Swapan Mukherjee, EFIAP, FFIP
It may now be confidently said that the number of nature photographers having inclination towards close up and macro techniques of taking images of small living objects like insects, mushrooms, flowers etc., are increasing day by day. My inspiration in this field may be attributed to famous photographers like Mr. T K Dutta from Bengal, Mr. T N A Perumal from South India and some legendary workers of our time.
What is close up and Macrophotography
When the subject to be photographed is small, we need to go close to it for taking a good and adequately large size of image. Large images can also be obtained by using special equipment which I will discuss later. The term macro is used to define images which are of 1:1 magnification on the camera format, be it electronic or film.
Any good DSLR camera may be used for close up or macro photography. Almost all prosumer and digital cameras have close up options which may be used for close photography.
Attachments are available for using with DSLR cameras for close up photography. The simplest of them is a set of close up lenses. The set comprises 3 to 4 lenses of different diopters for different size of subjects. These lenses are fitted on the top of the camera lens on its filter thread.
The second option is to use a set of extension tube or extension bellow. Extension tubes are to be fitted on to the body of the camera between the body and the lens. These tubes serve the purpose of taking the lens farther from the body of the camera enabling it to go close to the subject for getting a much larger image.
The use of a tele converter may help to take an even larger image. The sequence of fitting will be camera body + tele converter lens + extension tube + camera lens.
An important point to be noted here is that using a close up lens does not incur any loss of light, but an extension tube does it depending on its length. The calculation is as follows—
Magnification (M) = Extension / Focal length of the camera lens ( set at infinity) and the exposure factor is square of (M+1).
E.g. if we use a 50 mm extension tube with a 50mm lens, the magnification is 1:1 (life size) and the exposure factor will be (1+1) square= 4 (2 stops). An important derivation from this is that we can have high magnification even from a distance by using a long focus lens with a long extension. E.g. a 300 mm lens with a 300 mm extension will give 1:1 magnification from a good distance. An extension bellow does the same function for us giving an extra facility of continuous extension lengths unlike extension tubes.
Focusing is very important in macro and close-up photography. As we are required to take the camera very close to our subject, the depth of field becomes extremely shallow. Even if we can avoid camera shake or subject movement, only a small part of our subject will be in focus in most cases. To obtain greater depth of field the aperture is to be set at as small as possible. This again will reduce the available light and if we use extension tubes the loss of light will be more. The best solution to this problem is using an electronic flash unit, which deserves detailed discussions.
Using an electronic flash unit
As we have already seen that the use of an electronic flash unit is a probable solution to certain problems, let us go into the details of them. The light produced by an electronic flash is strong and taking it to very near to the subject allows us to use the smallest available aperture of the camera. This may increase the depth of field to the desired level. Sometimes, we can also use diffusers on the flash unit’s light emitting area to increase the quality of the light and restrict creation of harsh and high contrast images.
The knowledge of the technique of using one or multiple flash units is very important. Body textures of small insects may be missing if we throw flat flash light directly. Experiments will show that we can have much better images with shadow of the tiny textures by using light from a certain angle. Multiple flashes may also be used for subduing the deep shadows, compensating the difference of light on the other side etc. Sometimes, ring flashes are used for close up photography, but as ring flashes throw light from all sides encircling the lens of the camera, flat, shadowless images are likely to be produced and body textures of tiny insects will be lost. Experiments, however, can be made by covering selected portions of a ring flash. Finally, it is to be remembered that a lot of trial and error experiments are required to produce a good image of a very small object. These experiments are to be done with still objects and some standards are to be set up before using them in the actual field where we may be required to take decision and shoot within a fraction of a second.
The next higher stage of taking photographs of extremely small objects with a camera is photo-micrography. Photo-micrography is performed by fitting a camera on to a microscope. This enables us to take photographs of tiniest of objects like plant and animal cells, transparent cross sections of different objects etc. The subject deserves an elaborate and detailed discussion and is not in the range of normal macro photography.