Capture fine details using extension tubes
Many photographers are attracted to the idea of capturing revealing close-ups of flowers, insects and textured surfaces, but not everyone wants to invest in a dedicated macro lens
Many photographers are attracted to the idea of capturing revealing close-ups of flowers, insects and textured surfaces, but not everyone wants to invest in a dedicated macro lens. Fortunately, there are a few alternatives to specialist optics and one of the most popular comes in the form of extension tubes. These vary in both price and length and are produced by the main camera manufacturers and third-party manufacturers alike.
Extension tubes are typically sold in sets, with 12mm, 20mm and 36mm being examples of typical sizes. The longer the extension tube, the greater the distance that is created between the lens and your camera’s sensor. It’s this relationship that enables you to focus the lens more closely, producing a higher magnification than would otherwise be possible. You can use an extension tube with absolutely any lens, but a standard lens of around 50mm up to a short telephoto lens works best. Zoom lenses, wide-angle lenses and indeed dedicated macro lenses can also be used, but you can encounter problems with zooms and wide-angles because the front element of the lens is extremely close to the subject. There are two main types of extension tube: a cheaper, all-manual option and a costlier version that retains metering and autofocus capabilities.
Step 1 – Extension tube design
When you unbox a set of extension tubes, you’re presented with something that looks very much like a lens. However, there is no glass involved. Some extension tubes feature electric contacts, enabling autofocus and metering to function.
Step 2 – Select the right lens
You might find that the distance between the front element of the lens and the subject will be very small when using wide-angle or zoom lenses. Standard through to short telephoto focal lengths are ideal; you’ll see more of an impact when using a 50mm lens than a 200mm lens.
Step 3 – Attach the tubes
Extension tubes attach directly to the camera. Typically, they come in sets of different lengths, such as 12mm, 20mm and 36mm. The greater the tube’s length – and/or the greater the number of tubes you attach – increases how close you can focus.
Step 4 – Check your settings
Setting your lens to a narrow aperture is a must. Even using f16 or f22, you will still find depth of field is limited. A higher ISO or the use of macro flash may be necessary to avoid a very slow shutter speed, especially as the tubes diminish the light reaching the sensor.
Step 5 – Keep things steady
Even if you are able to avoid a slow shutter speed, it’s best to use a tripod when photographing macro subjects – no matter whether you are using a dedicated macro lens or extension tubes.
Step 6 – Frame your shot
Shallow depth of field can make composition and framing challenging, so take your time and be ready to move the camera’s position forward or back slightly in order to refine the composition and the focus.