I enjoy working with different equipment to get ‘close’ to subjects with a camera, but I especially like adding thin extension tubes to shorter focal length lenses to create wide angle close-ups.
Adding extension tubes between the lens and camera adds macro capability to different lenses I already work with. In addition to a TTL adapted ‘kit’ of three extension tubes—a 12mm, 20mm, and 36mm—I also have a manual 8mm Nikon PK-11A. Note: All of the products mentioned in this article are available from the Macro Photography store at Adorama.
Wide angle puts subject in context: The closeup of the prickly pear blossom, above left, shows how a a 28mm lens with an 8mm extension tube can include the background—in this case, Badlands National Park—to dramatic effect. The same set-up's depth of field allowed me to get the rainbow cactus blossom at left, shot at Big Bend National Park, in sharp focus close up.
The shorter the focal length, the thinner the extension tube, is a general rule of thumb for selecting extension tube lengths. Tubes can also be combined for longer focal length lenses. I’ll often combine the 20mm and 36mm when working with a 200mm lens to get really close in on a subject. If the extension tube is too long for the focal length, there won’t be any sharp focus at all. As with any macro lens, the amount of depth of field decreases considerably when using extension tubes.
The shortest macro capable lens is generally a 60mm focal length, and both 8mm and 12mm extension tubes can be used with shorter focal length lenses to shoot landscape macros that have greater depth of field for the main close-up subject, and when using a small aperture also provide a sense of the background landscape. The shorter focal lengths let you get really close-up with larger subjects, while still giving soft background detail. While a 12mm tube works with Canon and other major brand with focal lengths down to 35mm, Nikon’s 8mm extension tube will even work with a 16mm fisheye lens.
The wider the lens, the more foreground-background interplay, as you can see in this full-frame shot of a cecropia caterpillar, made with a 24mm lens and 8mm extension tube.
While the 12mm tube has TTL contacts, there are none on an 8mm Nikon tube. In order set a lens aperture with the 8mm tube, you need to work with a lens (prime or zoom) with a manual aperture ring and focus. This also requires working in Manual Mode to set the exposure. Adjust the lens aperture to the desired depth of field (greatest DOF at the smallest aperture / largest f /number), and then change the shutter speed (and possibly the ISO) to adjust the exposure. Exposure compensation can be used to fine tune exposure, and bracketing features should work normally. However, the depth of field preview button won’t work either. To check subject sharpness, take a photo, check the composition and the exposure, and then check depth of field sharpness throughout the subject area by zooming in to just before the image pixelates on the LCD. Then check detail sharpness both near and far throughout the main subject area.
The shorter the focal length, the closer the focus point when using a specific thickness tube. With a 16mm lens and 8mm tube, the focus point is right in front of the lens. A 24mm lens works really well for the macro subject size, focusing distance, and relative background detail. Since it also works well for extreme close-ups with the reversing adapter I wrote about previously, it becomes versatile extra lens in the camera bag for two different types of close-up photography.
Infinity isn't infinity: I focused my 35mm lens mounted on a 12mm extension tube at infinity which, due to the extension, became just one inch from the flower. At f /22 the depth of field was 1-1/8 inches.
Wider for more depth: With a 24mm lens mounted on an 8mm extension tube I focused at infinity which, thanks to the extension tube, became two inches away. I shot this at f/22 for about 1 1/2 inches of depth of field. The fraction of an inch and wider field of coverage made a difference in the final compositon!
Composing a wide angle macro is more like working with a full landscape image, since background detail is also included in the final composition. Sunny conditions can work as well as soft light conditions; just compose for the mood of the moment. Light and dark areas draw the eye, so be sure to balance opposing contrasts in different areas of the image to draw the eye from one location to another. Fill flash, underexposed by about a stop, can also help accentuate the nearby subject, as well as give better color rendition.
Subject motion is a major issue when photographing close-ups in the outdoors landscape. Since waiting for a subject to stand still long enough for an exposure can be almost impossible sometimes, try propping the subject with a twig, or hold it still with a small clamp. Remember to to use the camera’s Mirror Lock-up feature so there is no noticeable camera motion as well. With the extreme magnification in a macro image, even a well dampened mirror swinging up can cause noticeable motion in the final image.
When shooting with a wide-angle lens on an extension tube, compose each shot as if it were a landscape. On this scene I used a 35mm lens mounted on a 12mm tube.
For a tripod, a Gitzo 6X, 4 section Explorer, and Off Center Ballhead, all available from Adorama, gets the camera down to ground level easily, and has easy adjustments to place the camera, and hold it firmly in place. While the combination is one of the pricier tripod/head combinations, it’s the sturdiest and most flexible set-up I’ve come across for all the landscape photography I do, including close-up as well as distant images!
24mm lens on an 8mm extension tube lets you go for some unexpected juxtapositions.
Experiment! While shooting at f/22 gives the best depth of field, wider apertures offer options for narrowing the field of focus to more specific elements. Try adding close-up diopters to add some extra magnification and narrow the field of view. There are also some close focus, wide angle lenses on the market that have reasonable macro capability.
Get down! This magic mushroom becomes a towering forest fungus, thanks to 24mm lens mounted on 8mm lens. Shot with an APS-sensor camera.
One of the most intriguing elements of photography for me is the extensive range of options available for shooting. Each new option opens up new shooting possibilities as well as a whole new way to view and photograph the world around us!
Wide-angle lenses with extension tubes give you an entirely new way of looking at the world up close and a different way to compose your macro shots. 24mm lens on 8mm tube.