Extension tubes (also known as macro tubes) are one of the most useful tools you can purchase for creative flower photography. An extension tube fits between your lens and your camera body. They are basically a hollow tube, made of plastic or metal, created for the purpose of moving your lens farther away from the internal sensor inside your camera body. An extension tube allows you to get closer to your subject and still achieve focus. You can fill the frame with the subject, eliminating the need to crop your image in post-processing.
Generally speaking, there are two kinds of extension tubes. Those that work with your camera‘s autofocus, and those that don‘t. I purchased a set of cheap non electronic tubes for under € 20 ten years ago and am still using them. It doesn‘t worry me that they disable autofocus as I normally use manual focusing for creative flower photography. If you are on a budget, then I recommend giving them a try.
Alternatively, Canon and Nikon (as well as other brands) make sets of active extension tubes with full electronic contacts, giving you full autofocus capabilities. As you‘d expect, they are more expensive, at approximately € 140 – € 230. If you think you‘ll use autofocus more than manual focus, then I recommend purchasing the more expensive option.
Photographing with Extension Tubes
You can attach the extension tube to the camera body, then attach the lens to the tube. Or alternatively, attach the extension tube to the lens first, then attach the joined components to the camera body. There is no right or wrong. Place your camera on a tripod and set the exposure dial to Manual mode. Set the switch on the side of your lens to manual focusing MF/M (if it has one).
Turn on Live View and rotate the focal ring until you see sharp focus on part of the flower. If you can‘t achieve sharp focus, try moving the camera closer or further away from the flower while looking at the Live View until you get better focus. Zoom in on the LCD screen to get a better look at the focused area and tweak the focus if needed. When you are satisfied with the focus, snap the shot.
Using an extension tube allows you to shoot closer to your subject (no matter which lens you use), which in turn also decreases your depth of field. i.e. you‘ll need to learn how to like, and control the amount of blur you see. This is the beauty of extension tubes. If you buy a set, you can join two extension tubes together to give you even more magnification. However I do recommend using them one at a time to start with before coupling them together for even more magnification.
One of the disadvantages is the loss of light caused by extending the amount of space between the sensor and the end of your lens. This means you‘ll be setting a longer shutter speed than normal.