aperture in relation to focal length. Lens speed is relative: a 400 mm lens with a maximum aperture of F/3.5 is considered extremely fast, while a 28mm F/3.5 lens is considered to be quite slow.
The widest aperture at which a lens can be set. A lens with a fast speed has a very wide maximum aperture, such as Æ’/1.4, for example, and transmits more light than a lens with a slow lens speed, such as Æ’/8.
Refers to the lens aperture or its ability to transmit light. This is measured in F-stops.
Refers to the ability of a lens to transmit light, represented as the ratio of the focal length to the diameter of the lens. A fast lens would be rated f/1.4; a much slower lens might be designated as f/8. The larger the f number, the slower the lens.
Optical speed, expressed by f-number. Smaller f-number means faster lens.
Refers to the maximum aperture of a lens. One with a wide aperture is called "fast". e.g. a f/1.4 lens, transmitting more light than a "slow" lens, e.g. a f/5.6 lens. (Visible) Light Radiated energy which forms that portion of the spectrum visible to the human eye, from 400 nanometers in the ultraviolet frontier to 700 in the infra-red boundary.
Lens speed is a qualitative concept related to the relative aperture diameter, or f-number of a photographic lens. The "speed" of a given lens refers to its maximum aperture.