Kent Loeffler is the photographer in Cornell’s Department of Plant Pathology and Plant-Microbe Biology.
Kathie Hodge is an Associate Professor of Mycology in Cornell’s Department of Plant Pathology and Plant-Microbe Biology.
For the past several years Kathie has been pestering me to come up with some way of capturing “a bug’s eye view” of the tiny mushrooms and slime molds that inhabit our upstate New York environs. She wanted these unique images to spice up her Mycology lectures and illustrate articles appearing on the Cornell Mushroom Blog, which she hosts and edits. This sounded like a job for a fisheye lens, which we already happened to have, so I often went out to the woods to crawl around in the dirt and try to get a critters slant on things. A few of these experiments were interesting such as this yellow Amanita and the Indian pipes poking up through moss, but overall they weren’t what she had envisioned. And it was a dirty job lying on the muddy ground trying to position a camera under a mushroom with things biting and crawling up my pants legs. “Oh well” we sighed and shelved the idea for another Ithaca winter.
Like clockwork, Kathie popped into my lab again last Spring expressing the desire for unique, bug’s eye views of mushrooms, but this time she added, “and I just got a grant to pay for it!” Well this was a whole new ballgame. I started researching unique lens systems on the web and discovered the wonderful world of borescopes, both rigid and flexible. Borescopes are devices used in industry for examining the insides of engines, rifle barrels, building cavities and people (in medicine they’re called endoscopes). As luck would have it, one of the largest manufactures of industrial borescopes is just up the pike in Rochester, NY, the Gradient Lens Corp. Doug Kindred, President of Gradient Lens, graciously invited me to his office for a demonstration of his line of borescopes and this is what I learned:
Borescopes are curious lenses indeed. Rigid borescopes are long tubes containing either a multiple lens system (Hopkins design) or a single tubular lens (endoGRINs Gradient Index Relay). On one end of the tube is a focusing eyepiece and on the other end is an objective lens. The objective lens is set to view straight ahead (0º Direction of View) or at a 90 degree angle (90º DOV). The objective lenses may be manufactured to produce different Fields of View from very wide angle (90º FOV) to a much narrower view (40º FOV). Borescopes are manufactured with a fiber optic channel running from an entrance port near the eyepiece to an exit port located adjacent to the objective lens. A light source attached to the entrance port will thus illuminate anything the scope is pointed at, even inside a deep enclosed cavity.
Flexible borescopes are composed of densely packed fiber optic bundles between an objective lens and eyepiece. These scopes are used to snake into and view hard to reach places such as jet engines or body cavities. The resolution of these flexible scopes is limited, however, to the number of fiber optic tubes of which they are composed, and this resolution is much less than that of a rigid borescope.
After mulling over all the possibilities, I purchased a wide angle (90º FOV), right angle (90º DOV), rigid borescope with camera adapter, light source, and digital camera back. This wide FOV lens would create the “fisheye lens on the end of a stick” imaging device we were seeking. Doug sweetened the deal by offering to sell 2 older scopes that matched my specs for the price of one (storage for old inventory was becoming a problem for him). I suspect he was also quite interested in our project as 99.9% of his sales are for industrial applications, the remaining .1% being our mushroom project.
Problems and Solutions
Working with the borescope in the field to produce high quality digital images presented numerous technical challenges. First off, I really didn’t like the quality of the images obtained with the point and shoot camera system that came with the borescopes. The Sony DSC-H5 camera produced beautiful colors but the autofocus system it employed did not provide sharp, critical focus when used with the borescope. Secondly, so little light passes through the borescope to the camera that I found natural light exposures were too long for hand holding in the field. Using a tripod to steady the camera during these long exposures was possible, but proved to be quite clumsy, especially when trying to photograph newts, insects, or tiny mushrooms close to the ground. Electronic flash solved this problem, but the on-camera flash of the Sony did not always illuminate the subject properly. Here are a few examples from these early trials:
To improve the quality of the imaging system I next adapted the borescope to a digital SLR camera (Nikon D2X) and experimented with different Nikkor lenses and illumination systems. After much trial and error this is the system that eventually proved to work beautifully with the borescope.
The camera and TTL flash are mounted on a bracket with flexible arm for positioning the flash. A 60mm Micro-Nikkor lens is connected to the borescope with a special adapter from the Gradient Lens Corp. The auto-focus function of the camera does not work properly with the borescope so the lens is set to manual, infinity, and wide open (f/2.8) aperture. Focusing is accomplished by rotating the focusing ring on the borescope itself. ISO is set to 400 and the shutter speed to 1/20th second. The flash provides the main illumination on the subject and the long shutter speed fills in the background of the deep forest. Instead of a tripod, I found that a beanbag works well to steady the system for the long exposures.
Being a scientific photographer, I thoroughly enjoy playing around with new toys (er, tools). This project was no exception and after several months of experimentation and dozens of trips to the field I finally began to be satisfied with the quality of the images the system was producing. I discovered that the borescope could focus extremely close, imaging tiny objects only a few millimeters from the lens. From this perspective, miniscule mushrooms appear heroic in stature, tiny newts become dinosaurs, and insects are terrifyingly beautiful in their complexity. Who would have thought that the brown slimy smudge in a log crevice would look like an avalanche of baked beans when closely examined. Using the borescope to poke around in nooks and crannies really opened my eyes to the complexity and beauty of the miniature world that exists everywhere underfoot. In keeping with this spirit of discovery, the images in this show are presented in circular form, representing “portholes” into this hidden world around us.
("Miniature Landscapes: Photographic Adventures with a Borescope," is on display in the Mann Library gallery through Feb. 27)
- This project was funded, in part, by the Faculty Innovation in Teaching Program, Office of the Provost, Cornell University.
- Many thanks to Doug Kindred of the Gradient Lens Corp. for providing the technology that makes these images possible.
- Special thanks to Noni Korf Vidal of CIT for all that she’s done for this project.
- Special, special thanks to Howard Raskin, Laura Larrimore, and Jan McCue of the Mann Library for helping to fund and prepare this exhibition and for providing the Cornell community with this wonderful gallery space.