DSLR Lenses for Beginners

17 June 2011

Corinne Webb

Digital cameras have taken a huge leap forward over the past 18 months, with a range of new DSLR cameras on the market that blend the ease and functionality of a point-and-shoot digital job with the rich image quality of traditional SLR cameras. If you’ve seen or used one of these cameras, you’ll know that they take gorgeous pictures, but you probably don’t know anything about the real business end of the unit the lens. There are a variety of lenses you can use for different purposes and knowing which one to use and when, is what separates your average amateur wedding snapper and your average David Bailey. Below you’ll find an introduction to each type.

First of all, there’s some technical jargon you’ll need to get under your belt. The aperture is the opening that regulates the amount of light that passes through the lens. A very basic example of how the aperture is used would be that at night you need a larger opening (to allow more light into the camera) and during bright daylight, you need a smaller one (to prevent overexposure or saturation).

The focal length of a lens is a measure of how strongly it focuses (or converges) light onto the image sensor longer focal length tends to make distant objects appear larger, while a shorter focal length will magnify objects in the foreground. Think about when you look through the peephole on your front door the short focal length magnifies everything near the door.

Prime Lens Prime lenses come with a fixed focal length, and they are very simple because they have fewer moving parts than other types of lenses. The downside is that this means if you want to take pictures at 28mm, 100mm and 300mm, you’re going to need three separate lenses. However, prime lenses are small, light and relatively cheap and they produce excellent quality images. A great prime lens sells for a fraction of the price of a basic zoom lens. They generally come with a higher aperture, meaning they take good pictures even when light is a problem. For a portable DSLR camera, just choose the focal length you like most and get one nice prime lens.

Zoom Lens The focal length of a zoom lens can be varied without losing image focus, meaning that you can look at things from a wide angle (shortening the focal length) or you can zoom in to get a close-up on a particular subject (by increasing the focal length). Zoom lenses are often described in terms of the ratio of the minimum and maximum focal length if it ranges from 100mm to 400mm, the ratio would be 4:1 or “4x” zoom. Some lenses now get up to 10x or even 14x, but image quality for these shots simply can’t compete with prime lenses. The main advantage of zoom lenses is the flexibility it offers photographers they can take a variety of different pictures and compositions without having to move towards or away from their subject.

Macro Lenses These are used for extreme close-up photographs. They are generally used only by nature photographers or in forensic situations very small subjects that require lots of zoom and create a huge amount of detail. When you see a picture of a fly’s compound eye it was taken with a macro lens. They are generally very well-built and can be used to take normal pictures too, but most photographers would consider it a waste of money for a beginner to buy one of these.

Whatever type of lens you buy, be sure to take out specialist camera lens insurance for it these are expensive and fragile gadgets and you can never be too careful. Good luck, I hope you enjoy learning more about this wonderful hobby.