Types of Lenses and Their Uses
Lens types described here primarily refer to lenses for Single Lens Reflex (SLR) Cameras. This type of camera utilizes interchangeable lenses. SLR cameras also enable image composing, exposure measurement and focusing through the same lens that will be taking the actual photograph.
SLR cameras make the use of Macro, Telephoto, Wide Angle and Zoom lenses much more feasible. They take out much of the guesswork and increase opportunities for you to achieve your creative and journalistic goals.
There are SLR lenses available for almost any photographic need you can imagine. The types listed below represent the most common and widely available. SLR cameras are sold as the camera body only, the camera with a normal lens or the camera with a zoom lens whose range usually includes the range of a normal lens. These are the most common starting configurations.
An SLR lens is not one lens. The actual lens barrel contains 5 or 6 or more “elements” which are organized into “groups”. Each element would qualify as a lens. So the SLR lens is actually a system of lenses that produce high quality images.
The normal lens is often the one that comes with your camera when it is new. For SLR photography a normal lens will commonly be in the range of 50mm to 55mm. In all cases the normal lens is intended to be one that gives your pictures the perspective that you see with your unaided eyes.
Wide Angle Lenses
These will have a focal length less than that of the normal lens. Wide angles lenses will give you a perspective as if you backed up some distance to get more of the scene into your picture. They begin below 45mm. You will find that a 35mm lens gives a sufficiently wide perspective for most shots. A 28 mm, although popular, is past the threshold of noticeable distortion and is too drastic for some purposes.
More on Wide Angle Lenses
When photographing groups of people with a wide angle you will be making people at the edges look wider (and heavier) that they actually are. That’s why you probably don’t want to use a wider angle lens than you need to fit everyone into the picture. Experiment with cloud effects in a wide angle lens. You’ll enjoy the dramatic results.
These lenses will give an effect as if you walked up to a section of the scene you are shooting. However, the effect on your image is not the same. Background objects such as clouds, hills, or buildings will appear disproportionately large in relation to a subject that is in the foreground. The effect is unmistakable. The intentional use of this effect can produce dramatic results such as when you put a rising sun prominently into the background. Protect your eyes at all times. Be careful not to damage to your camera and never shoot the sun unless it is at the horizon.
For consumer SLR photography telephoto lenses begin at 85mm and go up to 2000mm or more. Again, considering the format, a 50mm lens will magnify about 1:1 (No magnification) and a 200mm will magnify about 4X (Four times the 50mm normal lens perspective.). So it seems you can divide by 50 to get the “X” approximate magnification value of a telephoto lens.
More on Telephoto Lenses
a. A telephoto at about 100mm will yield superior portrait photos.
b. “Long” telephoto lenses, say 200mm and over, will yield best results when you are able to use a tripod to reduce vibration. Any telephoto lens magnifies shaking or other movement of the camera.
c. A telephoto lens will magnify haze in the atmosphere. In many situations outdoors a telephoto will do best with a haze reduction filter added.
This is the lens that produces those great close ups of flower blooms and bugs. With a macro you can place the front element of your camera lens just a few millimeters from the subject. The effect opens whole new worlds for photography.
More on Macro Lenses
a. You can purchase a normal or zoom lens that has macro functionality.
b. The biggest issue with this type of lens is “depth of focus”. Focus on a point of interest and notice that other points merely millimeters away are already thrown out of focus. If you are photographing a butterfly with a macro you will have an impossible task trying to have the entire bug in focus.
c. To succeed with a macro lens you’ll need a lot of light or fill flash or you’ll have to back off a bit.
d. Both natural and flash lighting are issues with a macro. Successfully using a flash with a macro is a real talent.
The zoom lens is a way to get multiple lens types in one unit. A particular zoom can operate within the wide angle range (Such as 17 – 40mm). Another zoom might operate through the normal lens range and up to 200mm. There are zooms can that operate within the long telephoto range (100 – 400mm for example). Zooms can also include macro functionality.
If you are off on an expensive and far away vacation and can only take one lens consider taking a zoom that includes near normal in its range and up to about 200mm. Be sure that your zoom lens transitions smoothly through its range and that it doesn’t require you to take your attention away from the view finder.
More on Zoom Lenses
a. An affordable zoom lens will be considered to be a “slow” lens (f/3.5 or higher is common). They often require higher lighting levels.
b. A zoom lens has a higher element count and more mechanical functions than other lens types. Therefore, quality workmanship is required to achieve good results. That usually means higher cost.
Optical Zoom vs. Digital Zoom
There are two types of zoom function available on most cameras sold today:
Optical Zoom – refers to increasing the zoom lens power through settings on the lens which change the physical optical system in a way to make a portion of the scene look closer through optical magnification in the classic dictionary sense.
Digital zoom – Some claim that digital zoom is nothing more than a marketing ploy. Digital zoom is achieved through software within the camera that enlarges a portion of the original image in a way similar to the way photo editing software can enlarge a picture. Digital zoom may have its uses but optical zoom is true zoom and not merely software manipulation that results in less original image information.