top of page
  • Writer's pictureSam H

How to Shoot Sea Slugs & Nudibranchs Part 2

In part one of this series of articles, we looked at several aspects of mastering nudibranch and sea slug photography. We covered different things, from composition, learning about nudibranchs and how to spot them, to managing your expectations and how to practice your photography.


Underwater photo of a nudibranch

So far, that was only scratching the surface of this deep and varied topic. There is much more to take in before you grab your mask, fins, and underwater iPhone Case and jump in to start snapping away. From things, you should keep an eye on when diving into understanding various lenses and camera settings. Read on to find out how to fine-tune your nudibranch and sea slug photography.

Get a Macro Lens

If you are going to get into nudibranch and sea slug photography, there is one accessory that you need to invest in above all others a Macro lens. While some creatures like the famous Spanish Dancer are very large nudibranchs ranging from 25cm/10 inch to 40cm/16inch, it is the outlier. Although a fabulous one at that, especially if you are lucky enough to see one doing its thing and dancing!



The stunning Shaun the sheep, discussed in the first article, is at the opposite extreme of a Spanish Dancer. You can forget about taking a picture of one of these guys if you don’t have a macro lens. Typically, they are 2-3mm long, around 1/16 of an inch. There is no way to capture their stunning glory without a macro lens.



Actually, speaking from personal experience, it is almost impossible to find a Shaun the Sheep without a macro lens. They are so small that you can not see them properly with the naked eye. All you see is a small green blog on the seagrass or algae. You then need to look through your camera lens to determine whether you are looking at Shaun or a tiny piece of fluff!

Even at the mid-size range, a lens has its role to play. While it is true, you don’t need a macro lens to shoot a Spanish Dancer, and the vast majority of nudibranchs are in the 5cm/2 inch range and smaller. You will still need a macro lens to produce a great picture of these critters. If you wanted to shoot an image of the whole creature lit and in focus, you could pull it off without a lens. However, the minute you want to draw attention to the rhinophores and have them in focus, you will need a macro lens because they are tiny. So ultimately, even if you are trying to shoot a mid-sized nudibranch to get excellent images with great composition and effects, you will definitely need a macro lens.

Pay Very Careful Attention to Your Feet

When it comes to shooting nudibranchs you need to be very aware of your fins. Otherwise, you will have some unhappy fellow photographers, possibly nudibranchs and sea slugs. More often than not, when taking images of Nudibranchs and Sea Slugs, you tend to be very close to the sea floor or on the actual sea floor.

In these circumstances, be very careful where your fins touch the sand. Make sure you are touching nothing but pure sand. If there are any small coral outcroppings, make sure to give them a wide berth with your feet.


Woman taking photos underwater of colorful fish and sea slugs using a ProShot Dive case and macro lens

While it may seem common sense to avoid damaging nature, your fins can devastate tiny, delicate creatures. A small coral outcropping no more than a couple of feet wide could be home to multiple tiny species of sea slugs and nudibranchs. Resting your fins on it even lightly will not endear you to the inhabitants or fellow photographers trying to find their next target. If you are in doubt, stay in a hover and shoot from that position without touching the bottom.

Learn Your Camera Settings & Lighting

The biggest thing you can do to improve your nudibranch and sea slug photography, and your photography in general, is to fully understand your camera settings and, more importantly, how they affect each other.

Understanding your shutter, speed, F stops (aperture), ISO, and how they interact with each other and with your lighting sources is key to creating stunning images. Bear in mind the actual dynamics of the relationship vary between one rig and another. So not only do you need to understand them individually, but also what they do in your rig.



Take, for instance, altering your shutter speed at the same aperture; what does it do? If your shutter speed is too fast, your image will be very dark since not enough light has hit the sensor. If it is too slow or your aperture is too wide, your image can be overexposed and washed out. Get your shutter speed just right and produce a crisp, sharp, in-focus image. If your lighting is spot on, it will have no backscatter, and the colors will pop.

A small tweak on the shutter speed and aperture can create a very different effect that is famous in nudibranch photography. Get your settings right and shoot at the right angle where the creature has a predominantly blue background, and you can turn that background black. The settings allow enough light in to have the animal sharp and in focus but no more. But the background is totally black, even during the middle of the day. These are some of the most sought-after and stunning images in the world of nudibranch and sea slug photography.



Depending on many factors, each camera will have its own idiosyncrasies. Your best option is to study, then head into the water and practice. You can also take an underwater notebook to note the various key setting of your images. This lets you review the image on a laptop with a clear indication of the settings, which in turn gives you a better understanding of how everything works together.

Master Your Depth of Field

Understanding depth of field and how it relates to both your camera setting and composition is key to producing excellent Nudibranch and sea slug images. You can think of the depth of field as where do I want my focus to be. Do I want to have the entire picture in focus or just a portion? What type of image will both produce? What aspect of the creature do I want to empathize the most? That is what you want to be in focus.



Jumping a little to composition, what really speaks to us in images is the face, whether it be a human or an animal. One of the most famous pictures of the last century is the Afghan girl (Sharbat Gula), taken in 1984 by Steve McCurry. Depth of field plays a key role in the image. Her face and eyes are all you can make out everything behind her is a green blur that does not matter.

The same understanding of depth of field applies to wildlife photography regardless of size. Take, for instance, the following image of a nudibranch. The face is focused, and the rest of the body is a blurry orange and black. This focus and blurriness draw your eyes toward the face of the creature to observe what it is doing.


Underwater photo taken with a macro lens of an orange nudibranch

The depth of field does not have to go front to back. For instance, consider the next image; the depth of field only captures the tiny serrations of one of the Rhinophores. The rest of the body, even closer to the camera, is slightly out of focus. Bear in mind in terms of composition; this is not an ideal image. The camera position is not perfect, and as a result, the image is a little awkward.


Underwater photo of a nudibranch taken with a ProShot Dive case

Keep in mind depth of field does not only apply to nudibranchs and sea slugs. Take, for instance, the gentle dugong or manatee. These animals are larger than nudibranchs by a factor of millions. Yet you can still use depth of field and composition principles to produce stunning images. Take the following award-winning image of a dugong having lunch in the Red Sea.


underwater photo of Dugong eating lunch
Dugong eating lunch Image Courtesy of Laura Dinraths

The face is sharp and in focus, and you can almost see the creature savoring every mouthful of seagrass. As your eyes move back from the head, the focus disappears a little, although not too much. This reduction pulls your eyes back to the photo's important area, the face!

Final Thoughts

Nudibranchs and sea slugs are simply amazing photo subjects. Their variety and diversity are incredible. In fact, there are over 3,000 species stretching from pole to pole. That is why some underwater photographers are total specialists. They only shoot nudibranchs and sea slugs. They dive with multiple cameras pre-set up for different situations.

More often than not, these photographers will ignore everything else as they chase the ultimate nudibranch pick. What makes this even more interesting is that you can always experience something different. Whether it be a different environment, unusual lighting, or a new species you have not encountered. Before. Taking images of nudibranchs and sea slugs will challenge you, but it is ultimately one of the most rewarding activities you can undertake with a camera underwater.




Recent Posts

See All
Marine-Life Underwater Photography
bottom of page