Macro Lighting: Studio Lighting in Miniature
When people first try macro photography, there is a temptation to think that the main challenge is magnification.
Find a macro lens, move close enough to the subject, focus carefully, and surely the photograph will take care of itself.
In practice, I have found that lighting is often the more important problem.
The principles are not really different from conventional photography or filmmaking. We still have a main light, fill light, backlighting, side lighting, diffusion and control of shadows. The difference is simply that everything is happening on a dramatically smaller scale.
And at macro distances, moving a light by just a centimetre can completely change the photograph.
Much of the macro work I do uses the Adaptalux lighting system, because it lends itself particularly well to positioning small lights precisely around tiny subjects. That is useful not only for conventional macro photography but also for the scientific work we do: photographing specimens, organisms, crystals, electronics, experimental apparatus and all sorts of objects that are difficult to light using normal studio equipment.
Macro lighting is, in many ways, a miniature photographic studio.
And it is surprising just how sophisticated that tiny studio can become.
The Same Lighting Rules — Just Much Smaller
In a normal photographic studio I might think about three basic lighting components:
- the main or key light;
- a fill light;
- a backlight or separation light.
Exactly the same idea works in macro photography.
Imagine photographing a small beetle.
A light placed slightly above and to one side might become the main light, revealing the shape of its head and body.
Another weaker light from the opposite side can prevent the shadows becoming completely black.
A light from behind can illuminate hairs, antennae and the edge of the wings.
We have effectively created a three-point lighting arrangement.
The subject might only be 15 mm long, but the lighting principles are almost identical to those used to photograph a person in a studio.
The important difference is scale.
At Macro Scale, One Centimetre Is a Big Movement
When photographing a person, moving a studio light 2 cm is unlikely to transform the image.
When photographing something only 10 mm across, it might.
Move a tiny lamp slightly higher and a reflection may disappear.
Move it slightly sideways and a previously invisible surface texture suddenly appears.
Move a backlight a few millimetres and the edge of an insect wing may begin to glow.
That makes macro lighting wonderfully experimental.
I often find myself moving lights around the subject while watching the camera image rather than deciding in advance exactly where everything should go.
It becomes almost like sculpting with light.
Distance Matters Much More Than You Might Expect
One reason positioning becomes so critical is that light intensity changes rapidly with distance.
For a point-like light source, the approximate inverse-square relationship is:
Illumination is proportional to 1 / distance^2
So if the distance from the light to the subject is doubled, the illumination falls to roughly one quarter.
At macro distances, therefore, even quite small movements can have significant consequences.
Moving a light from 4 cm away to 8 cm away is not merely moving it a little further away.
It can dramatically alter the illumination.
This gives us enormous control — but it also means that macro lighting can be rather unforgiving.
The Main Light: Revealing Shape
The first light I normally think about is the main light.
Its job is not simply to make the subject bright enough to photograph. It is there to reveal shape, texture and structure.
Lighting directly from the camera position tends to flatten a subject.
Side lighting creates shadows.
Those shadows contain information.
Consider something as simple as the surface of a leaf.
Illuminate it directly from the front and the surface may appear relatively flat.
Move the light around to the side and suddenly the veins, surface hairs and contours become much more obvious.
The same technique works beautifully with:
- fossils;
- coins;
- bark;
- feathers;
- crystals;
- shells;
- circuit boards;
- fabrics;
- seeds;
- insects.
For scientific photography, this can be particularly important.
Sometimes we are not merely trying to make something attractive.
We are trying to reveal information.
Fill Lighting: Controlling the Shadows
Once the main light has created the shape we want, there is another problem.
The shadows may be too dark.
This is where fill lighting becomes useful.
The fill light is normally less intense than the main light.
Its purpose is not to eliminate the shadows completely. If it did, we would lose much of the three-dimensional appearance that the main light created.
Instead, the fill controls the contrast ratio.
For example, suppose I am photographing a small mechanical component.
A strong light from the left may beautifully reveal machining marks on the surface, but the right-hand side disappears almost completely into darkness.
A weak fill from the right can reveal enough detail without destroying the shadows.
The balance between these two lights can completely change the character of the picture.
Sometimes the Best Fill Light Is Not Another Lamp
There is another useful trick.
Use a reflector.
At macro scale the reflector does not need to be large.
A small piece of white card can be remarkably effective.
So can:
- aluminium foil;
- white plastic;
- silver card;
- a small photographic reflector;
- even a folded piece of paper.
Place it opposite the main light and it bounces some light back into the shadows.
This is particularly useful where there simply is not enough room to position another lamp.
Macro photography frequently involves solving exactly those sorts of spatial problems.
Backlighting Can Transform a Macro Photograph
Backlighting is one of my favourite techniques.
It is particularly powerful with translucent subjects.
A leaf photographed using front lighting shows its surface.
Light the same leaf from behind and suddenly something completely different happens.
The internal structure becomes visible.
Veins stand out.
Differences in thickness become apparent.
Edges can glow.
The photograph stops looking like a picture of a leaf and begins looking almost like a biological specimen.
The technique works equally well with:
- flower petals;
- insect wings;
- thin sections;
- translucent minerals;
- feathers;
- small aquatic organisms;
- droplets of water;
- fibres;
- some plastics.
This is where photography and scientific observation start to overlap.
Rim Lighting: Making Tiny Details Glow
A backlight does not necessarily have to shine directly through the subject.
Placed slightly behind and to one side, it can produce rim lighting.
This illuminates the outline of the subject.
With insects or plants, extremely fine hairs that are almost invisible under front illumination suddenly become obvious.
It can also help separate a dark subject from a dark background.
Once you start experimenting with rim lighting at macro scale, it becomes very easy to spend far longer than originally intended simply moving the light around and watching different structures appear.
Why Diffusion Becomes So Important
Small lights can produce very hard illumination.
That can be useful when trying to emphasise texture, but it can also create problems.
Many macro subjects are surprisingly reflective.
Think about:
- the polished surface of a beetle;
- a metallic component;
- a crystal;
- a drop of water;
- an electronic component;
- a glossy leaf.
A small light can appear as a bright white reflection.
The solution is often diffusion.
Place translucent material between the light and the subject and the apparent size of the light source increases.
The result is softer illumination and gentler reflections.
At macro scale, the diffuser can itself be tiny.
I sometimes find that the lighting accessories surrounding the subject begin to look like a full photographic studio that has somehow been shrunk to doll's-house proportions.
Specular Reflection: The Bright Spot That Will Not Go Away
One of the great challenges in macro photography is the specular highlight.
You move the camera.
There it is.
You move the light.
There it is again.
You add another light.
Now there are two of them.
The problem is caused by reflection geometry.
For a smooth surface:
angle of incidence = angle of reflection
So rather than merely reducing the power of the light, it is often better to change its position.
This is another reason adjustable lighting systems are so useful for macro work.
Very small adjustments can move the reflection away from an important part of the subject.
What the Adaptalux System Gives Me
For much of my own close-up work, I use the Adaptalux system.
The great advantage for me is not simply that it provides illumination.
It provides positionable illumination at the right scale.
When the subject is only a few millimetres or centimetres across, conventional studio lamps can become rather clumsy.
I may want one light extremely close to the left of the subject, another behind it and perhaps another directed almost horizontally across the surface.
That becomes much easier when the lighting equipment itself is designed for close-up work.
It also encourages experimentation.
Rather than simply asking:
"Is there enough light?"
I can ask:
"What happens if this light moves slightly lower?"
"Can I reveal the surface texture?"
"Can I illuminate just the edge?"
"Can I make the background disappear?"
"Can I see through the specimen rather than merely illuminate it?"
Those questions lead to much more interesting photographs.
A Simple Three-Light Macro Arrangement
A useful starting arrangement is surprisingly conventional.
Imagine the camera looking horizontally towards a small object.
Light 1 — Main light
Place it about 45 degrees to one side and slightly above the subject.
This provides the main modelling.
Light 2 — Fill
Place a weaker light on the opposite side.
Adjust it until the darkest shadows contain some visible detail.
Light 3 — Backlight
Position it behind the subject, ideally slightly off-axis so that it does not shine directly into the lens.
This creates separation and may reveal translucent or fine structures.
From there, experiment.
There is no reason the arrangement has to stay symmetrical.
In fact, some of the most interesting lighting comes from deliberately making it asymmetrical.
Practical Example 1: Photographing a Coin
A coin is an excellent way to practise macro lighting.
Try photographing it with the light directly beside the camera.
The details will probably look rather flat.
Now move the light until it is almost parallel with the coin's surface.
Suddenly the tiny raised features cast shadows.
Lettering becomes much more prominent.
Surface scratches may appear that were previously invisible.
The difference has nothing to do with changing the camera or lens.
It is entirely lighting.
This is one of the simplest demonstrations of why side lighting is so valuable.
Practical Example 2: Photographing a Crystal
Crystals provide a very different lighting problem.
Their surfaces can reflect, refract and sometimes transmit light.
Instead of trying to remove every reflection, it is often worth using them creatively.
Try:
- a main light from above;
- a second light from behind;
- a dark background.
Rotate either the crystal or the lights by very small amounts.
Different faces may suddenly illuminate.
This is a perfect example of macro photography being experimental.
A few degrees can completely transform the image.
Practical Example 3: Leaves and Flowers
Plants provide almost limitless macro subjects.
Start with normal front or side lighting.
Then place a light behind the leaf.
The photograph immediately becomes more scientific.
You may begin to see:
- vein patterns;
- differences in tissue thickness;
- surface hairs;
- damaged areas;
- pigmentation differences.
Then add a weaker front light.
Now we have both transmitted and reflected illumination.
This can produce some remarkably detailed photographs.
Practical Example 4: Insects and Other Organisms
Living subjects create additional challenges.
They move.
They may react to heat.
They may react to bright illumination.
And they usually refuse to sit exactly where the photographer wants them.
For living organisms I therefore try to work efficiently and avoid unnecessarily intense or prolonged lighting.
A slightly diffused main light combined with gentle fill can often produce a much more natural-looking result than harsh direct illumination.
Backlighting can also be particularly effective for wings, legs, antennae and fine hairs.
But with living specimens the welfare of the organism must come before obtaining the photograph.
Macro Lighting for Science
This is where macro photography becomes especially interesting to me.
We do a considerable amount of close-up imaging as part of science demonstrations and experiments.
The objective is not always artistic photography.
Sometimes the camera is effectively another scientific instrument.
We might want to record:
- the structure of a specimen;
- a chemical crystal;
- the behaviour of a small organism;
- corrosion;
- an electronic component;
- a fracture;
- the growth of a plant;
- the surface of a material;
- a reaction taking place on a small scale.
Lighting determines what information the camera actually records.
And changing the illumination can reveal entirely different characteristics of the same object.
That is a useful scientific lesson in itself.
What we see depends partly on how we choose to illuminate it.
Dark-Field-Like Effects
Another interesting experiment is to illuminate the subject from the side while keeping direct light away from the camera.
Tiny particles, fibres and transparent objects may then appear bright against a dark background.
It is not necessarily true laboratory dark-field microscopy, but the visual principle is similar.
Instead of flooding everything with light, we deliberately arrange the illumination so that much of the light reaching the camera has interacted with the subject.
This can produce spectacular photographs of:
- glass;
- fibres;
- tiny droplets;
- transparent plastics;
- crystals.
The Background Matters Too
It is very easy to become so interested in the macro subject that the background is forgotten.
But at these scales even the background is part of the lighting arrangement.
A black background can make rim lighting dramatic.
White can create a clean scientific appearance.
Coloured backgrounds can complement flowers, minerals or manufactured objects.
A background several centimetres behind the subject may blur completely because macro photography often produces extremely shallow depth of field.
That allows surprisingly simple materials to become convincing photographic backgrounds.
A piece of card can effectively become an infinity backdrop.
The Constant Battle With Depth of Field
Lighting also helps solve another fundamental macro problem.
Depth of field becomes extremely shallow at high magnification.
We often compensate by using a smaller aperture.
But a smaller aperture means less light reaches the sensor.
We then have several possibilities:
- increase the exposure time;
- increase ISO;
- add more light;
- combine several images using focus stacking.
For static scientific subjects, longer exposures may be perfectly acceptable.
For a moving organism they usually are not.
Good macro lighting therefore does more than make the subject attractive.
It gives the camera enough light to use the aperture and shutter speed we need.
Lighting Macro Video
Video creates another challenge.
With still photography I might happily use a long exposure.
Video cannot normally depend on that approach.
If I want to record a moving organism or a scientific process, I need continuous lighting sufficient to maintain sensible exposure settings.
This makes control even more important.
Lighting that looks acceptable to the eye may produce:
- excessive highlights;
- deep shadows;
- distracting reflections;
- insufficient exposure;
- very high ISO noise.
The solution is again to build the illumination systematically.
Main light first.
Fill second.
Backlight if useful.
Then adjust.
Try Turning Lights Off
One of the most useful lessons I have learned in photography is that adding another light is not always the answer.
Sometimes removing one is.
If a macro subject looks confused, I will often turn all but one light off.
Then I rebuild the image.
What is the main light doing?
What does the second light contribute?
Does the third light actually improve anything?
This is particularly valuable in macro photography because multiple reflections can quickly make an image visually complicated.
Every light should have a purpose.
A Useful Macro-Lighting Exercise
Choose a single small object.
A screw, coin, leaf, flower, shell or electronic component will do.
Put the camera on a tripod and do not move it.
Now take photographs using:
- front lighting;
- side lighting;
- lighting from above;
- lighting from below;
- backlighting;
- main light plus fill;
- main light plus reflector;
- main, fill and backlight;
- hard light;
- diffused light.
The object has not changed.
The camera has not changed.
The lens has not changed.
Yet you may end up with ten photographs that look remarkably different.
That is one of the best ways to understand lighting.
Macro Photography Is Really the Study of Light
It is easy to become fascinated by equipment.
Macro lenses.
Extension tubes.
Focus rails.
Tripods.
High-resolution cameras.
Focus stacking.
All of them have their place.
But none of them can rescue lighting that fails to reveal the subject.
What I increasingly enjoy about macro work is that it makes lighting principles exceptionally obvious.
You can see exactly what happens when a light moves.
You can watch a texture appear.
You can see a reflection travel across a surface.
You can illuminate one side of something only millimetres across while leaving the other side almost completely dark.
Photography becomes a practical experiment in optics.
And that is probably why macro photography fits so naturally with much of the scientific work we do.
Conclusion: A Complete Studio in a Few Centimetres
Macro lighting is not really a different branch of photographic lighting.
It is conventional lighting compressed into a tiny space.
We still have:
main light + fill + backlight + diffusion + reflection + shadow
But because the subject is so small, the effects become exaggerated.
A light moved a centimetre can change the picture.
A piece of white card can become a major reflector.
A tiny diffuser can transform reflections.
Backlighting can reveal structures that front lighting completely hides.
That is why systems such as Adaptalux have become so useful in the type of photography I do. They allow me to construct a miniature lighting studio around a scientific specimen, organism or ordinary household object and then experiment.
And experimentation is really the key.
Macro photography encourages us to stop thinking of light merely as something that allows the camera to see.
Light determines what the camera sees.
Sometimes the difference between an ordinary close-up and a fascinating macro image is not a new camera, a more expensive lens or greater magnification.
It is simply moving the light.
By a centimetre.
