Lens

Lets talk about a lens today... 

ok... wiki defines lens as.....

A photographic lens (also known as objective lens or photographic objective) is an optical lens or assembly of lenses used in conjunction with a camera body and mechanism to make images of objects either on photographic film or on other media capable of storing an image chemically or electronically. While in principle a simple convex lens will suffice, in practice a compound lens made up of a number of optical lens elements is required to correct (as much as possible) the many optical aberrations that arise. Some aberrations will be present in any lens system. It is the job of the lens designer to balance these out and produce a design that is suitable for photographic use and possibly mass production.

There is no major difference in principle between a lens used for a camera, a telescope, a microscope, or other apparatus, but the detailed design and construction are different.

A lens may be permanently fixed to a camera, or it may be interchangeable with lenses of different focal lengths, apertures, and other properties.

ok in other words lens is a very important item in a camera. Without lens, light cant come in into the cam... Without light u can see anything. Zzzz your talking about taking photographs without light? 0.0 what a joke!

Anyways, you all know that lens cost is sometimes higher than the body.. lol! and yeah, through my personal experience, u can differ a 18-55 mm lens and a 18-200 mm lens. a 18-200 mm lens cost over 1.5k (at least) and a 18-55 mm lens u can get it for free if u buy a DSLR. lol..

you may say that its only the zooming that is expensive for 18-200 mm but not only that, the depth of view is much much more nicer than the 18- 55 mm coz your lens is longer. 

So, why do professional photographers buy 10k over lens? Haha cause they are good! lame le....