Understand your DSLR: what to look out for and what it all means

Here is our guide to what you need to look out for when buying a DSLR, and what it all means.

Lens mount

The lens mount on your DSLR will determine what lenses you can use. It's an important decision because once you've invested in several lenses it's hard to get out of that camera system without selling everything and starting again. One way of saving money is to buy lenses from an independent lens company such as Sigma, Tamron and Tokina. These alternatives are usually cheaper than equivalent lenses from the main manufacturers.

Size

Depending on the camera you want to go for, always check it out in the shop before you commit to buying one. Cameras do vary in size and this can mean that the one you've had your eye on may be a bit too heavy and bulky for you. On the other hand, you may find that a smaller camera is a little fiddly. Camera shops are usually more than happy for you to get a feel for the camera prior to purchasing it.

Connection

Most DSLRs use a USB lead to connect them to your computer, which allow you to download your pictures or transmit tethered feeds to your computer's monitor. Direct from camera to computer, USB 2.0 Hi-Speed is the fastest option available for transmitting images, but external card readers are better as they will save your camera battery. You can also view images on a TV through the AV socket, while more recent models may also sport a HDMI socket.

Flash

Most of today's DSLRs have a built-in pop-up flash, which comes in very useful for both indoor portraits and ‘fill-in' flash outdoors. For those just starting out, the built-in flash will serve you well and is a great way to grasp the basics of flash photography. When you are ready to graduate to something bigger, an external flashgun is the next step.

Autofocus system

The autofocus systems on DSLRs are getting better and better. While most entry-and mid-level cameras boast (perfectly competent) systems with nine or 11 individual AF points, some  semi-pro models, such as the Nikon D300s, boast up to 51. Look out for AF systems with cross-type sensors, which are sensitive to both horizontal and vertical movements, as opposed to standard sensors that use either a horizontal or vertical plane only.

Controls

Camera controls vary from manufacturer to manufacturer, but by and large the primary controls are positioned in roughly the same place. It's all down to personal preference; would you like to change camera settings using buttons or dials, or by using the menu? Some cameras allow you to do both, while others may allow you to fully customise the interface to suit your needs.

Build quality & weatherproofing

While you should obviously aim to avoid dropping your new camera, a few knocks are unavoidable. While most DSLRs are encased in a tough plastic outer shell, more expensive ones may also sport an aluminium chassis for extra durability. Some models also offer weatherproof sealing.

Viewfinder

Thanks to the optical arrangement inside the top of your DSLR the viewfinder allows you to  see exactly what your camera sees - or nearly. Most entry and mid-level DSLRs don't provide the 100% coverage of top-end models, with figures closer to 98% or 95%. In practice this means that your camera will record a little bit more around the edges than you see through the viewfinder. Of course, you can always crop an image after it's been taken.

LCD screen

Most screens measure 3" from corner to corner, although some entry-level models sport 2.7" screens. A resolution of 230k-dots is standard for most entry and mid-level models, but some models offer a high-quality resolution of 920k-dots or more. Some DSLRs also have adjustable  CD screens which can be useful when shooting from awkward angles.

Technolgoy

See also our DSLR technology guide, to find out about features such as Live view, image stabilisation, dynamic range, ISO performance and movie mode.