This article is an attempt at sharing some of what I learned while shooting video on a couple of pelagic black water dives in Kona, Hawai’i. Before going on the dive, I found several great articles about pelagic black water photography. While similar, video and photos are certainly different in their own rights. Not to diminish the amazing work of underwater photographers, but video poses unique challenges that photography does not. For these dives, I was shooting on a Sony a7S II with Ikelite housing and two Light & Motion Sola 2000 video lights.
If you’re new to pelagic black water diving, take a look at Part 1 where I share my thoughts from my first pelagic black water dive.
Pelagic black water diving is not for the novice underwater videographer. Without any visual references, tasks that may normally be second nature for an experienced diver must be constantly on the conscious mind. Add a video camera to the mix and the task loading easily becomes too much. However, with a little preparation, you can set yourself up to capture some amazing video on a world class dive.
Master your buoyancy you must
As Yoda is a master of The Force, you must be a master of your buoyancy. The only visual references you have on this dive are the drop lines and dive buddies around you. While you could capture a really nice shot with a pelagic creature in the foreground and your dive buddy in the background, most of your attention is going to be in the opposite direction, looking straight into the black abyss. If your camera housing does not have a built-in depth gauge, I highly recommend rigging your dive computer or SPG so that it can hook onto your housing for quick and easy reference. As a bonus, clipping your console style gauge or computer to your housing provides a tether to your camera should you lose grip for any reason. Pay close attention to your ears as they will tell you if you’re ascending, descending, or holding steady at depth. Your buoyancy skills should be such that you can hang out anywhere in the water column in a horizontal position, adjusting your depth using nothing more than breath control.
There are several reasons for this. Although the boat is drifting with the current, you won’t be moving at the same speed as the water. This creates the effect of a slight steady current underwater that will carry you through the plankton soup containing all the alien life forms you set out to capture on video. Putting yourself into, and remaining in, a horizontal position in the water column reduces drag and will allow you to easily cruise into the current, then drift with a subject of interest. An upright position will make this all but impossible. Once you find a subject to focus on, it likely will not remain at a constant depth. You can either hang out at an arbitrary depth, letting your subject pass on by, or you can move with it through the water column, thereby extending the amount of time you have to capture some amazing video. Being able to adjust your depth solely with breath control will allow you to keep both hands on the camera, resulting in a nice steady shot. If you continually reach for your power inflator or dump valve, you add lots of fumbles and bobbles to your footage that cannot be smoothed out with any stabilization plugin or software.
Speaking of stabilization, those nice buttery smooth shots you might see on National Geographic take way more practice than you will be able to gather in even a week of diving. There are several software options for post-production that will help you get this look, but you’ll need to be sure to set yourself up for success with the right settings in camera.
The first step to successfully stabilizing footage in post is to eliminate motion blur. The Sony a7S II has a 5-axis stabilized image sensor that works wonders! Many current camera models – whether point and shoot, DSLR, or prosumer video cameras – offer features for image stabilization. Be sure to turn these features on, but also understand that optical stabilization works best. Digital stabilization will smooth out the image, but will not help to reduce motion blur. With my a7S II, I shot with a shutter speed set at three times my focal length. If using a camera without image stabilization, or one that doesn’t provide optical stabilization on five axes, you’ll want to increase your shutter speed even further. The general rule of thumb in video is to set your shutter at twice your frame rate, so shooting at 24p would mean a shutter of 1/48. This is simply too slow to eliminate the motion blur you get from bobbing around in the water tracking an object a couple inches off your lens that is moving independently from yourself. If you try to stabilize footage that has too much motion blur, the result may be smooth, but it will look like the focus is constantly searching.
If your camera is 4K capable, shoot in 4K! Yes, this may require investing in a larger memory card so you don’t run out of space half way through the dive, but it’s well worth the investment. Shoot your subjects with a little more room around the edges than you normally would. Instead of editing in a 4K resolution project, edit the 4K footage into a 1920×1080 project. This will provide some space for the post production stabilization to occur, and will allow you to crop in as necessary without losing any quality. By scaling down the 4K footage to HD resolution, this will also reduce the apparentness of any remaining motion blur and the digital noise created by shooting in a higher ISO (gain) setting.
Lens choice plays a major role in stabilization. Knowing that many species you will encounter on this dive are quite small makes rolling up to the boat with a 100mm macro lens very tempting indeed. If you’re shooting stills, this is a great choice! With video, on the other hand, you will end up with footage so shaky you may get sea sick sitting at your computer. The longer the focal length of your lens, the harder it is to hold steady. Try staying wider. If shooting pelagic black water video for the first time, I recommend a macro lens with a focal length of 30mm or wider, especially if using a flat port. With a little experience, you may decide you want to bump up to 60mm, but breaking out the big guns on the first few dives is going to result in major disappointment when you play back the footage.
Pelagic black water diving is definitely one of those times when shooting in full manual is encouraged. If you aren’t comfortable shooting in full manual, be sure to set some limits on the automatic settings of your camera. One option the Sony a7S II allows for that I found very handy is manually setting both aperture and shutter while using auto ISO (gain). This produces much better results than shooting in Shutter Priority (for motion blur control) or Aperture Priority (for depth of field control) as you can lock in both, yet still don’t have to manually adjust your exposure for every shot. The time you have with each critter is extremely valuable as you may only get 8-10 seconds before it drifts out of your reach, so every fraction of a second saved means you can spend it on composing and holding a shot.
Because macro video (and photo) has a very shallow depth of field to begin with, you are absolutely going to want to stop down your aperture to somewhere around an f/13. This will vary slightly based on image sensor size (larger image sensors have a shallower depth of field) and focal length. Unlike photography where you are capturing a single moment in time, with video you are capturing several seconds of time. Within these seconds, there is a lot of movement that takes place, so give yourself as much depth of field as you can get!
Within the automatic ISO setting on the a7S II, the camera allows both lower and upper limits. I set the lower limit to ISO 100 and the upper to ISO 12,800. ISO 12,800 sounds insanely high when compared to DSLRs like the Canon 5D series, which has been touted for its low light ability, but the a7S II does an amazing job at these higher sensitivities. I’ve found through both test shoots and trial and error, that ISO 12,800 introduces an acceptable level of noise to the image while still remaining usable on professional production standards. If you choose to shoot with auto ISO (or gain), be sure to look for an upper limit restriction and take the time to research what is acceptable for your specific camera model. Every camera is different, so don’t just take my word for it. It would be an awful feeling to get to a computer after the dive to find that all your footage is useless because the ISO was set too high.
If you choose to shoot with ANY automatic exposure settings, be sure to set your exposure value (EV) to -2. With specs of light on a black background, the exposure meter in every camera will tend to expose too high to compensate for the massive amounts of darkness. Another option, if your camera has this feature, is to change the metering mode to spot. In this mode, the camera will meter the exposure based on a small area usually in the center of the frame. However, this does not consistently produce good results as many creatures will spread out across the frame without a good exposure reference in the middle.
With exposure comes lighting. There are many species on the pelagic black water dive that produce their own bioluminescent light. The output is very dim and not enough to fuel the camera sensor. Bringing your own video lights is a must. You can shoot with one, two, or even several lights. Regardless of how many lights you choose to shoot with, they should be positioned just like you would with any other macro shoot – angled from the side, top, or bottom and set to fill the area where your macro lens is capable of focusing. Some black water photographers and videographers I spoke with prefer to shoot with just one light. I found that my personal preference was for two. I used two Light & Motion Sola 2000 Video lights with one positioned at 9 o’clock and the second at roughly 1 o’clock. The light at 9 o’clock I set at 1000 lumen output (the second brightness level setting) and the light at 1 o’clock I set at 500 lumen output (the first brightness level setting). This did a really nice job of illuminating any translucent bodies, yet was still not too bright to overpower most of the bioluminescence.
I wrote in Part 1 of this article series about being mindful of where your lights are pointed. This is certainly true for video lights. With a video camera in your hand, you can just as easily become the most despised diver as you can the most liked diver. Taking over the entire space under the boat and constantly flagging other divers with your lights very well may end your dive early. Being respectful of the other divers by keeping within your space and not allowing your video lights to shine in their face will possibly result in footage of some cool creatures you missed, but someone else alerted you to.
Solid focus is critical to any good video. Increasing your depth of field by stopping down the aperture is a great second step to good focus. The first is a lens with fast auto focus paired with a camera with a fast auto focus sensor. Many black water photographers recommend using manual focus because instant, single shot auto focus on a small subject can be very difficult to obtain. In video, we deal with continuous auto focus, and this is a must for all but the most experienced underwater videographers. Even at f/13 or f/20, depth of field (the area perpendicular to the camera sensor that’s in focus) with a macro lens may only be one or two inches. This allows for very little wiggle room to compensate for two independently moving objects, the subject and the camera. Shooting in manual focus means the camera must remain the exact same distance from the subject through the entire duration of the shot for the shot to be in focus. A lens with fast auto focus, paired with a camera that also has a fast auto focus sensor, will allow for much more “error” in tracking the subject and will result in longer usable shots.
Getting the shot
Your camera rig is set, tested, and ready to go. Your buoyancy is so good your dive buddy swears you’re a fish. Half of the challenge is now complete. The second half is acquiring some amazing footage. The technique for this is as unique as the dive itself.
The first task is to figure out which way the current is moving. Oftentimes it will be subtle. Hover next to your drop line and slowly look around, searching out the direction in which the plankton soup is moving straight towards you. The effect is similar to the old school Windows 95 star field screen saver. Once you figure this out, swim straight into the current. Go as far as the tether will allow, holding your camera in the ready position. Scan the area in front of you for anything bigger than a spec of dust. It takes a few minutes to figure out exactly what to look for, but once you do, there is stuff everywhere!
Avoid the temptation to move quickly from one subject to the next. Rather, pick one to focus on. Find it out in front of you far enough that you have time to hit record and frame the shot. If you have to swim to a subject don’t swim too fast as you can very easily overshoot and miss any opportunity. Keep in mind these creatures are more or less powerless against the current. They drift along wherever the ocean currents take them. Turbulence created by moving through the water can very easily send the one you’re after into a tumble that is both unnatural and nearly impossible to follow.
Once you lock onto a subject, stay with it by hovering motionless as you both drift along through the current. Hold the shot steady until you can no longer follow the subject. The best approach I found is to let the subject drift underneath of you. This is where Jedi-like buoyancy skills come into play. If the subject goes above you, you will not only get your exhaust bubbles in the shot, the turbulence created by the bubbles will make your subject look like it’s in a washing machine. With breath control, position yourself just above, so as the subject drifts by you can follow until the tether holds you back. Don’t be afraid to ascend or descend through the water column to stay with the subject, however, do be careful to do so with great control. Ascending too fast could result in decompression illness, and descending too fast could result in a blown ear drum. With a little practice, you can expect to have an 8-10 second shot for every subject you’re able to lock in on.
My recommendation for shot composition for the first several dives is to keep it simple. Creative, unique angles are a fantastic goal to have, but add in an entirely new layer of complexity on an already complicated dive. Try to focus instead on getting steady, in focus shots of whatever angle is presented to you. In my opinion, it’s better to walk away with something “average” than to walk away with a failed experiment. After all, the “average” shots in a pelagic black water dive aren’t that average!