The Sustained Illumination of the Rumble Room

Nathan L. Williams

NSS 52960, Huntsville Grotto, www.realmsofreality.com

Published in May 2007 NSS News

The Rumble Room located in Rumbling Falls Cave is the second largest cave chamber in North America.

Last year I wrote an article on lighting the Topless Dome of Tumbling Rock Cave using high powered spotlight allowing it to be photographed. For this years article I hoped to scale back on a huge scale. This will become more clear as you read on. It seems like every now and then something comes along that offers to make a challenge much easier and less arduous and at the same time seems so absurd that it borders on the edge of reality. It is these opportunities that I live for.

A recent trip to Rumbling Falls Cave offered one such adventure in photography. On this trip with our group of four, there would not be sufficient manpower to sherpa the conventional flash equipment need to light the Rumble Room - a massive five-plus acre room with a dome of two hundred feet. It was the restrictions in the amount of equipment that carry in that led me to develop a new grand scale lighting system. At the center of this system was the LED.

Last year I had shot several helectites using nothing more than a single unfocused LED. I felt the results were very unique and attractive. The colors we right on and I could see the scene in real time unlike with a strobe or bulb. Later we did some experimenting in larger areas, again with positive results. At the time I figured this could be handy for small to medium passage shots but honestly didn't give it much thought. It would be a visit to Rockcastle County, Kentucky that would spark my interest in using the technique again. We visited the Great Saltpetre Preserve in late October for the annual Halloween party. I decided to pack a custom LED module in my gear and try some things while I was there. A module consists of a single 3 watt LED with associated electronics, heatsinks, and battery pack. While at Pine Hill Cave we tested the LED technique in conjunction with the strobes, again with positive results. This was in medium passage and added a nice light to the scene. Later in the day we did a minute and a half exposure test in the Echo Auditorium chamber of Great Saltpetre Cave. I locked the shutter open and moved around the room which is roughly the size of a football field. The picture was exposed pretty well aside from the nasty light streaks from me moving , overall not a bad image. It was this simple test that got me thinking. I didn't have a trip lined up then to push the technique any further but that would soon change and I would find myself in a situation of opportunity as well as overwhelming emotion.

Around the middle of January a few from the local grotto decided to plan a trip to Rumbling Falls. The trip date was February 3rd, giving me just over two weeks to develop the necessary equipment that would allow me to photograph the Rumble Room using this technique. At first I didn't tell the others in the group of my plans to try and illuminate the chamber in the event I couldn't pull it together. My first order of business was to get a rough calculation of how much exposure time I would need for the amount of light modules I could afford to build. I narrowed it down to ten minutes exposure with 15 LED modules.

Now I needed to order some of the brightest, most efficient LED's I knew of. Last year I built a custom helmet light using Lumileds Luxeon Star LEDs. These worked very well and I had also used one for the photo tests mentioned before. With that data in hand, I ordered 15-3 Watt LEDs and prayed they would arrive by the following weekend. They did and I was able to rush build four prototypes for testing. We first tested them in a friends backyard with promising results. Backyards and caves are very different though and it was nine days until the trip to Rumbling Falls. I had only time for one much needed in-cave test trip. That test would be in Tumbling Rock cave located in Jackson County, Alabama. I knew of a sizable room in there that might offer a good scaled down test. The test room measured roughly one hundred feet across, sloping down at the middle. We placed the four prototypes on the camera side of the downslope of breakdown and faced them across to the other side. When the LEDs were turned on you could see the entire scene fairly well. I thought to myself "this looks very promising." The camera was set up and a test shot lasting two minutes was conducted. The results surprised me. The shot was actually over exposed. "Hmm light to spare" I said to myself. I think that's the first time I've been so excited to get an overexposed shot. It showed me that I had light to spare with a shot of this scale. All the time I kept telling myself that I would have eleven more modules than I have now. It was at that point that I really started believing that it could be possible to pull off the shot in Rumbling Falls. All that stood between my goal now was building the last eleven LED units and my physical ability to get through the cave itself.

With the equipment finished, tested, and packed it was now time to depart on the adventure. There could be no more second guessing at this point. It would either work or it wouldn't. We were on the road and there was no turning back now. The trip leader was Andrew Linsenmeier, a veteran to the cave who had helped me on photo trips in the past. He would guide us to some interesting sites within the cave. As we entered Rumbling Falls I kept remembering of how I would dream of this place. In many of those dreams the cave seemed like a huge nemesis, tamable only by a select few. Personal phobias tried to control me like a puppet on strings. I tried to tell myself it was ok to be uneasy. After all, this was not an easy cave. As we negotiated the drops, climbs, and crawls, I gained an immense respect for the cave photographers who had traveled there before to shoot the cave. Guys like Chris Anderson and Willie Hunt to name a few had shot some amazing images in this place. It had not come easy for them. The cave seems to have a personality and it will make you work hard for anything you get. After a couple hours we reached to top of Stupendous Pit, a 200 foot drop into the ink-black void. I recall the sensation as I left the wall into the free rappel of how different it felt not being able to see anything pretty much the rest of the way down. you have so much space around you that your helmet light is of little use. You see yourself, a little bit of rope above and below and that's just about it. It's honestly indescribable. After landing on the huge pile of breakdown we took a break and had a bite to eat. We would not be shooting here at this point in the trip. Earlier in planning it was decided to attempt the Rumble Room shot on the way out. For now it would have to wait. Rumbling Falls is an amazing place. It seems as though three separate cave systems merged together to create the roughly sixteen miles of passage, rooms, squeezes, and drops. At the bottom of the system is a large river that gives the cave most of its distance. We traveled down a section of this for several hours to visit and photograph some of the various areas of the cave. The water was very cold and it was slowly working on us. On the way back to the Rumble Room I got to the point where I doubted we would take the opportunity to attempt the shot. I was cold, exhausted, and could sense the same from the rest of the group. It was late and we had been on a long trip. Reaching the top of the breakdown pile in the Rumble Room we rested and ate one last meal.

It was then that I got a shock and a boost all at the same time. Sitting on a rock, cold and damp, was Sabrina Simon. She is a short slender caver and thus had to deal with getting more of her body wet than the rest of us. I knew she was cold and tired. Slowly she looked up at me with her usual grin and said "well I guess you better get that picture". Now Sabrina was not new to my photo projects. She knew all too well that it would take a while to set up and execute. The wait for here would most likely be miserable so when she showed signs that she thought it was still going to happen, it was like a kick in my rear! I was my biggest doubter. The team still believed in me, so why couldn't I? It's amazing how fast you warm back up when you get really motivated. Helping me was Jimmy Romines. He had been there when we did the first tests back in Fern in 2006. Now he was placing the modules out around in a perimeter shape about 75 feet off the wall. After we got about seven modules placed, I heard Sabrina say "Oh Wow! Look up!" Worrying about where I was stepping, I hadn't bothered checking things out overhead. As I looked up you could already see that the place was lighting up. Seven modules were placed and you could already make out the entire room. My eyes began to tear up as I paused for a minute to try and understand what I was seeing. It's not too often a caver has to try to understand what he or she is seeing. This place is so huge that it was difficult to believe it was real. All I could do was stand there in awe.

As Jimmy finished placing the last of the lights, I set up the camera. I got an idea to do a two minute test shot. It would serve as a benchmark like the other ones I had shot during testing, which were also based around a two minute exposure. Surprisingly the first image was fairly well exposed. You could see the whole room and some of the lights. The calculations we way off. I knew then that it wouldn't take ten minutes to expose the image. I did another test for three minutes while Jimmy finished tweaking the lights to reduce flare. After looking at the tests I decided on a five minute exposure. I asked Jimmy to model in the scene for scale. It seemed appropriate. He had been there all along with Sabrina in Fern Cave when I got all excited about shooting a tiny helectite and now this seemed like some sort of grand finale - the culmination of conception, development, and testing. It all came down to fifteen tiny LEDs lighting the Rumble Room. We got Jimmy placed and an announcement was made to turn off all non-scene lights. There we were - just standing in awe. The Rumble Room was rich in color as I had never seen. At that point it it didn't really matter to me if we got a shot out of it. Just being there with the whole thing lit in real time was reward enough. A beauty and a sight that could bring many to tears aren't easily obtainable. At that moment I thought about how nice it would have been to have the photographers and sherpas from the various photo trips there to see the place all lit. After all, it was those folks in my mind who really deserved to see what I was seeing. As the shutter opened one last time I told myself it was worth it. Dealing with all the phobias, the freezing cold water, the exhaustion, this sight made it all worthwhile. The shutter closed for the final time in Rumbling Falls and we started collecting the LED modules. One by one the lights we shut down and slowly the massive chamber went back to sleep, waiting for the day when someone would return to re-awaken her yet again. It would be a few more hours before we reached the mouth of the cave. We had just shot her stomach and I was a very happy caver. Total illumination time was one hour and twenty eight minutes. Before this experiment the room had only been lit for about 2-3 seconds when Chris Anderson's crew set off the mighty Meggaflash bulbs. I now know how he and his team felt as they could see the place lit for a few fleeting moments. We left Rumbling Falls with more than just a shot of the Rumble Room. We left we left with an experience that can't be described. We felt a sense of teamwork, friendship, and accomplishment. Rumbling Falls felt like a friendlier place. Even though the LEDs only emitted eighty lumens each, several used together made another dream a reality. This is only the beginning for what we have dubbed the Sustained Illumination Technique or SIT Lighting.I hope the small lightweight device will allow the deep explorers around the world to return to the surface with amazing images of the most remote places they have visited. It is lightweight, portable, and very robust. The fifteen LED's used to light the Rumble Room fit in the palm of ones hand and fifteen complete modules fit into one 1400 series Pelican case. Fewer modules can be used and now more powerful LEDs with similar power consumption are available. We are working on other uses for the lighting such as illumination of pools, rivers, and waterfalls within caves. When working with long exposures, there are also a few limitations. Motion in a shot can also ruin it. Due to this I decided not to go with the model on the rope. The model is in the very back of the room directly across from the camera. On the upside, motion in the shot is now possible. This is sometimes a desirable effect usually associated with cascading water and waterfalls. Also to be able to see your scene in real time is priceless. It feel almost like the jump from film to digital in that there is instant feedback. As with any photography, try new things. Don't feel confined to rules and restrictions. Experiment with things. What you end up with may be far more than a print on your wall. It may lead you to an adventure that will last a lifetime.

I would like to thank some special people for their help with this project. Steve Pitts and Brandy Hulsey donated the heatsinks needed to cool the LED's and electronics. Davey Johnson aided with module fabrication and surface testing. Ronnie Gregg, Mark Ostrander, Roger Graham, and Jimmy Reyer helped conduct in-cave test during the trip to Tumbling Rock. Thanks to Chris Anderson and Willie Hunt who through their creative ingenuity inspired me to come up with that of my own. Finally Thanks to Andrew Linsenmeier, Sabrina Simon and Jimmy Romines for their in-cave support and contributions during our trip to Rumbling Falls. Only as a team was this possible. I will remember and cherish it for the rest of my life.