When shooting insects in nature, one faces a number of challenges. One is the eternal trade-off between motion, light and depth of field. Another is focussing on a small moving target.
Depth of field
When the camera is very close to the subject, as in macro photography, the depth of field can shrink to a mm or less, and it becomes difficult to get the whole insect, or even part of the insect, in focus. Here are several solutions:
1: Set the F-stop as high as possible: nothing less than 11, better nearer 20, ideally more – depending on other factors, like the size of the insects and available light.
2. To get more of the insect in focus, align it side-on.
3. Line up all the important bits so they are the same distance from the lens, and allow ‘extraneous’ bits get out of focus.
4. Stacking: take two (or more) photos of the insect in the same position, but focus at different levels, then copy the sharp bits from one photo to the other. This usually only works when the insects is sitting still.
A form of ‘stacking’ can even be done on two completely different images:
Macro photography magnifies movements: whether it is the insect that moves, or a breeze blowing the leaf it is sitting on, or your hand that shakes because you are squatting in an awkward position…
1. Speed: turn up the speed, ideally to over twice the focal length of your lens (i.e. a 100mm macro needs at least 1/200th of a second, ideally more).
2. Fridge: some people like to refrigerate insects to slow them down temporarily. I don’t find this method very useful. One, where are you going to find a fridge when you are out in the bush? Two, how long do you leave it in for? Three, they end up in unnatural, dead-looking postures. Four, they warm up real fast, so by the time you have ‘arranged’ their limbs to look more ‘natural’, they are waking up. Having said that, I have used this method successfully on one or two occasions.
3. It is more useful to trap the insect under a glass, on a suitable substrate, and then simply watch and wait. They do eventually get tired from all the rushing about. In the meantime, get your camera ready and focused. When the insect stops to catch its breath, carefully remove the glass and shoot. When they start running, simply put the glass back. Repeat, until you get the perfect shot…
4. Hyper-active insects can sometimes be subdued with a bribe: place a drop of sugar water on the substrate (in this case I had chosen a smooth stone) and move the jar over the drop. Wait for the insect to start drinking, then carefully remove the jar and take your shot.
5. To shoot insects on flowers or leaves, when there is a breeze, operate the camera with one hand and hold the flower with the other. Just don’t jerk the flower in an unnatural, non-breezy way that will startle the insect.
High speed and high F-stop settings reduce the amount of light available, resulting in an underexposed photo in all but the brightest sunlight. What to do?
1. Increase the ISO setting. At super-high ISO the picture ends up grainy, but often photo clarity is still totally acceptable at ISO 2000 or even higher. Play around with your camera so you know what results to expect.
2. Insects often have shiny exoskeletons which reflect the sunlight unpleasantly, hiding interesting patterns and colours. In such cases muted sunlight or light shade works better, if you can arrange it.
3. In the absence of sunlight, the obvious – and often the only – solution is using a flash. However, the flash comes with its own set of problems (more about this in the next installment).
Combining these in the field
I usually start by taking a ‘recording’ photo’ (“I saw this insect”) using a flash with the following settings: F22, 1/200s, 200 ISO (on my 100mm macro lens). Easy numbers to remember.
Then, if there is enough light, I set ISO to auto, and take some more photos at F11+, 1/200s (or more if there is a breeze) – assuming the insect is still there of course.
If light conditions are such that the ISO goes above 6000, I set the camera to manual: 1/200s, f-stop 11 (or 8 in an absolute emergency), ISO as high as possible without ruining the photo due to graininess. If the photo ends up vastly under-exposed, this can often be fixed in an imaging software.
I use the auto focus only on large insects that are sitting still. For instance when shooting basking butterflies with a tele lens.
The rest of the time I ‘lock and rock‘ in manual focus. Meaning I focus approximately, then fine-focus by moving the camera back and forth ever so slightly, closer and nearer to the insect. (I don’t try move my entire head with the camera. Such movements are too clumsy. I keep my body still and move the camera closer and nearer to the eye.)
If the insect is perching on a branch or flower, I may operate the camera with one hand, and fine-focus by moving the perch with the other.
It is terribly easy to jerk out of focus just as you ‘pull the trigger’. The trick is to keep one’s body dead-still, by sitting or kneeling good and proper, not squatting precariously, by leaning on elbows or against something, by leaning the camera against a solid object, or using a spare hand, wrist or knee as a temporary tripod.