Best focal length for your type of photography

Do you feel left out when other photographers start talking about lenses? In this quick guide we answer your burning questions about focal length and suggest the best focal lengths for what you want to shoot…

All images by Marcus Hawkins

Kit lenses have steadily improved, with many capable of producing sharp images and offering image stabilisation. But they’re limited in terms of their focal range, autofocus speed and maximum aperture. Investing in lenses that offer more extreme focal lengths or faster glass will give you more options.

Faster glass?

Fast lenses don’t necessarily focus faster, but they have wide maximum apertures. Wider apertures let more light in, so enable you to use faster shutter speeds to freeze movement. Today’s cameras perform well at high ISOs, but a wider aperture enables you to keep picture quality at premium levels.

Fast lenses provide a brighter viewfinder image, and the full performance of some autofocus points can only be achieved using the wide maximum apertures available on these lenses.

SEE MORE: What is focal length in photography?

What is a prime lens?

Unlike a zoom lens, which covers a range of focal lengths, a prime lens only gives you a single, fixed focal length to play with. That might sound limiting, but it forces you to move around a subject to find a better composition.

Prime lenses offer faster apertures than zooms, and tend to be better optically corrected – although the difference is negligible with top-end zooms – as well as being lighter to carry.

Some photographers prefer the signature look a fixed focal length can give their work, with 35mm, 50mm and 85mm primes being particularly popular.

SEE MORE: What your camera captures at every lens’ focal length

What lens would make a good upgrade from a kit lens?

If you want to explore landscape photography, a lens that offers an equivalent focal length in the region of 16-24mm should be on your list. If wildlife is more your thing, then a lens that has an equivalent focal length of 300mm or longer is pretty much essential.

A 50mm lens is a good general-purpose lens, perfect for everything from full-length portraits to documentary-style shots.

Avoid duplicating focal lengths in your collection – there’s a reason Canon offers an 11-24mm, 24-70mm and 70-200mm trio in its professional lens range.

SEE MORE: 10 things to look for when upgrading your standard lens

What is ‘equivalent’ focal length?

Focal length is the distance in millimetres from the optical centre of a lens to the focal point on the camera sensor. It’s a physical property of the lens and doesn’t change. What can change is the ‘angle of view’, which depends on the camera it’s attached to.

The angle of view is essentially what the camera sees through the lens. As the name suggests, a wide-angle lens gives extensive coverage. Extreme wide-angle lenses, such as fisheyes, can capture an angle of view of around 18°!

Telephoto lenses have a much narrower angle of view – a 500mm lens may only provide an angle of view of 5°, for instance, but that means that distant objects appear larger in the frame.

However, these measurements only count when the lens is attached to a 35mm film camera or a digital camera with a full-frame sensor. The majority of digital cameras use smaller sensors, and these capture a smaller portion of the image projected by the lens.

To find out the equivalent focal length – or the focal length that would give the same angle of view on a full-frame camera – you need to know the crop factor of the camera.

SEE MORE: Angle of view: how to choose the right focal length to frame your image

Crop factor?

This is basically how much smaller a camera’s sensor is than a full-frame one. For instance, the APS-C-sized sensor in a Nikon DX SLR is 1.5x smaller than a full-frame FX sensor.

To find the equivalent focal length of a lens attached to a DX camera, you need to multiply the focal length by 1.5, so a 50mm lens would offer an equivalent focal length of a 75mm lens on a full-frame camera.

While smaller sensors have obvious benefits when you can’t get close enough to subjects, such as wildlife, there are drawbacks when shooting landscapes and other situations that require wide views.

The post Best focal length for your type of photography appeared first on Digital Camera World.