Lenses are marked with a series of numbers along the aperture dial, the number refer to the F-Stop. The numbers indicate the amount of light to pass through the lens barrel to the sensor. Typically you would find the following f-stops: f2.8, f4, f8, f11 etc.
A telephoto lens is a lens that brings objects that are physically distant, closer to the camera sensor. A telephoto lens works much like a telescope or binoculars. A decent telephoto lens is practically a necessity for Wildlife photography. Typically anything above 50mm is considered a telephoto but most commonly lenses in the 100mm and 300mm range fit this description.
The super telephoto lens range typically is considered 400mm and above and most commonly used in professional sports and wildlife photography
A prime lens is any lens that only consists of a single focal length. 100mm, 300mm etc. Prime lenses used to be regarded as far sharper than a zoom lens Modern zooms however have closed the gap somewhat.
A zoom lens is any lens that ranges from one focal length to another. 28-70mm, 70-200mm etc. The modern professional zoom lenses usually deliver very high quality images.
Macro lenses enable one photograph small objects at a close range. Typically a macro lens will focus to 1:2 life size. This means the object will appear half the size it actually was when you complete your image. Most professional macro lenses will focus to 1:1, or full life size. Macro lenses are highly used in medical, botany and insect photography The most common macro range is 50mm to 105mm.
Wide angle lenses are most commonly used for landscape and architecture photography. Wide angle lenses allow for a wider field of view. Any focal length below 50mm used to be considered a wide angle however modern wide angle photography typically begins at 28mm and wider.
A fisheye lens is lens with an extremely wide angle of view, typically with large amounts of distortion. This is a specialized tool with limited use.
Sharpness refers to the resolving power of a lens, the amount of fine detail the lens is able to clearly expose. In nature photography sharpness is often considered the true measure of a lens.
A digital camera records an image electronically as opposed to film. To truly get the most out of a digital camera one should have a computer with a sharp monitor. Direct printing is an option but is impractical and defeats much of the purpose of a digital camera.
A sensor is the electronic devise that actually records the image, as opposed to film.
Charged coupled device, a type of sensor.
Complementary metal oxide semiconductor, another type of sensor. CMOS is often consider cheaper to produce and handles noise slightly better.
This refers to a digital sensor that is equal in size to a 35mm film plan.
This refers to the digital interface one will see in an image at maximum resolution. Similar to grain in film. The less noise in an image the higher quality the image will appear. Noise can be added as an effect as well. Higher ISO setting typically include more noise in an image.
This refers to the sensors sensitivity to light. A low number I. such as 50-100 ISO will produce a higher quality image. A faster iso setting such as 400-800 ISO will produce a faster shutter speed but at the cost of more noise in the image.
This literally refers to how fast the shutter actuates.
This is the piece of material that opens and closes to allow the light to reach the sensor. A fast shutter speed is best for sharp images but a slow shutter speed can emphasize speed or movement.
This typically is a setting that is manipulated per the type of lighting one is shooting in. Sun, cloudy, flash and florescent lighting are common white balance settings. Many professional digital cameras allow for fine tuning and custom white balance settings. The automatic white balance on new cameras is typically fairly accurate. Many photographers prefer the effects of a certain white balance setting regardless of the light they are shooting in.
Term used for on or off camera flash units.
This is artificial lighting. Usually built into a camera or attached via a hotshoe.
The electronic coupling on top of the camera connect flash or flash cords.
Lens terms and designations:
APO - Apochromatic, glass is typical, considered to be better displaying accurate colors. APO glass is also typically more expensive then standard glass lenses.
AF - Auto focus lenses are able to focus via an in camera drive or a separate lens drive.
MF - Manual focus lenses much be focused by hand, usual, by timing part of the lens barrel.
IF - Internal focus, this means the lens barrel will not rotate while focusing. IF is especially important when using filters such as a polarize.