Macro Photography Basics: Mastering Lighting, Settings & Strobe Techniques Underwater

Mike Bartick explains how to master the basics for great macro imagery

Photography by Mike Bartick

Developing an eye for macro is just as important as learning how to shoot them. Here a bright yellow damselfish is guarding and aerating her eggs. The whip coral has a reef behind it, so with a slight adjustment of angle, the scenario changes. Now with nothing behind the subject a black background is simple and effective in bringing out the details.

Shooting macro is a challenging approach to underwater photography where hunting for subjects is actually half the fun. Similar to a treasure hunt, the substrate has many hidden gems tucked away, waiting to be discovered.

Getting into macro mode is just as much of a mindset as it is a skillset of shooting. We need to develop our eye for finding scenarios that depict a world not often seen, then attempt to connect the viewer to the subject on a more-intimate level.

Instead of photographing a nervous fish, we might watch and observe to discover the fish is guarding a patch of nearby eggs, or the pair of colorful slugs are mating. Macro is all about going slow, being observant, looking small and finding big.

Unlike shooting wide angle, where a shooter might have minimal amounts of gear, macro shooting can become gear intensive very quickly. And while having good gear is important, possessing skill and knowledge is priceless.

Essential gear for mirrorless, compact or DSLR set-ups includes strobes (one or two), a focus light and – if you’re using a camera body with interchangeable lenses – amacro lens capable of doing 1:1. Keep it simple and don’t task load, the extra gear can wait.

Becoming a better macro photographer requires building a solid foundation on the fundamentals of lighting – how light plays on a given subject and the techniques in how to control and manipulate that light.

The best way to do this is by going out often with a skill shot in mind and working on it. In the meantime, a few pointers will also help to shorten the learning curve.

Basic Jump setting (ISO 100, ƒ14, 1/250) with nothing behind the subject results in a black background. The shutter speed and ISO have tamed the ambient light and the strobe flash creates natural color and sharpness. Here I’ve adjusted my aperture to ƒ18 to help keep the background black.

Using the same subject two create an image in multiple ways is a great way to learn your settings quickly. Park yourself Infront of a subject and start at your jump setting.

Open your aperture from ƒ14 to ƒ11, ƒ9 and so on. The reverse directions from ƒ14 and higher. Do the same with shutter speeds. Then use only your ISO.

Slowing the shutter to 1/200 and opening the aperture to ƒ13, allows for the ambient light to enter the frame from behind. It’s always nice to see the blues but even better if you’re in a green water location like Monterey, Calif.

This technique is generally used for wide angle but it’s a great step towards learning how to control ambient light.

A lovely purple Hypseledoris nudibranch shot with slightly different settings and camera angle, results in two dramatically different results.

Basic skill shots

To achieve a black background, it’s all about shot selection. Look for a subject that is perched on something and has nothing behind it. Use a fast shutter speed and a low ISO and a moderately narrow aperture to start.

When trying to achieve a black background, you will also want to avoid adding light to the background as much as possible. Inward lighting is a great trick and can be achieved with a single or dual strobes. Simply point your strobe heads inward towards your lens port. Right strobe pointing across to the 8 o’clock position and the left strobe across to the 4 o’clock position.

Think of a ‘lazy X’. Avoid aiming the strobes directly across the lens port at each other to avoid backscatter and be sure you are within eight to ten inches of your subject. Your housing will block 80 percent of the light, illuminating only the immediate area in front of your lens port.

ISO 100 | ƒ-14-ƒ18 | 1/250

To achieve a blue background, again it’s all about shot selection. Using the same scenario as above, including inward strobe positions. Look for a subject that is perched or has nothing behind it. Except now, slow your shutter speed down and begin to open your aperture.

Be sure to aim up into the bright water column, but avoid aiming directly at the sun. Creating a blue background takes a little tinkering with your shutter speed and aperture, but your ISO can remain constant if it’s a sunny day.

ISO 320 | ƒ, 11-ƒ,14 | 1/60

Shooting macro on the sand is actually harder than it looks. The object is to keep your subject from blending in with the substrate. Shoot from a low angle with strong eye contact, use a moderately open aperture and keep your strobes at 10 o’clock and 2 o’clock, facing forward and off the sand.

Become comfortable using your ISO, Shutter Speed and Aperture. These three main tools, known as the ‘three pillars’, are how you fine tune light to create your photos, regardless of the style of photos you are trying to shoot. When practiced, this is also referred to as the ‘exposure triangle’.

However, with macro, our triangle is a bit obtuse as we are not trying to blend our strobe flash with ambient light as we would when shooting wide-angle images.

While macro is also about controlling the light, we often time want to under expose the background to eliminate light all together while maintaining proper exposure in the foreground.

Mastering the three pillars

The three pillars are modular. Ultimately, they all have an effect on light but in a different way. To understand how each of them work independently, begin by setting your ISO and shutter speeds to the jump setting below and concentrate on using just your aperture. Then move to using only your shutter speed, and finally ISO.

Basic macro jump setting:

ISO 100 (ƒ,14) | Shutter speed 1/250 | Aperture ƒ,14-ƒ18 Strobe power 75%

ISO -Controls any/all light exposed to the sensor plane. Higher ISO increases light sensitivity, lower ISO reduces light sensitivity. ISO can be used to maintain exposures throughout your entire aperture range and shutter speed. ISO is a function of the camera body that controls light after it has passed through the lens.

Shutter speed -Controls the speed at which your shutter opens and closes, exposing your sensor to light at timed intervals. The longer the shutter remains open means more light can travel through the lens to the sensor plane. This is used primarily to control ambient light when shooting macro underwater.

Aperture -Is the size of the opening that the light moves through on its way to the sensor plane. Aperture size also plays a key role in depth of field. However, the aperture is better used to fine tune the appearance in a macro image rather than altering exposure values overall.

Using an open aperture (small number) will result in blurred backgrounds where narrow apertures (larger numbers) results in a greater depth, clarity and the need for more light.

Assuming your strobe power is 75%, without changing the power of the strobe flash, you can easily adjust your settings to compensate for a brighter or darker frame, or to maintain your exposure at any setting. Use your ISO and aperture in tandem. As you increase your aperture, increase your ISO and vice versa.

The way apertures are described is confusing and counterintuitive. Apertures are described in stops, or ƒ-stops. I like to keep this simple and categorize ƒ-stops into three main groups. Remember, we are shooting macro underwater, so we can streamline the process.

Wide apertures – ƒ2.8- ƒ8

Very limited depth of field, a lot of light, extremely compressed appearance.

Medium wide apertures – ƒ9-ƒ13

 will provide moderate depth of field and bokeh are both present. Bright macro images are made in this range that effectively separate your subject from the background.

Medium apertures – ƒ14-20

Natural depth of field, with light that is easy to manage.

Small apertures – ƒ20 and smaller

Increases of your depth of field, you will need more light, compensate by increasing our ISO to maintain exposures or risk underexposing the foreground. The widest aperture points have the ƒ-stops with the smallest numbers. As the aperture is divided down, the number increases.

In general, if your lens is a 2.8 lens and you’re shooting at ƒ8, then this simply means, the original aperture has been divided eight times. Each stop of light is a division of itself, resulting in less light. The higher the ƒ-stop, the smaller the aperture, which results in the need for more light.

The upside to shooting at higher apertures is a greater depth of field. Opening your aperture ultimately results in an influx of light, softer backgrounds and in some cases a distortion of colors.

*For shooting basic macro on the sand, I prefer to shoot at medium wide to moderate aperture settings between ƒ, 11 and ƒ,18 with close attention to my strobe positions.

This aperture range helps to compress backgrounds naturally and to isolate our subject from other distractions while providing natural depth of field, similar to our own vision.

Strobe positioning

Strobe positions are also important but try not to overthink it. Keep your strobes up and off the sand, keep it simple and keep your mind on using your ISO and aperture.

Two Strobes – 10 o’clock and 2 o’clock position
Single Strobe – 12 o’clock position

Either position will help to control your shadow and keep it under your subject.

Contrast can often be a double-edged sword when shooting macro on a muck dive, particularly when shooting on the sand. I always recommend using diffusers to ‘soften’ the contrast between the high and low tones.

Sand is comprised of many things including white reflective shells, crushed urchin spines and other particulates. Using diffusers will help to blend all the various tones to a more even light value.

Bringing your mind around from the editing portion of shooting photos to conceptualizing an image is how a diver with a camera begins to round the corner to becoming a photographer.

Using the skills above will help to build a solid foundation to grow and soon, your portfolio will begin to take on a different shape and style. Get out often and remember to always have fun!

Mating nudibranchs – ƒ18 -Slugs were made for macro photographers. They are slow, colorful and are always up to something.

Here we have two mating Thecacera nudibranchs. Getting low with nothing behind the subject and a slightly smaller aperture is all that is needed to capture the beauty of these little beasts.

FAQ: Macro Photography Basics

Q: What is the ‘jump setting’ for shooting underwater macro?

A: A common starting point is ISO 100, ƒ14-ƒ18, and 1/250 shutter speed, with strobe power at about 75%. From here, you can adjust aperture, shutter speed, or ISO to achieve different effects.

Q: How do you create a black background in underwater macro?

A: Position the subject with nothing behind it, use a fast shutter speed, low ISO, and narrow aperture. Strobe positioning inward toward the lens port also helps eliminate background light.

Q: How do you create a blue background in macro shots?

A: Use a slower shutter speed and open the aperture while aiming slightly upward into the water column (but not directly at the sun). This allows ambient light into the frame while the subject remains lit by strobes.

Q: What is the best way to shoot macro on sandy bottoms?

A: Use a low shooting angle, aim for strong eye contact with the subject, and position strobes at 10 o’clock and 2 o’clock to avoid harsh shadows or backscatter from the sand.

Q: What are the ‘three pillars’ of underwater macro photography?

A: ISO, shutter speed, and aperture form the exposure triangle. Each affects light differently: ISO adjusts sensitivity, shutter speed controls ambient light, and aperture influences depth of field and subject-background separation.

Q: Do I need special gear for macro photography?

A: Essential gear includes at least one strobe (two is better), a focus light, and a macro lens (for interchangeable lens cameras). Extra accessories like diopters can wait until you’ve mastered the basics.