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 macro couplers.
Non-product photos © Todd Vorenkamp
What Is a Macro Coupler?
The macro coupler works in a similar fashion to the reversing ring. The difference is that, instead of mounting the reversed lens on the camera, you are connecting a reversed lens to the front of another lens that is, in turn, mounted on the camera.
You can mount two lenses of the same focal length together, or, if they have different focal lengths, you should mount the longer focal length lens on the camera and then use the coupler to mount the shorter lens in front of the longer lens.
What Are the Benefits of Macro Couplers?
Like our other “Macro on a Budget” options, cost and portability are the primary benefits of the macro coupler. A macro coupler ring is even slimmer and lighter than a reversing ring—perfect for unobtrusively carrying with your kit for those close-up photo opportunities.
The macro coupler does not add any additional optical elements to the setup, but don’t get too excited, because we will talk about optics in the “cons” section next.
Another (slight) advantage is that the innermost lens, if compatible with your camera, will maintain electronic communication with the camera for exposure information (autofocus will not be working through two lenses). In the digital days of live view and instant image review, having this metering information is not the advantage it used to be.
And, as with the reversal ring, because you are connecting the outer lens via a filter thread you can screw on any type or brand of lens as long as the filter size matches up.
What Are the Possible Drawbacks of Macro Couplers?
The first drawback is, simply, that you need two lenses to use the coupler. If you want to turn a single lens into a close-up lens, you can stick with extension tubes, close-up filters, or a reversing ring.
The laws of light say that, in general, the more optical elements through which light must pass to get to the sensor, the greater the chance of optical anomalies occurring. With a macro lens coupler connecting two lenses, you are adding an entire lens worth of glass between your subject and the sensor or film. Also, it is a fair bet that the lens’s optical engineers did not design the optics with the thought that the lens would be mounted backward on the front of another lens. It goes without saying that there can be some funky interaction as the light travels through a reversed lens and into another lens.
Need we mention here that we are not going to get the true flat field image quality of a dedicated macro lens when we are shooting through two different lenses (one backward)?
As with reversing rings, the macro coupler is a great match for your older manual focus and manual aperture ring lenses because, unless the inside lens is compatible and electronic, you will only have the option of manual focusing and aperture adjustment with this setup. Modern electronic lenses might not allow you to adjust focus or change the aperture when mounted in reverse on the camera or another lens.
Remember, similar to reversing rings, when you mount a lens on a rig via the filter threads, you are mounting the lens in a manner it was not designed to do. I would avoid mounting large, heavy lenses with a macro coupler (or reversing ring) because you do not want to damage the filter threads. Also, since the front lens is mounted in reverse, be careful where you point it, since the formerly rear end of the lens is going to be exposed to the elements and, since it was designed to be protected by the camera, may have parts and pieces that don’t react well to being exposed to the world.
Magnification
In a stroke of weirdness, the magnification math for a dual-lens macro coupler setup is fairly easy. To calculate the magnification of the rig, you simply divide the focal length of the longer focal length lens by that of the reversed, shorter focal length lens to get your answer.
If you mount a 50mm lens on the camera and then couple a 24mm lens to the threads of the 50mm lens, you will get a 2:1 reproduction ratio—double life-size. If you mount a pair of 50mm lenses together, you will get a 1:1 life-size reproduction.
Tips for Use
Macro couplers allow you to do some funky close-up photography with a pair of lenses. Here are some tips for using them.
Try different combinations: If you own more than two lenses, feel free to experiment with different combinations of lenses to see what kind of results you get when they are coupled. You might find that a certain magnification or aesthetic feel of an image fits your style better than others.
Work with manual lenses: Macro couplers are another great use for old(er) manual lenses, so dust off the ones on your shelf or grab one on your next flea market outing (or Used Department visit) and make some art with vintage glass. Also, connecting the outer lens via the filter ring allows you to expand the different types or brands of lenses you can use greatly.
Experiment with depth of field: Be ready to experience super-shallow depth of field when your coupled lens rig produces 1:1 or greater magnification—this is simply the nature of high-magnification close-up photography. Check out my article on macro depth of field for some ways to counter (or embrace) it.
Couple It!
Is a simple lens reversal too boring and old hat for you? If you said, “Yes,” then grab a macro coupler and start experimenting with close-up photos with two different lenses mated in front of your camera. You never know what kind of powerhouse macro franken-rig you might discover!
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: extension tubes, close-up filters, and reversing rings.
Do you have any questions or thoughts about macro couplers for close-up photography? Let us know in the Comments section, below.
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