A small number of the photographs were obtained outside in the wild, but I have to admit that the great majority were taken indoors under quite artificial conditions. This is not as I would have preferred, but any idealistic resolve to limit the photography to stalking nocturnal moths after dark under wild and natural conditions would have been unrealistic and most of the photographs would never have been taken. Aside from the nocturnal habits of many of the subjects, another difficulty is that, at the small distances needed for insect photography, the depth of field is small, and the constant motion of an insect in the seemingly ever-present wind brings it in and out of focus continuously. I have used a macro lens indoors; it is possible that a telephoto lens might be a better bet for outdoor photography.
Butterflies and moths are active creatures and not very patient subjects for studio photographers. Most of my adult insect subjects have been newly-emerged from their pupal stage, as soon as their wings have hardened and before they have taken their first flight. This means that I have reared the insects from their larval stage, or from eggs; this in turn implies that many of the photographs have taken years to obtain, since I had first to find the caterpillars, and then to see them through to their adult stage perhaps a year or two later. All of the photographs are of living insects, and none have been anaesthetized or cooled. All have been released in suitable habitat as soon as they show signs of becoming active - often before I have been able to obtain a successful photograph. Persuading a butterfly to open its wings indoors in the absence of direct sunlight is a problem. I have found that gently touching (not repeatedly prodding) them near the inner angle of the hindwings will sometimes persuade them to open up long enough for me to press the shutter button.
Caterpillars are generally easier to photograph than adult insects, but the ideal photograph is not easy to obtain, and I have rarely achieved it. Sometimes a caterpillar is constantly in motion. At other times, especially if it has been disturbed, it will sit quite still. This will enable a photograph to be taken, but not an ideal photograph. Ideally, one wants to photograph it while it is in the act of eating. Only patience will enable this. Many caterpillars, especially geometrids, will not eat during daylight hours, and it is best to photograph them in the middle of the night.
The camera I use is a single lens reflex camera, equipped with extensible bellows. The photograph is taken with an electronic flash. The shutter speed is always 1/60th of a second, though the actual exposure time is the much smaller duration of the flash. The tripod and bellows-holder have many degrees of freedom, allowing me to translate or rotate the camera in many different ways.
The right degree of exposure is determined by the distances of the flash and the camera from the subject. This varies with the size of the insect. A small insect requires a high magnification; the bellows are opened to nearly their full length; the camera lens and the flash are close to the subject. For a large insect, the bellows are compressed, or even removed; the camera and flash are far from the subject. It should be possible to work out a table of flash distance versus bellows extension. In practice, I have not done this. Instead I rely on previous experience and I take at least three exposures with different flash distances. For eggs, I add extension tubes to the bellows, and the camera is then enormous. The lens and flash are then just inches from the egg.
The film I use is high-speed Ektachrome, currently marketed under the name
"Elite". This is a good film, though I dare say there are others that
are equally good. I have stuck to the one type merely because I am used to it
and know what to expect. Other photographers may well prefer to experiment with
different types. The film I use gives good colour rendering with flash. Some
films are designed to give good colour rendering in natural sunlight. The film
produces a positive transparency suitable for slides. Other colour films produce
a negative transparency; these are more suitable if the intent is to make colour
prints rather than slides. A good photography store can advise on which films
are for flash, which for sunlight, which are positive, and which are negative.
Because I use a small aperture, the film has to be fast. For many of the photographs,
the film was rated ASA 200. More recently, a similar film with a rating of ASA
400 was introduced. Traditionally, faster films have been grainier than slower
films, so photographers have been cautious about choosing very fast films unless
they really need them. Modern fast emulsions have improved so much, however,
that I have found the ASA 400 rating perfectly satisfactory and I have not had
trouble with too coarse a grain.
I usually have the insect on a twig in a vase on a small table in front of the camera. The blue background in many of the photographs, I regret to say, is not the blue skies of sunny Victoria, but is a sheet of blue card! I keep some pieces of bark for photographing moths as if they were settled on a tree trunk. A small point is that I keep a fairly large number of pieces of bark, otherwise sharp-eyed readers would be sure to notice that a huge variety of different moths were always sitting on the same tree trunk! I nearly always have the aperture closed down to f/16. The reason for using the small aperture is to gain sufficient depth of field. With wider apertures it is difficult to have the entire insect in sharp focus. So, why not go the whole hog and close the aperture right down to f/22? Well, for one thing you then need much more light and have to hold the flash too close to the insect for its comfort. In addition, the depth of field is then too great, and the texture of the blue cardboard appears in sharp focus and the awful deception is revealed!
One problem with flash photography is that the flash tends to produce hard, sharp, dark shadows. To try to circumvent this, I place reflectors of aluminium foil on both sides of the subject in an attempt to fill in these shadows. This has often helped, but has not always been entirely successful.
The results are a long way from perfection, but perhaps this description will give someone who wants to try insect photography a start in the right direction, so that he or she can take it from there and work out additional little tricks to overcome the problems that arise.