Melasti - Amed, Bali, Indonesia - 2019

Welcome to my first post in a series which I intend to continue for most of my photographs. For a short explanation on why it is the way it is, I wrote another blog post setting out a little “manifesto” on these posts. I hope it inspires you, and encourages you to care a little bit more about our beautiful planet.

The Story

I had first heard about these tiny “sheep nudibranchs” from another diving photographer who was into macro photography. When I first saw a photo of one I nearly laughed. This little goofy thing can’t be real!

At the time I took this photo, I was working at a dive center on Bali, Indonesia with my wife. We would often go “fun diving” on our days off. While teaching and guiding I almost never bring my camera with me to ensure my students and divers are my only focus. I truly relish in the fun dives as a chance to fully relax and enjoy the zen of diving in tranquility.

One evening, we decided to dive at an easy and shallow dive site at the end of our street - Melasti. The site itself is a unassuming, and mostly sand. But there are patches of algae and rocks where life has taken hold. This is known as a “muck” dive: most of the creatures are small, very-well camouflaged, and require patience to find.

The dive started as normal, with my wife and I pointing out various shrimp, fish, eels, or an occasional cephalopod (think octopus, squid, or cuttlefish). About halfway through the dive, I wandered out to the deeper and more barren sandy patch before the site’s decent to deeper water. Here I searched patches of small green leaves for any signs of these elusive sea slugs. When I finally found one, I was so excited to show my wife.

Communicating underwater is typically done with hand signals. The hand signal for a nudibranch is showing the number 2 and bending the fingers forward like floppy rabbit ears. I gave her the hand signal and pointed to where I’d seen it. At first she couldn’t find it since it was so tiny. And since we hadn’t agreed upon a hand signal to describe this specific nudibranch, the only thing I could think of was to bleat like a sheep into my regulator.

“BAAA-AH-AH-AH-AH!”

Many laughs were had.

The Subject

Costasiella kuroshimae. This one was tiny: about the size of the tip of a ballpoint pen. The green parts in its body are actually chloroplasts (think photosynthesis from your intro biology class) taken from the leaf it feeds on. Some scientists affectionately call these kleptoplasts. These stored chloroplasts actually allow the slug to absorb nutrients created by photosynthetic action. Thus, it is a solar-powered sea slug.

The effect of a warming climate on little nudibranchs like this one is still largely unknown. Other molluscs have been struggling with warming and acidifying waters as bacterial infections increase and struggling to maintain strong shells. Either way, I hope to continue sharing some of the beautiful creatures that live just under the surface to encourage others to take up the fight in protecting our oceans.

The Environment

Each underwater photo comes with it’s own challenges. This dive site is particular in that it is very shallow (3-6m), and right on the coast. There are days when the water is still and crystal clear. But most days there are waves. And while we are far enough from the shore to not be affected directly by the waves, there is still a surge. This surge will pull you back and forth, to and fro, perpendicular to the shore. And on top of that, few sites on Bali, or in Indonesia for that matter, are protected from constant current. This site normally had a mild to moderate current. This is the constant water movement along, or parallel to, the shore.

These two factors mean the water is often turbulent, turbid, and frustrating for a photographer. All of this movement means the leaf on which the nudibranch was crawling, is in constant motion. To counteract this, I’ve seen underwater photographers steady themselves in all the wrong ways: Using “sticks” - plunging them deep into the sand, holding onto a rock or coral - often breaking or crushing an organism, or laying on the sea floor - disturbing or crushing anything in their path, fins everywhere.

These are bad habits that damage the environment. Furthermore none of those “techniques” are required to take a good photo. We must prioritize taking care of the environment over capturing a photo.

The trick is to have perfect buoyancy, good lighting, and great timing:

• When in perfect buoyancy, we move WITH the water, not against it. We are motionless. This allows us to take a clear, focused photo without touching anything.
• Lighting is also an important factor, especially when the water is dark and not enough natural sunlight penetrates to our subject. Good lighting allows us to use a smaller aperture, lower ISO, and faster shutter speed - All of which give us a better photo with greater depth of field, less noise, and an image void of motion blur.
• Timing is critical for creatures. Nudibranchs are a popular subject for underwater macro photographers since they generally move VERY slowly, and don’t scare easily. In this case, I had to wait patiently for the leaf to come to me. I set my lighting and focal distance based upon where the leaf would be after a following swell moved it back into position.

Remember that we are entering their home. We are the intruders. Let’s enjoy it, and leave no footprint of our presence.

The RAW shot

A very smart person once taught me that the better the photo going in, the better the photo coming out! The less we have to touch it the better!

Well I didn’t really accomplish that here. At first glance it’s quite obvious that the photo is underexposed. This is easily confirmed by looking at the histogram.

But before going further, let’s talk about how this photo was taken.

The Gear

My underwater camera is a SONY a6500. For now I’m still using the kit lens as it fits nicely inside a relatively small package and has a decent focal length of 16-50mm. Since changing lenses underwater is (sort of) impossible, I have been happy with this setup so far. In this photo I am using a macro accessory lens that takes this tiny, ball-point-pen-tip sized nudibranch to a size we can easily view. That doesn’t mean I got it right on the first try.

So why are the images so dark? Well a few reasons:

1. Avoid overexposing the subject - I find it easier to bring up details in slightly underexposed areas, where overexposed areas tend to lose data easier. Of course I prefer perfect exposure whenever possible…
2. Use a fast shutter speed - This is to reduce motion blur which we are especially susceptible to underwater. The camera is limited to 1/160 while using the flash, so I try to keep it >= 1/90 whenever possible.
3. Keep the ISO low - This is to reduce noise in dark areas. This type of macro photography tends to generate lots of black and dark areas, thus I like to keep my ISO < 320.
4. A small aperture - This gives me more depth of focus. Since these photos are taken in-motion, this helps if I “miss” the perfect focal point.

Because I shoot in raw format, even photos like this one have plenty of information to bring up the exposure and end up with a great image.

I also really liked the composition, position of the subject, and the “facial” expression it’s giving me. Most of my other shots did not really give a good view of the creature’s face, which I find important when taking photos of “alien” creatures that most people will not be able to identify in the first place!

The Edit

I don’t intend to walk through the ENTIRE process, but highlight a single step in more detail. Throughout my blog posts I hope to cover more and more of the steps to show a bit about how they all are important and what aspects I’m looking at while doing that edit.

Opening raw files directly into my preferred photo manipulation software (GIMP) is not possible. Thus we must use a program like Raw Therapee or Darktable. Both are honestly great, but I’ve gotten comfortable using Darktable.

For this photo the first thing I will do is fix the exposure:

However, I want to be careful how much I play with this setting. To be sure I don’t overexpose areas on the image, I will use Darktable’s “raw overexposed” and “clipping masks”. These will highlight in red/blue which areas are poorly exposed. I will often click them on to be sure I haven’t accidentally pushed a critical part of the image into a clipped/overexposed area.

This doesn’t only apply to the “exposure” filter. I also use this setting when dealing with other filters.

At this point I will make a few other minor tweaks like noise reduction (think about how ISO plays a role in this).

And at this point I will normally export to GIMP for the back scatter removal and fine tuning of colors, contrast, and sharpening. I generally finish with a final crop before exporting the image.

What I learned

This image was all about planning the shot. You could see from my above “misfires” that I had a number that weren’t quite right. Luckily my subject moved slowly and I was able to remain calm, maneuver into position, and patiently wait for the right moment. This isn’t always possible with some creatures that scare easily, but with nudibranchs, it’s usually best to be patient and plan the shot - get your ISO, aperture, and shutter speeds on target, get your flash positioned correctly and at the right intensity, and wait for the perfect moment.

I generally don’t “review” any of my photos underwater - it’s not a good use of my time there. But I will generally have a quick look at the image as it quickly passes through the viewfinder to see if it was under or overexposed. When the subject allows it, I will often take a few exposures, either bracketing, or stepping up/down a couple of times. The amount of information stored even in a dark image is incredible.

This article was also a nice exercise in exposure correction as I’m still learning my post-production software every time I jump in. Yes, I could easily use the “auto” functions, or jump into the AI world of A****’s tools. But I think that takes away from the joy of artistic creativity and causes us to lean too heavily on automation: thus degrading your own abilities.

Conclusion

When shooting underwater, we rarely have multiple opportunities to “reshoot” a subject. And if you’re traveling, you may never get a second chance at seeing a subject. This is why I find it critical to know your gear, know its capabilities, and be ready with the correct settings for the subject you want to photograph. And even if you don’t get the “perfect” shot, know that if you’re shooting in raw, there’s often a lot you can do to a photo in post-production to find a gem in the rough.

I hope you found this little write-up informative if nothing else, and I welcome your comments and suggestions in the section below. I am always trying to learn more and improve my skills.