Digital SLR Cameras

Many first-time digital SLR camera buyers exhaust their entire budget in buying the camera. That's not a bad thing except for the fact that DSLR cameras come fitted with a 'kit lens', which is usually a cheap one that lets you start shooting right away. Good lenses, however, let you tap the full potential of your DSLR. But buying them could be tricky, what with the abundance of jargon in this field. Also, the kind of lens to be purchased depends on the whether the photographer is a professional or an amateur. Finally, as good lenses can cost you serious money, getting enough bang for your buck is important.

MAJOR LENS A MAKERS

Canon, Nikon, Olympus, Pentax and Sony make lenses that are compatible ` with their own cameras. Third-party lens manufacturers such as Tamron, Tokina and Sigma make lenses that work with multiple models.

Invest in lenses to realise the infinite potential of your digital SLR camera

THINGS TO LOOK AT

Focal Length (F L) Measured in mm, this is the distance between the lens and the point where the light rays are focused. More simply, it is a measure of how much will fit into your picture. FL determines the right lens that you need to choose for shooting a certain subject. An FL of 50 mm corresponds to our normal vision.

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GET THE RIGHT LENS

MACRO: Higher focal length for moving subjects, lower for still ones. Magnification ratio of at least 1:1

TRAVEL: Lightweight lenses. Telephoto zoom lenses are a good option

WILDLIFE: Focal length depends on how far the subject would be. Telephoto prime and zoom lenses are a good option

LANDSCAPE: Wide-angle digital-only lenses; 10-24 mm, even 28 mm 

PORTRAIT:50-100 mm after the crop factor is factored in. Large max aperture

Focal Length Multiplier (FLM) Digital cameras mostly have sensors that are smaller (APS-C format of 24 mm x 16 mm) than a full-frame sensor (36 mm x 24 mm). These produce a cropped image and, so, the lens' FL has to be multiplied by FLM (usually 1.3-2) to get the effective FL. For example, with an FLM of 1.6, an 85-mm lens will have an effective FL of 136mm (85 mm x 1.6). Lenses designed for full-frame cameras work fine with APS-C cameras, but the reverse doesn’t hold true.

WIDE-ANGLE LENS The FL of a wide-angle lens varies from 12 mm to 35 mm. Such lenses can squeeze in a lot more of the scene into the frame without you needing to step back. However, shooting with these lenses can give the image a slight distortion at the edges. Ultra-wide angle or fish-eye lenses can be used to take 180-degree pictures.

TELEPHOTO LENS   Telephoto lenses have FLs usually upwards of 85 mm. A lens with a longer FL does the opposite of a wide-angle lens; it focuses on a small part of the scene and expands it to fill up the 5 frames, isolating it from the back-ground. These lenses are perfect for shooting portraits and wildlife, where you can't go too close.

MACRO LENS: These are used for close-ups of very small subjects, such as insects. Normally, they have a magnification ratio of 1:1 or greater and an FL of 50-200 mm. These lenses allow you to focus on close objects.

ZOOM LENS These allow the photographer to vary the lens' FL within a certain range, unlike 'prime' lenses that have a fixed FL. Common FL ranges for zoom lenses are 18-55 mm, 70-300 mm, and so on. However, zoom lenses might result in a slightly poorer picture quality than primes and are much bulkier and slower.

APERTURE: Expressed in numbers such as f/2.8 (1:2.8) or f/4 (1:4), it refers to the circular opening in the lens that lets light in. Here, a smaller number means a bigger opening (which allows more light to enter), and vice-versa. So, a lens with a bigger aperture is suitable for shooting under low light conditions without the use 1 of flash. A bigger aperture also helps you blur the background at longer FLs.

IMAGE STABILISATION: it ensures that there is no 'shake’ in the picture and you get sharp images even at slow shutter speeds. lf your camera doesn't have this feature inbuilt—Pentax, Olympus and some Sony models incorporate it in their body—consider buying telephoto lenses that have it. Different manufacturers have different names for this feature. Here is a guide; Canon - lmage Stabilization (IS); Nikon — Vibration Reduction (VR); Sony (Nex system) — Optical Steady Shot (OSS); Sigma — Optical Stabilization (OS); and Tamron — Vibration Control (VC).

LENS COMPATIBILITY: if you own a DSLR camera, buying a lens by the camera manufacturer will usually ensure that your lens is compatible. However, for the autofocus function (AF) to work, there has to be an AF motor either inside the camera (some Nikon cameras have a screw driver in the body that adjusts the lens) or built inside the lens (AF-S lenses). For Nikon cameras without an AF motor, such as D31OO and D5100, you would require an AF-S lens for the AF function. When buying third-party lenses, ensure that the lens is compatible with your camera. This is mentioned along with product details on the manufacturer's website.

VALUE FOR YOUR MONEY: For the price-conscious, third-party lenses offer good value. However, most third-party options are meant for Nikon, Canon and Sony cameras. While some may argue that third-party lenses are not as good as those made by camera makers, it makes sense for amateurs to buy them if the price difference is substantial. However, remember that third-party lenses have a lower resale value.