Remember the play with Aperture that I did with the AV-1 a few posts back, since I have no idea how that would turn out, I took heed from Bai and read up on Aperture (after being a b1@tch)…based from a certain lens I wanted…
Excerpt from here.
In optics, an aperture is a hole or an opening through which light is admitted. More specifically, the aperture of an optical system is the opening that determines the cone angle of a bundle of rays that come to a focus in the image plane.
It sounds nifty, and that is the concept I really know of (think iris) but I went to focus on the photography part more (where numbers are present), and I screwed the formulas all together for later maybe if I become that g33ky enough…
I really wanted to take notes. But wiki explained it so well that I would just paste the whole shebang here and read it over and over again.
In photography
The aperture stop of a photographic lens can be adjusted to control the amount of light reaching the film or image sensor. In combination with variation of shutter speed, the aperture size will regulate the film’s degree of exposure to light. Typically, a fast shutter speed will require a larger aperture to ensure sufficient light exposure, and a slow shutter speed will require a smaller aperture to avoid excessive exposure.
A device called a diaphragm usually serves as the aperture stop, and controls the aperture. The diaphragm functions much like the iris of the eye—it controls the effective diameter of the lens opening. Reducing the aperture size increases the depth of field, which describes the extent to which subject matter lying closer than or farther from the actual plane of focus appears to be in focus. In general, the smaller the aperture (the larger the number), the greater the distance from the plane of focus the subject matter may be while still appearing in focus.
The lens aperture is usually specified as an f-number, the ratio of focal length to effective aperture diameter. A lens typically has a set of marked “f-stops” that the f-number can be set to. A lower f-number denotes a greater aperture opening which allows more light to reach the film or image sensor.
Aperture priority refers to a shooting mode used in semi-automatic cameras. It allows the photographer to choose an aperture setting and allow the camera to decide the shutter speed and sometimes ISO sensitivity for the correct exposure. This is sometimes referred to as Aperture Priority Auto Exposure, A mode, Av mode, or semi-auto mode.[3]
Maximum and minimum apertures
The specifications for a given lens typically include the minimum and maximum apertures. These refer to the maximum and minimum f-numbers the lens can be set at to achieve, respectively. For example, two versions of the Canon EF 70-200mm lens have a maximum aperture of f/2.8 and a minimum aperture of f/32.
The maximum aperture (minimum f-number) tends to be of most interest; it is known as the lens speed and is always included when describing a lens (e.g., 100-400mm f/5.6, or 70-200mm f/2.8).
A typical lens will have an f-number range from f/16 (small aperture) to f/2 (large aperture) (these values vary). Professional lenses for 35mm cameras can have f-numbers as low as f/1.0, while professional lenses for some movie cameras can have f-numbers as low as f/0.75 (very large relative aperture). These are known as “fast” lenses because they allow much more light to reach the film and therefore reduce the required exposure time. Stanley Kubrick‘s film Barry Lyndon is notable for having scenes shot with the largest relative aperture in film history: f/0.7.
Lenses which have a fixed focal length (FFL) and large aperture are favored especially by photojournalists who often work in dim light, have no opportunity to introduce supplementary lighting, and need to capture fast breaking events.
Zoom lenses typically have a maximum aperture (minimum f-number) of f/2.8 to f/6.3 through their range. A very fast zoom lens will be constant f/2.8 or f/2, which means the relative aperture will stay the same throughout the zoom range. A more typical consumer zoom will have a variable relative aperture, since it is harder and more expensive to keep the effective aperture proportional to focal length at long focal lengths; f/3.5 to f/5.6 is an example of a common variable aperture range in a consumer zoom lens.
Aperture area
The amount of light captured by a lens is proportional to the area of the aperture, equal to:
Where f is focal length and N is the f-number.
The focal length value is not required when comparing two lenses of the same focal length; a value of 1 can be used instead, and the other factors can be dropped as well, leaving area proportion to the reciprocal square of the f-number N.
If two cameras of different format sizes and focal lengths have the same angle of view, and the same aperture area, they gather the same amount of light from the scene. The relative focal-plane illuminance, however, depends only on the f-number N, independent of the focal length, so is less in the camera with the larger format, longer focal length, and higher f-number.
My nose kept dripping of blood. I have just sported an instant nosebleed
I’m still trying to compare differences which regards to aperture, No apparent proof as of yet. Renault only goes at an aperture of 2.8 and nothing more. While the av-1 can go as high as a 1.8. I have finished the centuria 200 roll on vivi, and I have loaded a new centuria on the av-1. I have to make notes for that since I have hastily clicked away on some scenes the seems to be worthy of the taking. lol@impatience.
and Just so this isn’t a non-picture post.
aperture : F/8 (wtf?)
