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Which digital camera lenses do you need?
One of the great things with DSLR cameras is the ability of changing the lens. This is probably also one of the important reasons you have decided to use a DSLR. By using your camera and learning more and more about photography you will soon wish for additional lenses. That is the fun and quite normal among DSLR users, even it can be expensive. I used the standard-zoom lens with the kit for quite a long time after I bought my first digital SLR a Nikon D70. Later I became interested in bird photography, and realized soon I needed a new tele lens. I ended buying a Sigma 50-500mm f4-6.3 zoom lens. This is an excellent lens, but now I am considering buying a faster zoom with a larger maximum aperture (smaller f-stop) allowing shooting in less light conditions. Which lens covers your needs? In any case when you are going to buy your next digital camera lens or the first for that sake, you need to specify your needs. Lenses cover different needs. Learn more about how to choose the right lens for your particular type of photography here Choosing the right lens is not easy as you will have to compromise between focal range, lens speed, size and weight, and of course (for most of us), the important factor price. Below you will learn more about the most important features of digital lenses and what you should look for before you decide. The two main groups – prime and zoom lenses A prime lens has fixed focal length, which means you cannot zoom the motive closer or more distant. Instead you – the photographer, have to move closer to or more distant from the motive to get the framing you want. Prime digital camera lenses are usually smaller, lighter, faster and cheaper than the zoom lenses. They are also regarded as having better optical quality because they are designed to cover only one focal length. A zoom lens can change the focal length and you can get the motive closer or more distant without the need to move yourself. Zoom lenses are heavier, bulkier, slower (needs more light) and more expensive compared to the primes. In general the zooms have lower optical quality due to the many glass elements inside. In digital SLR cameras the problem of getting dust on the sensor is an important issue. As such the zooms require less frequent lens changes something that will reduce the risk of getting dust on the sensor. The most important features of digital camera lenses Focal length
In DSLR cameras it is important to know about the crop factor. Since the sensor in the cameras is smaller than a 35 mm film frame you need to consider the crop factor. In cameras using the APS-C sensor this factor is 1.5x or 1.6x. This means a 50mm lens will have focal length in 35 mm terms equal to 75mm with a 1.5x APS-C sensor and 80 mm with a 1.6x APS-C sensor. If you are using a Four Third sensor camera the crop factor is 2x, meaning the 50 mm will have focal length of 100mm in 35 mm terms. Which focal length you should choose is depending on how you plan to use the lens. Maximum and minimum aperture Ideally you would by a lens with as large aperture (small f-number) as possible. These digital camera lenses allow you to shoot in low light conditions and when you need a fast shutter speed like in sport and action. Another important issue with the aperture is the ability to control the Depth of Field. The lager aperture the lens have the more expensive it is. So it will be a compromise between your needs/wishes and your budget.
Optical image stabilization Lenses with image stabilization have active elements that compensate for camera shake with long exposure times. These lenses typically allow you to use 3-4 times slower shutter speed and still be able to handheld the camera. This is very useful in low light conditions if you don’t want to use a tripod. On Nikon digital camera lenses image stabilization is referred to as "Vibration Reduction" (VR) while Canon uses "Image Stabilization" (IS). Lenses with image stabilization is typical more expensive compared to a similar lens without IS. Image stabilization is more important on lenses with long focal length as you also amplify the camera movements when zooming close. Focal length, maximum aperture, image stabilization as well as size, weight and price are the most important features with lenses. In addition there are a few lesser important (for most of us) features which you can read more about here A note on dedicated digital camera lenses for DSLR cameras Since the introduction of DSLR cameras, manufacturers have started to make lenses specifically for these cameras. Such lenses are designed to generate image circles to cover APS-C or "Four Thirds" sensors which both are smaller than 35mm film frames. This allows these lenses to be much smaller and cheaper to manufacture. This is of course good, but you should keep in mind if you plan to upgrade to a camera to a full frame sensor (sensors sized the same as a 35mm film frame), you cannot use these digital lenses. Nikon name these lenses EX while Canon uses EF-S. Which lens brand should you buy? Original or third party lenses What you should buy is dependent on your specifications and budget. Original lenses from the camera manufacturers tend to be more expensive, but not necessarily always of better quality. There are many good third party lenses that do very well in lens reviews. The only thing that is for sure is you need to buy a lens with the mount for your camera brand. Nikon, Canon, Sony, Pentax or Olympus lenses cannot be used between the different cameras. Even if you buy third party lenses from Sigma, Tamron or Tokina, you have to buy the lens with your specific camera mount. The most important part of a digital camera lens is of course the glass. The quality of the glass is what makes the lens. The best quality lenses with good optics are the most expensive. A lens can also have a less quality feeling if the housing is made primarily of plastic. On some lenses even the mount can be made of plastic. It is likely such lenses will not last as long as lenses with metal mount.
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