Transforming Ordinary Lenses into Super-Macro Lenses 🙂
This is Part I of a 3-part series on “beyond 1:1” macro photography. This crab spider has a 4mm body and a 7mm legspan. It would fit completely on your pinky-finernail. She is too small to capture, in this much detail, using a standard 1:1 macro lens. So the question thus becomes, “How do we capture an image like this using standard macro equipment?” The simple answer is, you can’t. A standard macro lens would only be able to get ¼ this close (36mm) and we would lose critical detail trying to ‘crop’ the image to bring her in close. I had to ‘fill a 36mm frame’ with 9mm of space, to give a little room around the 7mm legspan. This brings us to the topic of this blog entry: Professional-Level, Reverse-Lens Macro Photography.
Reverse-lens macro photography is the act of taking a standard prime (or zoom) lens, and reversing it, connecting the filter threads of the front element to the camera (via an adapter) and leaving the rear element protruding outward toward the subject. The goal in doing this is to achieve extreme magnification, inversely-proportional to the width (focal length) of the lens. That is, the wider the lens is, properly-oriented, the closer it focuses, when reversed. In other words:
- A 50 mm lens generally reverses to 1.1x magnification;
- A 28 mm lens generally reverses to 2.1x magnification;
- A 20 mm lens generally reverses to 3.4x magnification, etc.
So How Close Should you Go?
This brings us to the subject of magnification, and trying to visualize what degree of magnification we seek. Before we proceed, keep in mind this article is being written with respect to a full-frame sensor size (36 x 24 mm). If you have a sensor-size different from this (APS-C, 4/3rd, etc.), then you will have to do your own math, with respect to your particular sensor-size, but the principles here will still apply. That said, with a full-frame sensor, when we speak of 1:1 (or 1x magnification), what this means is when we use a standard 1:1 macro lens, at its closest-focusing distance, we will ‘fill our 36 x 24 mm frame’ with the subject. If we’re only at 1:2 (half-lifesize, or .05x) magnification, then we’re capturing a 72 mm subject across our 36 mm sensor. If we’re only at 1/4 lifesize (or .25x) magnification, then we’re capturing a larger 144 mm subject across our 36mm sensor. Makes sense? Good.
However, when we use a ‘super’ macro lens, we do the opposite. rather than moving away (to half-size), we are now moving-in passed the standard 1:1 macro reproduction rate, to achieve a 2:1 (or 2x lifesize) magnification level. This means we’re ‘filling the frame’ with a mere 18 mm subject. If we move in even closer, and go to 4:1 (or 4x lifesize) magnification, now we are filling our 36mm frame with a 9mm subject, such as the tiny crab spider female up top. With this paradigm in mind, when we decide what magnification (or reproduction ratio) we want to achieve, we need to take the size of our subject into consideration. As a visual, I have created markings on a ruler to illustrate:
Using this visual, above, we can see that a standard 1:1 macro lens will allow us to capture a subject that fits within the green 36mm frame. This tiny area will comfortably-fit a variety of small subjects (e.g., small butterflies, most beetles, wasps, bees, etc.) Meanwhile, some macro subjects might be too large to fit within the green 36mm sensor-size (larger butterflies, praying mantids, grasshoppers, snails, etc.). Therefore, for these larger subjects, backing-off to 1:2 or even 1:4 will be necessary in order to capture the entire subject on our 36mm frame. However, sometimes we are faced with the opposite situation: we need to move in closer, passed 1:1, in order to achieve 2:1 or even 4:1 lifesize magnification—or beyond. There are many small arthropods (spiders, flies, ants, aphids, even tiny flowers), for which a standard 1:1 macro magnification is simply inadequate to “fill the frame” with these diminutive subjects . Therefore, in order to move beyond the limitations of standard macro lenses, Nikon has created reversing-rings, which allow you to invert wide-prime lenses (as well as zooms), which thereby enables you to achieve magnification levels not possible with standard macro lenses. However, there are some limitations here too (to be discussed below).
While many of you have heard of (and/or read articles about) reverse-lens macro photography before, most articles on this subject are usually directed at young, inexperienced photographers, without much means, and as such these articles typically attempt to recommend ‘the cheapest’ (and least-capable) gear possible for these entry-level readers. This article will be different; it will be directed to those photographers not on a budget–but who are after optimal results with really good equipment. Mind you, this equipment doesn’t have to be ridiculously-expensive; in fact, most of it is no more expensive than usual pro glass. Nonetheless, the focus of this article will be quality results over ‘cheap price.’ Since Nikon has so many wonderful, manual-focus lenses available (either brand-new or available at discounts on Ebay), take your time and look for the best option; just make sure you know enough about Nikkor lenses to buy wisely:
Nikkor AI-S manual lenses are Nikon’s best MF glass. Do not buy Series E lenses, as they are not the same quality, either in craftsmanship or in results. Nikkor AI-S primes will always have The Ear on them (refer to green arrow above). Although my direct experience reversing standard primes to achieve super-macro objectives centers around Nikon gear, as with sensor size, the principles will apply across platforms, to any system, provided the brand you use has the associated supportive connecting pieces. One more thing: many people ask me, “Why Nikkor AI-S manual lenses? Why not auto-focus lenses?” First, manual focus lenses are tougher, less-complicated, and are optically as good as (or better than) most AF lenses. Second, you lose all aperture control when you reverse-mount an AF lens … whereas you can still control the aperture on Nikkor AI-S lenses, even when they’re reversed. With that said, let’s jump right in and discuss the simple rings/adapters required to convert Nikkor AI-S lenses into “super-macro” tools:
Putting the Pieces Together:
Now that we’ve discussed the concepts, and magnifications, let’s get into the material components necessary (1) to reverse your AI-S lens onto your Nikkor and (2) how to protect the exposed rear element—by creating a make-shift lens shade:
Moving from 1:1 to 2:1 with the Nikkor 28m f/2.8 AI-S:
There are basically two additional pieces you will need to go along with your AI-S lenses: the Nikon BR-2A adapter and the Nikon BR-3 adapter. One attaches to the front filter threads of your lens, allowing the reverse-mount, the other acts as a lens hood for the exposed rear element. Once you connect the pieces together, you are now ready to take “super macro” images:
Keep in mind that Nikon’s standard front-filter size is 52mm. This is the dimension around which the BR-2A is based. The important lenses that you can reverse mostly have this dimension as well, including the 55mm f/2.8 Micro AI-S (1x), , the 50mm f/1.2 AI-S (1.1x), the 35mm f/1.4 AI-S (1.8x), the 28mm f/2.8 AI-S (2.1x), and the 24mm f/2.8 AI-S (2,6x). However, if you want to get even closer, you will need to move to a Nikkor 20mm AI-S (3.4x), but this now needs an additional adapter: the BR-5:
The BR-5 allows you to thread the 62mm front filter of the 20mm AI-S to the BR-2A (52mm), which in turn then mounts onto your camera. Thus assembled, your setup looks like this:
Now that we’re ready to shoot super-macro, let’s discuss some of the factors to be aware of when we shoot ultra-close.
Now then, this article has formed focused around prime lenses; however, for the field, and because the need for magnification can vary, it is often more convenient to use Zoom-Nikkors, which brings us to the next phase of this discussion: The Ultimate Field Macro Super-Zoom
** UNDER CONSTRUCTION ** (Anticipated completion date: August, 20)