Photo Credit: by Cyrill Harnischmacher

Extension Tubes & Teleconverters

Extension tubes, as the name implies, are added between the camera body and the lens. They have no optical elements of their own, and only lengthen the extension of the lens. The advancement into the closeup range is only possible step-by-step through the combination of different extension tubes, which can prove to be somewhat cumbersome in the field. With an extension of 50mm, a magnification of 1:1 can be reached with a normal lens of 50mm. The image quality will strongly depend upon the lens used. Good results with a magnification ratio greater than 1:1 can be achieved when combining an extension tube with a macro lens. For practical purposes, we only recommend automatic extension tubes which transfer all functions between the camera and the lens.

A teleconverter changes the focal length of the lens by a certain factor through an optical system. For closeup photography this means that at the same focusing distance the picture will become larger on the film plane or sensor by the factor of the converter. If the same magnification ratio is kept, the focusing distance changes correspondingly. A 50mm closeup lens with a magnification of 1:1 will become a 100mm closeup lens with a magnification of up to 2:1 in combination with a 2x teleconverter.

If the magnification ratio of 1:1 is kept, the focusing distance to the subject doubles. Teleconverters are an economical alternative to the much more expensive telephoto closeup lenses. Since teleconverters reduce the amount of light that reaches the film plane, they should not be used under low light conditions. Expect to open up the aperture 2 stops with a 2x teleconverter, and approximately 1 stop with a 1.5x teleconverter. The viewfinder will also dim by the same factor. Some teleconverters are specifically made for certain lenses; this combination may result in very high image quality. In contrast to extension tubes, teleconverters do not cause lenses to lose their ability to focus on infinity.

Teleconverters extend the focal length, but they also affect the image quality of the lens.

Reversed Lenses

A lens can be mounted in a reversed position to the camera faceplate with an adapter ring. The possible magnification ratio with a 35mm lens will be approximately 1:1, and about 3:1 with a 20mm focal length. An adapter ring has a lens mount on one side and an external thread on the other side. When using an adapter ring, all automatic camera controls are lost, including control over the aperture, which makes working more difficult. Although you can focus adequately with an open aperture, you must manually stop down to take the picture. This darkens the viewfinder to an extent where it can be difficult to see the shifting point of focus when moving the camera. An alternative for owners of Canon EOS cameras is the Novoflex reverse adapter. It uses a cable and a second adapter ring to retain most available functions.

A stacking ring connects two lenses. The front lens transforms into a high quality macro lens. (This is also possible with digital bridge cameras as long as they come with a filter thread on the lens).

With the use of stacking rings, a second lens in reversed position may be attached in front of the primary lens, taking on the function of a high quality closeup lens. Stacking rings have two sets of threads in order to connect the lenses (front to front). It is best to use a wide-angle lens with a large aperture in the reversed position. If the opening is too small, the image frame may not be filled in its entirety or will be clearly vignetted.

With a reversing ring, lenses can be mounted reversed to the camera faceplate and used as macro lenses.

Bellows

Bellows are used to lengthen the extension of the lens by continuous adjustments, as opposed to the step-by-step process of extension tubes. Just like extension tubes, bellows do not influence the image quality of the lens because they do not have an optical system. Because extreme magnification ratios can be reached, it is often necessary to stop down significantly to acquire an acceptable depth of field. This leads to problems with diffraction. Besides specially developed lenses for bellows, closeup lenses with a focal length of 100mm are well suited for use with bellows. These lenses offer a working distance from the object that is long enough to set up effective lighting. Normal and wide-angle lenses should be attached in reverse. The bellows from Novoflex are particularly practical as they transfer the aperture settings to the camera, enabling you to work intuitively with a bright viewfinder. When combined with a flash, the camera may even be handheld. A disadvantage of all bellows devices when coupled with a DSLR camera is that the dust which tends to settle in the folds of the bellows may easily contaminate the image sensor. Therefore, it is important to clean the bellows thoroughly with an air blower before attaching them to the camera. Depending upon the extension and type of lens used, bellows devices allow for magnification ratios of up to 6:1.

Bellows allow magnification rates that go far beyond the ratio of 1:1. Some models even transfer the aperture setting so that you can focus with the aperture wide open, allowing for a bright viewfinder display.

Closeup Lenses
For digital compact and bridge cameras, closeup lenses are not only the least expensive, but are the only option for advancing into closeup photography. The focal length of the lens is shortened by simply screwing the closeup lens onto the filter threads. This allows for a shorter working distance from the subject, and therefore a larger representation on the film or sensor. The image quality depends not only on the quality of the closeup lens, but also on the photographic lens used. To achieve an optimal image quality, the lens should be stopped down by at least 3 stops. The best results are achieved with achromatic closeup lenses in combination with high quality fixed focal length lenses. Simple versions save you money but may not deliver good optical performance. Since clearly visible distortions and blurred edges can be present, these lenses should not necessarily be used for reproduction work. Closeup lenses also have many advantages. The speed of the lens is preserved, and therefore delivers a bright viewfinder image. They are lightweight, easy to handle, and can find space in every photo bag. They can be used in the wide-angle closeup range to create interesting perspectives.

Closeup lenses come in different versions. Their strength is measured in diopters between +1 (slight magnification) and +10 (very high magnification).





Together with a closeup lens (in this case +10 diopters), the standard zoom lens becomes useful for macro imaging. Because of the potentially powerful magnification, the shallow depth of field can be used as a creative element.

Specialized Equipment - Zoerk Macroscope
The Zoerk macroscope is an aspheric, 2-element, top-notch closeup lens with +12 diopters. The image quality clearly overshadows many basic closeup lenses, depending upon the quality of the basic lens used. A magnification of 1:1 is possible with an 80mm lens and a focusing distance of about 6-9cm (2.5-3.5 in.). This distance falls below the flight response distance of many insects and animals, yet allows enough distance between the camera and the subject for a supplementary lighting setup. When the macroscope is paired with a basic lens in the wide-angle range it might lead to vignetting. Like all closeup lenses, the macroscope is directly attached to the filter thread of the lens with an adapter. It is especially practical for use with zoom lenses. Even with a macro lens it performs admirably, bringing the magnification far beyond the ratio of 1:1. In combination with a digital bridge camera and an image stabilizer, it produces a wonderful and compact solution for closeup photography while traveling. Further information is available here.

The Zoerk macroscope is an aspherical, 2-element closeup lens of top-notch quality.

Canon Magnifying Lens
The Canon MP-E 65mm 1:2.8 1-5x Macro lens is a comfortable alternative to a bellows device. This magnifying lens is calculated for magnifications between 1:1 and 5:1, and thus, goes far into the closeup range with the highest image quality.

Fly consumes sugar. 1/125 sec at f/16; 50mm normal lens reversed on bellows; small flash LZ 22 manual with softbox. The depth of field is only a fraction of a millimeter, which makes it extremely difficult to pinpoint the optimal point of sharp focus. Here, the point of focus is on the sugar crystals as the most prominent detail in the picture. If it were to lie just slightly closer, e.g., on the edge of the fly’s head, the sugar crystals would be out of focus.


What appears to be a model landscape is actually a real street scene. The impression of a closeup picture arises by shifting the plane of focus and using a large aperture.

The Zoerk Multi Focus System
By matching the plane of focus to the subject, the Zoerk Multi Focus System may permit a shutter speed that can be used with a handheld camera.
The Zoerk Multi Focus System consists of a tilt tube, the Zoerk Mini Macro Mount, a camera adapter, and a lens head (generally an enlarger lens or large format lens). It provides up to 30 degrees of tilt and swing in any direction, similar to large format view cameras. Because of this you can adjust the plane of focus to suit your object; for example, across the whole length of a pencil lying diagonally. Alternatively, you can significantly increase the depth of field without having to stop down the aperture. The big advantage of this is the short exposure time, allowing the system to be used while handholding the camera. Focusing is done through the Mini Macro Mount (a cone-shaped focusing tube), which has the advantage of continuous focusing adjustments (as is the case with bellows), combined with the stability and compact construction of an extension tube. Since the exposure is measured on the working aperture, it is best to use the Zoerk Multi Focus System on a camera that preserves the automatic exposure mode even with manual focusing lenses. However, this is not always a feature found on modern DSLR cameras.


A professional photographer and designer based in Southern Germany, Cyrill Harnischmacher's first book Low Budget Shooting won the prestigious Fotobuch Award from the German Booksellers Association. Cyrill is a studio photographer by profession and a nature and infrared photographer by passion. His book Closeup Shooting is published by Rocky Nook and distributed in the United States by O'Reilly.