Macro on a Budget: Extension Tubes

Close-up or macro photography is an incredible way to capture the tiny world around us on a super-detailed level. While the dedicated macro lens is still one of the best tools for exploring the world on a miniature scale, there are some very inexpensive ways to jump into macro photography with the lens or lenses you already own—no need for a specialized close-up macro lens. In this article, we will take a closer look (no pun intended) at extension tubes.

Non-product photos © Todd Vorenkamp
All photos taken with FUJIFILM XF 35mm f/1.4 R and FUJIFILM extension tubes

What Are Extension Tubes?

Extension tubes are metal (or plastic and metal) tubes that are mounted between a camera and lens to extend the physical distance between them. They are designed for a specific lens mount to attach mechanically to the camera and lens.

By physically extending the distance between the camera and a lens, you allow the camera to focus closer than its published minimum focus distance (MFD), allowing close-up photography. This allows you to use your “regular” lenses for close-up photography—no specialized or expensive macro lenses are needed!

While the closer shift in the MFD certainly allows you to get closer to your subject(s), it does not guarantee true macro (1:1) reproductions.

What Are the Benefits of Extension Tubes?

The biggest advantage of extension tubes is that they are simply hollow tubes. There are no optical elements inside them. Whenever light passes through a glass element, regardless of its near perfection, the light is bent in undesirable ways. The lack of optics in an extension tube means your lens’s optical characteristics remain virtually unchanged.

When compared to the cost of most macro lenses, extension tubes cost much less. Also, extension tubes, even if you have two or three, are smaller and lighter than almost any macro lens you will find on the market. This makes them an easy addition to your camera bag to use for spontaneous close-up photo opportunities. Not every photographer has room for an additional lens in their bag, but most can squeeze in a lightweight extension tube, or two, or three.

Also, if you already have a favorite macro lens, you can boost its magnification with extension tubes. They need not only be used on non-macro lenses.

What Are the Possible Drawbacks of Extension Tubes?

While the lens-less extension tubes do not give light extra hurdles to pass through before reaching the sensor, some (many?) lenses are not performing their best at their MFD. That level of performance, good or bad, will pass, untouched, through the tubes to the sensor. All lenses perform differently, even identical models, so there is really only one way to find out if your lens is up to the extension tube/close-up challenge—taking it out for a spin!

In almost every case, adding an extension tube, or tubes, to a lens means that the lens will not focus accurately at infinity or other long distances. This means that, if you want to take a photo of something farther away, you will need to remove the extension tube(s). Find a close-up subject. Slap the tubes between the camera and lens and get your shot. Back to “regular” shooting? Remove the tubes and reattach the lens directly to the camera.

Because of the expanded physical spacing between the camera and lens, there is the chance that you will get some vignetting of your images. This is often looked down upon, but sometimes it can subtly help focus the viewer’s attention on the subject.

Magnification

Ready for some fun with math? If you are curious, you can calculate your extension tube-armed lens’s new magnification with a simple equation:

Extension tube magnification formula = Lens’s Native Magnification + (Extension Distance / Focal Length)

You can get your lens’s native magnification from the specs section of your lens’s page on the B&H Photo website, and all extension tubes are labeled with their depth.

Example:

• FUJIFILM XF 35mm f/1.4 R Lens
• FUJIFILM MCEX-11 11mm Extension Tube
• FUJIFILM MCEX-16 16mm Extension Tube

Maximum Magnification 0.17x + (27mm / 35mm) = 0.94x

At 0.94x, the FUJIFILM 35mm lens with two extension tubes is almost a 1:1 (1x) macro lens!

Three Flavors of Extension Tubes

Are you ready to dive in? You might notice that there are a few basic genres (and price points) of extension tubes:

• Basic tubes without electronic connections
• Off-brand tubes with electronic connections
• OEM tubes from camera manufacturers with electronic connections

The electronic connections, in general, allow the camera to continue to communicate with the lens for aperture control and autofocus. While autofocus is not always needed (or wanted) for close-up photography, many of today’s modern lenses do not allow control of the aperture without an electronic interface. If you are using non-electronic tubes with these lenses, you are likely going to be capturing images at the lens’s maximum aperture.

If you are using a “vintage” lens with a manual aperture ring and manual focus for your extension tube/close-up adventures, then you do not need tubes with electronic connections.

Extension Tubes Change Your Focal Length and Maximum Aperture

Forgive me for possibly getting too technical here, but when I state these two definitions, you will see how the extension tube transforms more than the MFD of a lens.

• Focal Length: the distance from the lens’s optical center (or nodal point) to the image plane of the camera when focused at infinity.

• F-number: The ratio of the opening of a lens aperture when compared to the focal length of the lens.

Adding an extension tube (or tubes) to the lens effectively changes the focal length. Because the aperture is calculated with focal length as a variable, the lens’s f-numbers change, as well. Therefore, your lens’s maximum aperture f-number is no longer the same when tubes are added—it is smaller. You can see this in your exposure data and through your viewfinder as you will see an extension tube image will be darker than one without tubes.

Because of these physical changes to your lens, when you do close-up photography with extension tubes you will experience super-shallow depth of field and, since the image is darker, slower shutter speeds. This article discusses how do deal with depth of field with close-up photography. And the darker image runs the risk of an increase of issues related to camera shake or subject motion blur. You may need to boost your lighting, shoot in daylight, or adjust your aperture and ISO to keep your shutter speeds fast enough to avoid blur.

Totally Tubular!

If you want to get into close-up or macro photography, but do not want to invest in a macro lens, the extension tube is my preferred method for starting your adventure into the tiny world of close-up photography. You cannot beat the price point, portability, and versatility of the extension tube. Throw a tube or two in your bag for your next photo outing and a new universe of photographic possibilities is presented to you!

To see some shots with extension tubes in action, check out this article on macro photography gear and this one on extreme close-up photos.

In the other articles in this series—Macro on a Budget—we look at additions for your lens, or lenses, that allow you to explore the world up-close: close-up filters, reversing rings, and macro couplers.

Do you have questions or thoughts about extension tubes for close-up photography? Let us know in the Comments section, below.