By Fredrik Silverglimth

In Photography, your lens is often your most important purchase. This photography tutorial outlines some important qualities of different lenses, and how each performs in identical situations.

Choosing a lens is often more difficult then choosing a camera when it comes to purchasing. One thing to remember is that a lens will last several times longer than digital cameras. A D-SLR has a limited lifespan of a couple of years, the prices on cameras just keeps on dropping and purchasing a new camera every 3-5 years is quite reasonable if you want good quality photographs & equipment. A lens on the other hand will (if handled correctly) last much longer then that, so a good lens will be an investment that you can use for a longer period of time.

Another thing to think about is the fact that all the light that reaches the sensor needs to pass through the lens. A low quality lens on a high quality camera will result in bad image quality, but a good lens on a low quality camera can still produce good results (and with low quality camera I mean the companies “entry level” D-SLR cameras).

It’s important to realize that different lenses distort and compress the view. A wide angle lens will distort the view and distances can seem greater than they really are, while in contrast, a telephoto lens willcompress the view and make far away object seem closer than they are. To show this effect I have taken three photos with different lenses, the front object (a street sign) is kept at the same size but the background is drastically different.

Above: 18mm, Wide Angle
Above: 50mm, Normal
Above: 300mm, Telephoto

Normal lens

Normal lenses have a focal length of around 50mm; it resembles the view of the human eye and creates a natural view — unlike wide-angle that distort and telephoto that compresses the view. These lenses usually have a very low f-number, which makes them perfect for photographing in low light conditions.

Back in the days this was the standard lens everybody had, often a 50mm prime lens (more about prime lenses later in this article) with an aperture of f/1.2–f/1.8. The fact that they were so widely used might be one of the reasons why they have now been left behind for most beginners and amateurs — they are just seen as too boring.

Wide-angle lens

Lenses with a wide angle of view have become standard as kit-lenses on most low-end D-SLR cameras on the market, always as zoom lenses. These lenses are great for landscapes, architecture and indoor photography — but be aware of the distortion they create. The closer you are to your object the more distorted it will become, and the distortion is most predominant in the corners.
With such short focal length they can be useful in low-light situations, both because they take in light from a wider angle and because a little camera shake is not as visible as it is on longer focal lengths.

Telephoto lens

These lenses have a narrow view field and a long focal length. Telephoto lenses are great for wildlife and sport photography, and can be good to use for portrait when you want to isolate the model from the background. Telephoto lenses compresses the view which can be both positive and negative depending on the situation.

Telephoto lenses with their longer focal length require better light conditions or the use of a tripod. There are fast telephoto lenses, like a 400mm f/2.8, but these are often very expensive and out of reach when it comes to most amateurs — and most of these lenses are too heavy to be handheld.

The last decade most companies have started to produce these high end telephoto lenses with Image Stabilizer (different companies have different names for it, but the effect is the same) to make them more usable without tripods. Lately this feature has been implanted in more and more low-end lenses as well.

Macro lens

Macro photography is close-up photography. Macro is a word that has been severely abused lately, every photograph of an insect or flower is not macro, and many people seems to have missed the point of what macro is supposed to be. True macro photography is at the scale of 1:1 or greater — this means that the object you’re photographing should be the same size or larger on the sensor.
Most macro lenses have a focal length between 50mm and 200mm, and they usually have a large maximum aperture (low f-number) that gives them both the ability to be fast as well as totally isolate the subject. The background and shallow depth-of-field is a very important part of macro photography and can take quite a lot of time to master.

Technorati Tags: basics, lens, macro, Photography: The Basics, telephoto, Tips, wide angle