As underwater photographers we tend to take what amounts to specialized studio lights down to our underwater studios, also known as the dive site de jour. A fairly common underwater setup has one or two strobes mounted on arms that allow the strobes to be positioned either closer to or farther away from the housing that holds the camera that we are shooting underwater.
If we were shooting topside, by moving the strobes off the camera we would find that we are able to better control the amount and quality of light that is hitting the subject. In topside shooting, generally we get better images if the strobe is not on top of the camera. Joe McNally, a well known studio photographer says: “Any light that originates at the camera is unflattering because you are literally throwing light at your subject.” You are not making a picture you are reducing your camera to the level of a copy machine.
Underwater, we find that moving the strobes off of the top of the camera housing helps us cut down or eliminate back scatter. The water we dive in whether it is fresh water or salt water generally has particles in it so if we are not careful we can highlight all the particulate in the water. Thus if our light source is coming from the camera, that great fish portrait we thought we got, looks like a fish in a snow storm because we illuminated the backscatter and maybe the fish. Yes, some back scattter can be cleaned up in post, but it is generally much better to reduce or eliminate the back scatter while we are shooting so we don’t have to spend hours in post trying to fix it, if it is fixable at all.
In general, underwater we re-position the strobes depending on how close the subject is to the camera. If we are shooting wide angle, the bigger the scene, the farther out to the side we position the strobes. The closer the action is to the camera, the closer we tend to bring the strobes in to the housing unless we are doing inward lighting for instance. (Inward lighting is turning the strobe heads in toward the camera so that the cone of light coming out of the strobes only lights the subject with the edge of the cone of light).
Topside photographers have long used multiple light sources and also use light shaping tools to help them manage the light resources that they use to create images. When I first started hearing the lingo of studio photographers I started to wonder if I would ever understand it, let alone understand what the various tools of the trade did and how they were used. The first time I heard a description of how to get a shot using two soft boxes, a rim light, barn doors and a snoot, I though oh boy this is going to take a while to figure all of this out. Well that is true, with any light shaping device there is a learning curve. Joe McNally’s book “The Moment it Clicks” is a pretty good book on understanding some of the lingo and concepts of shaping the light for topside photographers. According to Joe: “A snoot is any device that forms a tube around your light source to funnel it and make it more directional.” p. 28 n.2.
Why would we want to make light more directional when we are shooting underwater? Usually it is because the background that the critter we found is in either a confusing background or one that detracts from the image.
For underwater photographers snoots come in about 3 different varieties, all of which are designed to make the light that comes out of your strobe more directional. The simplest designed snoots look like a funnel from your kitchen that attaches to the front element of your strobe. A slight refinement to that design has an internal laser aiming light. Cool more technology, another battery to carry. At the time I first bought a snoot, the snoot with the laser aiming device would not fit my strobe. So I went with the simple funnel design.
A somewhat more complicated design is the snoot made by Retra. In addition to providing the underwater photographer a variety of sizes and shapes of light that come out of the snoot, Retra also adds a lens that helps focus the light. One aspect of the Retra snoot that is obvious even when you first pick it up is its weight. It weighs a lot more than the other snoots on the market. Underwater, weight can be compensated for using float arms or floats, but it is something that you will want to try to compensate for otherwise you could find that it is difficult to have your rig balanced which can add another layer of difficulty to the project of shooting with a snoot. The blue ring octopus above was shot with a Retra snoot. As you can see Retra makes snoots for quite a few strobes.
The third design for a snoot is to use optical fibers inside one or more arms that allows the photographer to bend the arm or arms to aim at the subject.
So how do you use a snoot. Generally what I was taught and what I have seen a number of underwater photographers do, is attach the snoot to the strobe on the opposite side of the rig from camera shutter release button. From there it was try to position the strobe with the snoot attached so the light comes out either as top light aimed down at the subject or at an acute angle. Aiming a snoot in this matter seemed to me somewhat akin to patting my head and rubbing my tummy. With my left hand I was trying to aim the snooted light and with my right hand I was trying to control the camera and take a picture. Once the snoot was properly aimed then snap the picture — easy right, not really.
Fortunately for me the first time I was using a snoot the dive guide who was locating the critters for us helped me aim. So assuming you have to aim the snoot by your self are there any suggestions? Yes, find a pebble or other small item at the start of the dive. Aim the snoot at the pebble and through trial and error get the snooted light to illuminate the pebble so you can take a picture. Then what you do for non-pebble subjects is use the same set up and the snooted light should be pretty close. Adjust as you take shots. On a dive site with no current and a subject that is not moving at all that approach will probably work. The problem is that to the extent we have current or we have to do much swimming to get to the next subject there is a pretty good chance the strobe arm with the snoot will move a bit. Since you are narrowing the cone of light it seems to me that we could spend a lot of time trying to deal with snoot positioning and a lot less time focused on the subject. Is there a solution? Perhaps.
Ask almost any engineer and they will tell you that one of the most stable shapes is a triangle. So in this set up, our snoot base starts with a triangle which uses two float arms attached together at the top with a triple clamp. The two float arms are attached to the housing by single clamps which as you can see forms a triangle using the camera housing as a base. The triple clamp at the top attaches to a short extension tube which connects to a clamp and then is attached to another extension arm. The extension tube is then attached to a clamp which is attached to the strobe. The strobe with snoot is pointed down towards the subject and once aimed the clamp attached to the snoot can be tightened so the snoot will not move. On the extension tube that is closest to the strobe you will probably need to add some floats otherwise the strobe will cause the rig to be top heavy and be constantly leaning forward. Alternatively, you could use a float arm as the last extension tube which would provide buoyancy so the strobe will be less likely to cause the rig to lean forward. The concept for this arrangement of the float arms is referred to as the “wolf” set up and was developed by Ze’ev Kirshenboim. After testing out the wolf set up I think that is provides a very stable base and it simplifies the aiming problem. Instead of having to think about aiming in three dimensions it limits the aiming to forward and backward.
What I found from experimenting with the wolf set up is that even with objects that are less than a 1/4 inch across, the aiming could be done reasonably effectively.
The image on the left is the unrestricted snoot. The image on the right is the image shot with the restictor on the snoot. For my shooting process, I think I will probably shoot without the restictor and then tighten up the shot, assuming the critter is small enough, and will use the restrictor in subsequent images. Now the water in North Texas just needs to warm up a bit and I will go back in the water.