Aperture (Aperture) ------ elementary learning of

aperture (Aperture), Aperture is accustom to control the lens aperture above the camera the size of the components,GHD Midnight Gift Set 2011, is a few slices of very svelte metal movies formed through the middle of the light . Through the aperture to control depth of field size, lens quality, and work with the curtain to control the value of light. The larger the aperture prologue, the amount of light entering via the lens the more. We normally use the aperture size of the expression of F amounts. For example, f / 1, f / 2, f/2.8......f/22 to characterize. The higher the number, the smaller the aperture, and vice versa ambition be.

Aperture F = lens focal length / lens aperture diameter.

descending the criterion aperture is: F1, F1.4, F2, F2.8, F4, F5.6, F8, F11,GHD Straighteners NZ, F16, F22, F32,GHD IV Styling Set, F44 and F64. We can see from the upon formula, to fulfill the same aperture F value of long focal width lens of short focal length lens aperture diameter than the large.
Similarly, the smaller the aperture value under the same focal length lens the greater the efficient aperture in element time the more the amount of light, for example,GHD IV Salon Straighteners, from the F4 aperture .0 adjusted to F2.8, the amount of light more than doubled. Zoom lens for SLR cameras, the aperture F value is usually between F2-F22,GHD Red Butterfly 2011, and for consumption DC, the aperture F value is usually between F2-F11.

relying on the interior structure and different market location, a common lens aperture is divided into three categories: fixed aperture, Water Hou se aperture, cat's eye optical
ring and iris diaphragm.

nailed aperture: As the appoint suggests, the use of fixed iris lens,GHD IV Dark Straighteners, the lens aperture fixed there is merely 1 hole and can no modify the size of its aperture. This aperture is usually in the low-end devices such for compartment call camera, camera and optical rendition monitor and some other fewer demanding on the use of the product.

Water Hou se aperture: the first is a sequence of variable aperture holes of different sizes laid in a disk around the central axis; rotating circle panel can be migrated to the fitting size of the hole axis, and to control the aperture effect. Remember the mid-nineteenth century the invention of John Waters Hou se this aperture.

cat diaphragm: the aperture is also a common structure, named as its cat's eye shape. This aperture is one oval alternatively diamond-shaped center hole of the flat page into 2, and 2 half oval or half-diamond canvas metal hole formed on the row, relative activity of the cat diaphragm can be formed. Since cheap spend and size can be adjusted, so the cat diaphragm is widely used in entry-level expense of DC.

iris diaphragm: is composed of multiple overlapping bent aperture blades form, the aperture leaves tin be up to 18, and the greater the digit of leaves, aperture iris diaphragm the extra approximately circular. The clutch can change the blade circuitous aperture the size of the centre, and multi-blade design to invest light closer apt the circuitous aperture, so now the extensive majority of consumer-level digital camera and about entire of the SLR camera lenses have adopted this framework of the iris.

The following is the iris diaphragm
diagram:
the pore size of the lens can be watched in the picture 1 is a great aperture, picture 2 is a small aperture.


The following is the physical structure of the aperture
Figure: