Introduction: Fiber Snoot for Underwater Photography

I originally published these instructions a while ago on my blog, but I figured that I will be more useful here :) 

Following a friend’s request I decided to explain how to build a fiber snoot for underwater use. On this post I will explain how to make a snoot that fits an Ikelite DS-50 substrobe. 

I first saw the results of using a snoot for underwater macro photography a few years ago, when I met one of the most talented and creative underwater photographers I know – Keri Wilk. We participated in the annual Epson Red Sea competition – an underwater shootout that takes place in Eilat (Israel). Keri took some amazing photos using his snoots, and he later explained his technique in a blog post on DivePhotoGuide.

I wanted to experiment with snoots and build my own, but instead of using plastic tubes I decided to use fiber optic cables. With fibers, I can place the strobe anywhere and then just use the flexible Loc-Line “arms” to point the lights anywhere I want.

Step 1: Materials

What you will need:
  • Ikelite DS-50 / DS-51
  • Barrel Plugs/ round ribbed tubing plug to use as an adapter for the snoot. I do not know the technical name for this part, but I found a nice white plug in the plumbing department in Home Depot. The one I used has a 99 mm diameter, which fits nicely on the DS-50. You can see it here and here.
  • Loc-Line parts (for snoot “arms”)
    • 27cm of 1/2″ segments, 1/2″ NPT Connector, 1/4″ Nozzle. Check it out on this page.
    • 41cm of 1/4″ segment, 1/4″ NPT Connector, 1/8″ Nozzle. Check it out on this page.
  • Solid core jacketed fiber optic cables. I ordered mine from Fiber Optic Products:
    • 47cm of 4mm cable (EGS4B)
    • 35 cm of 7mm cable (EGS7B)
  • 23cm of thick (5mm) rubber band, 1.8cm wide. We will  use this piece as a spacer between the strobe and the snoot adapter
  • Optional – metal/plastic nut to secure the NPT connectors. You might need to get creative here.
  • Velco straps (optional)
  • A small saw
  • Drill
  • A conical drill bit that can make 12mm and 20mm holes

Step 2: Adapter and Arms

First, we modify the plug to act as an adapter that connects the Loc-Line arms to the DS-50. Use a saw to cut out a piece from the side of the plug to match the bulge on the strobe and the TTL cable connect. This cut serves two purposes – it allows you to slide the strobe all the way in, and it prevents the adapter from rotating.

Now, carefully mark the positions where you want to place the two NPT connectors (the base of the Loc-Line arm pieces). This step is a bit tricky because you want to place them exactly above the flash tube. I used a small schematic to mark the centers of the holes.

Use the conical drill bit to drill a 12mm hole for the 1/4″ arm and a 20mm hole for the 1/2″ arm. Screw in the NPT connectors. Don’t worry if the holes are slightly too big – you can always secure the connectors using nuts (or SugruNPT connectors).

Note that the nuts you use must be narrow so they don’t scratch the strobe itself. I used a metal nut for the small NPT, and for the larger connector I used a plastic one that I cut from a gardening hose adapter.

Connect the arms and nozzles to the NPT connectors and push the fibers in. If the 7mm fiber is too wide for the 1/4″ nozzle just cut nozzle – it gets wide the closer you get to the base.

Glue two strips of Velcro on the adapter, as shown on the photo.

Step 3: Preparing the DS-50 and Connecting the Adapter

Place 4 strips on the DS-50 (as shown in the photos). I used “soft” Velcro (the loops) for both. Prepare two 40cm strips of “rough” Velcro (the hooks) – we will use them to attach the adapter to the strobe.

Place the think rubber band on your the DS-50, as a spacer. It should fit nicely on the gray shoulders around the glass. This spacer will protect the strobe’s glass from the nuts and connectors. Again, you can use Sugru or other materials instead.

Now place the adapter on the strobe and use the long Velcro strips to secure it.

All done!

Step 4: Tips and Examples

I found it convenient to use a GorillaPod as an underwater tripod as  it can easily be placed anywhere. Be careful not to place it or corals.

If you look closely at the first photo, you can see the 4mm fiber pointing on a small Blenny hiding inside the  long plastic tube