When it comes to gadgets and gizmos, one of the things that makes a huge difference – but is often overlooked – is the humble extension tube, writes Jon Adams. If you’re not familiar with these contraptions, they are hollow tubes with a lens mount on one end and a camera mount on the other, and they fit between the camera body and the lens to increase the distance between the optics and the sensor.
The result of this jiggery-pokery is that the lens will now focus closer than before, so the use of a tube reduces the minimum focusing distance of the lens. Any lens can be used, and although it will no longer focus on infinity with a tube fitted, it will let you get closer to the action. This makes extension tubes an ideal investment if you’re after some great close-up shots of garden blooms, but haven’t yet taken the plunge and stumped up the cash for a far more expensive macro lens.
Although you can buy tubes singly, the best value can be found by getting a set of three. With a set, each tube has a different length, so you can use them alone or stack them together in various combinations to get different extensions, and hence, different magnifications.
Most people use extension tubes with wide or standard lenses to boost their magnifying power. But extension tubes can be used to reduce the focusing distance of long lenses, too. So if the long end of your telephoto zoom has a minimum focusing distance of 2m or so, then fitting a tube will reduce this, allowing you to fill the frame with your subject. This is a great solution if you’re shooting smaller floral subjects with a long lens.
In this video, which we made for tube manufacturer Kenko a while back, Jon explains all this stuff, and shows how tubes are fitted and used to get great results. Although it’s had about 80,000 views on youtube, for some reason we never got round to sharing it with you, so here it is!