Macro for starters

Macro Macro photography has acquired a number of definitions over the years. The time was when no selfrespecting zoom lens would be without a zoom-macro facility. In truth these were often outside the definition of true macro but the ‘Ad-men’ cottoned on and the description stuck! "Close-up" photography is usually deemed to start at magnifications of greater than 1/10th full size, that is when the image on the film or CCD is 1/10th of its real size. The reason for this break point was simple. In those days, before aspheric lenses, most conventional designs were limited to working down to 10 focal lengths. Macro Photography really kicks in at 1:1 magnification, when the image and the subject are the same size.

Photomicrography kicks in beyond 10x full size, the point at which more complex optical trains are required, as in the compound microscope. Basically the "objective" lens creates an image inside the microscope and this is in turn examined with another lens, usually an eyepiece in the microscope but the image can be diverted to a camera for photography. This gets to be a dear do, your editor once spent £25,000 of your government's money on one microscope, in the days when that was at least three times his salary!

The Special Properties of Macro Photography There are a number of things you should understand about macro photography, which might help save you some disappointment. The main problem is that you have to get very close to your subject and that subject is big in the frame. If your heartbeat is causing you to move 2mm and you are working at 1:1 magnification your blur streak is going to extend over 10% of the frame. So rule number one is that you have to get yourself rock steady. If your subject is also moving (e.g. a flower in a gentle breeze) you have to tie the beggar up or surround it with a windbreak!

Macro Lens The second problem is Depth of Field (DoF). This is the length of the zone of sharp focus in front and behind your subject. Parts of the image outside the zone get gradually more blurred. DoF's can be very small. For example if you are photographing a small butterfly you may need to work at ½ full size. At this magnification your DoF at a typical aperture could be as low as 5mm, not enough to sharply render both the wing tips and body of a Common Blue. Depth of Field is increased by using a smaller aperture but you need to compensate with increased exposure time, just the thing you don't need in windy conditions when things are swaying about. The solution is to use flash and here, for once, things go in the photographer's favour. The closer you get to your subject the relatively stronger your flash gets. It is not unusual to employ effective apertures of f45 or f64 in close-up work. That requires an exposure of 1/8th of a second in sunlight (as much as a second in the woods) so you can forget hand holding! By comparison a £20 flashgun used at macro distance can easily pump out enough light for f32. All of these problems do not present so much difficulty in the studio for say jewellery work as you can bolt everything down solidly.

The Ways and Means

Use your Digital Camera

Today's digital cameras often have good macro facilities built in. The Nikon Coolpix 995 is particularly good and can focus down to 2cm. That's the thickness of your thumb but don't forget that no self-respecting butterfly is likely to let you get that close so you will have to be more modest with your demands!

The Close-up Lens

Also known as a supplementary or dioptre lens, these come in a number of strengths, typically 0.5 dioptre, 1, 2 or 3 dioptres. They normally screw onto the front of your lens. You may have to focus manually with a digital compact using one of these. A feature of using a Close-up lens is that the working distance remains constant at 1000 divided by the strength of the lens. Hence a 3 dioptre lens will have a working distance of 1000/3 = 333mm. The magnification you end up with depends on the focal length in use. If you zoom to a longer focal length the camera can stay where it is, the image just gets bigger. For our example we simple stuck the lens to a Coolpix 995 with Blu Tack. This is a £7 solution but it works quite well so don't knock it!

The Extension Tube

This is a hollow tube, which simply spaces the lens away from the camera body. In an SLR camera it has to maintain a connection with the exposure meter and the aperture mechanism. If the amount of extension equals the focal length of the lens then you get 1:1 magnification.

The Teleconverter

Placing a teleconverter in between a lens and the camera body increase the effective focal length usually 1.4 times or 2 times (more rarely 3 times). This is very useful for shy subjects such as dragonflies as it increases your working distance or, if you move in, your magnification. In the studio it can create more space to insert lights and reflectors.

The Dedicated Macro Lens

The picture shows three optics, the 55mm Micro Nikkor, the 105mm Micro Nikkor and the TC200 Teleconverter. The prime lenses focus all the way down to 1/2x full size and then to 1:1 using the dedicated extension tubes. They are old but still perform wonderfully well, glass does not get tired from taking pictures! Despite their age (circa 1980) they fitted and worked on the latest Nikon D1 digital camera - that's what you call non-obsolescence, something Nikon have always been proud of.

Bellows

At the end of the chain in terms of building up magnification comes a bellows. These are like an infinitely variable extension tube except that they can be 200mm in length to give up to 10x magnification with the right lens. We chose to use a 75mm Enlarging Nikkor. This fits to the PB6 Bellows via a special adapter. We are talking 25-year-old kit here, still bitingly sharp and hitched up to a year-2001 camera. The only compromise we had to make was to add an extension tube to the back so that the big battery bays of both the film F4 and digital D1 cleared the back of the bellows.

One of the longstanding problems of macro was the calculation of exposure, you always had to either use a calculator or a pre calculated table. With a D1 you just shoot then read the histogram and what you see is what you get - what we would have given for this technology in the early eighties when we used to churn our way through £1000 of Polaroid each month?

Some Final Thoughts

mcro We have shown you the full range of close-up equipment but do not want to leave you with the thought that you can only achieve success with a heavy investment. In still life macro the most important thing is what you do with bits of card, silver foil and plasticine, lighting still counts for 80% of the mood of the shot. In the great outdoors, field craft is far more important than fancy cameras. If you are inept at approaching a skittish dragonfly it will not be on its perch when you shoot. It has no respect for the value or modernity of your equipment! Finding ways of keeping still are one of the greatest skills you can acquire. Use every trick in the book from tripods, monopods, canes, windbreaks, laboratory stands and convenient trees. Given half a chance flash will always improve your shot even if it is only to supplement the natural light.

The SWPP 2008 Convention was an outstanding success,
we have 44 days to get ready for the 2009 convention - which starts on January 14, 2009

Photo Quote: A positive attitude can really make dreams come true - it did for me. - David Bailey