- Talia Greis
Intro to UW Photography
Updated: Oct 13, 2022
Learning the essentials to shooting manual in an underwater environment.

Photo by Talia Greis
Mastering underwater photography is possibly the most challenging discipline of the arts. In a sense, it is taking a system of imperfection, and using what we have in order to achieve "the shot".
Now add the elements of darkness, buoyancy, and the ever changing unpredictability of the ocean and its inhabitants.
It’s a wonder we haven’t thrown in the towel!
“The Smaller the number, the larger the F-stop”
So … If you're taking the plunge, and considering the switch to manual photography (whether it be through an upgrade in equipment, or a change in settings to take full control of your vision), it’s important to understand the basics.
Let’s begin.
The Exposure Triangle
Herein lies the answer to every question you could possibly have. I tried to wrap my head around this confusing triage of trouble over and over again, and eventually the penny dropped, and it all made sense.

ISO, Aperture, and Shutter Speed. The three musketeers of our world. These three features are the embodiment of light, and therefore, understanding these three influences will directly affect how we achieve the outcome we desire.
Aperture (Athos)
Think of aperture as the human iris of your camera. Like an iris, the the brighter your surroundings, the smaller it becomes, and likewise, the darker your surroundings, the larger is gets. This is exactly how aperture works.

Example of Small Aperture F20 (Left) Example of Large Aperture 2.8 (Right)
Things to know:
1. The smaller the number, the larger the aperture (just in case this wasn’t confusing enough)
- E.g. F2.8 is a large F-stop, F20 is a small F-stop -
2. The Larger the F-stop, the greater your depth of field (DOF)
- This is the artistic technique that makes the foreground sharp, and the background blurry.

3. The smaller the F-stop the darker your surroundings, and the larger the aperture the more light is at your disposal.
- E.g. F20 will make for a darker picture than F5 -
4. Wide angle shots are more forgiving with DOF than macro, with regards to how much "blur" you will bring into the shot.
5. A smaller aperture will produce richer tones
Shutter Speed (Porthos)
In my opinion, probably the most important of the three. Simply put, Shutter speed (SS) is how long the lens stays open, and how much light is let through the iris and onto the sensor. In a perfect world, we would be able to control the shutter speed without compromise … but photography is anything but perfect. So … this being said;
Let's say you’ve chosen to dive on an overcast day, early in the morning, at a site that is plagued with shocker visibility. An ever-to-common problem we face in Sydney waters!
But with a stroke of luck, you’re greeted with an incredibly playful seal who wants nothing more than to hang around for a decent photoshoot.
Things to know:
1. Seals are fast! The slower the shutter speed, the more you will capture their movement, and therefore not achieve a crisp photo.
2. Most strobes (if using) have a limit to how fast you can set your SS for them to fire. With my Nikon D850, and Inon Z330 strobes, the limit is 1/250
“Shutter speed (SS) is how long the lens stays open, and how much light is let through the iris and onto the sensor."
In this particular instance, you have one of two choices.
a) Forget the strobes, pump the shutter speed up to 1/500 and use natural light.
b) Use your strobes, and deal with the limitation it has. REMEMBER! Strobe light will freeze action to a degree. So if your strobes are hitting the subject with enough intensity and in the correct manner, you will freeze your subject. This technique is actually quite rewarding, as it creates a sense of movement in the photo.

ISO (Aramis)
ISO is the last piece of the puzzle, and in my opinion, the last setting you should tamper with. It’s the “pick-me-up” you may need, because you’ve hit a wall with your settings.
For example, let’s revert back to our playful seal;
You’ve decided to shoot with strobes (SS at 1/250) and because it’s it’s a wide angle shot, you’re going to open up your F-stop all the way to 2.8. However, because it’s a dark gloomy day with minimal light, the shot is still underexposed.
This is where ISO creeps in. But again, photography is impossible in nature, and won’t submit without compromise. So yes, you can pump your ISO up to 500, 600, 700 … and it will certainly give you the light you need. BUT, it will also give you “grain”, which is comparable to the unrefined, pixelated imagery you would typically get with your old black and white films.
“Photography is impossible in nature, and won’t submit without compromise".
Simply put: High ISO = Citizen Cane

Photo by Talia Greis
Low ISO = Avatar

Photo by Talia Greis
Things to know:
1. ISO has a direct relationship with your camera’s sensor.
- The Larger the sensor, the more forgiving the grain -
(*More information on Camera sensors to come in our upcoming blog*)
- A large sensor may only start to give grain at 4000, whereas a smaller sensor will likely start at 200 -
2. High end cameras will generally have a larger sensor
The End Game
Nothing in life is without compromise, and far from perfect ... this is especially true with underwater photography. Somehow, we need to take what we have, and churn the static elements of the photographic world into miracles. There will be numerous ups and downs, and endless swear sessions that require a plug in your mouth (or in this case a regulator or snorkel). BUT, when you nail the shot ... there are no words needed.
On that note, the only thing left to do is to gear up, and get going! Practice is paramount.
Just in case you wanted some directional pointers, here are some underwater examples of specific critters and my go-to settings. Bear in mind, these are by no means set in stone. But the correct decision for the moment at hand.

Photo by Talia Greis
Macro subjects this size can only be captured in whole by using a versatile lens like the 60mm macro. Because we are generally trying to capture detail when it comes to macro, a fast shutter speed is preferable, as well as a small - mid aperture and a low ISO.
Nikon D850 with a 60mm lens and dual Z330 strobes.
1/200, F16, ISO 160

Photo by Talia Greis
Shooting wide angle requires the ability to not only consider the subject at hand, but the environment as a whole. Framing is key. Consider elements like positioning of the sun, additional marine animals, and how the subject is framed.
Nikon D850 with a 16-35mm lens and dual Z330 strobes.
1/160, F10, ISO 80

Photo by Talia Greis
Capturing motion in a creature can be achieved successfully by slowing the shutter speed right down, and ensuring your strobes hit the subject correctly. In this instance, we have a shark performing a fast sonic crack with a relatively slow shutter speed. Note the blur motion around the edges of the shark, creating a sense of movement in the shot.
Nikon D850 with a 8-15mm lens and dual Z330 strobes.
1/80, F13, ISO 200

Photo by Talia Greis
Smaller subjects are more likely to fade out with regards to Depth of Field. Normally F16 is considered a mid-range aperture, however, when you're shooting critters like Nudibranchs or slugs, you'll want to close your F-stop as much as possible if you don't want the "blur feature".
Nikon D850 with a 8-15mm lens and dual Z330 strobes.
1/200, F16, ISO 100
Stay tuned for our upcoming blog on Equipment Selection.
Good luck, and god speed!