Stacking prime lens | Macro photography techniques
Stacking prime lens | Macro photography techniques | ||
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An alternative approach to using a supplementary close-up lens is to use another camera lens as the supplementary, 'stacked' onto the prime lens. This technique was popular 20 years ago, but seldom used today, though it is well worth experimenting with, as high magnifications can be obtained relatively easily, often with excellent results. The usual technique is to mount a medium telephoto lens (not a zoom, as their complex construction does not always give good quality in this case) on the camera body e.g., a 200 mm lens. Then mount onto the front of it a reversed shorter focal-length lens e.g., 50 mm. You will need a 'coupling' ring, available from several manufacturers, to enable you to join the two lenses together. A short extension tube can be improvised as a lens hood for the reversed lens. The power (in diopters) of the reversed lens is 1000/focal length. Thus, a 50 mm lens will have a power of +20, and a 100 mm lens will have a power of +10. The magnification obtained with this combination is approximately: M = Focal length of primary lens / Focal length of reversed lens For example, if the primary lens is 200 mm, and the reversed lens is 50 mm, then the magnification will be approximately 4× with both lenses set to their infinity setting. Keep the aperture wide open on the 'front' lens, and control exposure with the aperture of the prime lens. This combination is rather heavy and cumbersome, probably lending itself more to the studio rather than field work. | ||