'Gloworm Mk1' Mine exploring headtorch
Gloworm has been underground a few times now, but on 10th March 2013, I had an opportunity to take some pictures with my camera and a tripod. I used the area at the end of the 9 adit in Rhosydd, aiming at the old incline.
For the test, I set the camera (old Fuji S5500 4Mpixel) to 1/4 second exposure, 300EV (F2.8) and ISO 100.
Then I took a series of pictures, starting with a standard Oldham head torch, then a Wiseled Tactical (which wasn't at full brightness, maybe 500lm?), then the Gloworm at 400lm, 1600lm and 11000lm.
To find out how much detail is actually in the pictures, I then processed some of them in GIMP by adjusting the contrast and brightness. This gives a better representation of what you actually see underground as you can see exactly where the light does reach.
The Oldham: (notice the dim yellow spot)
The Wiseled Tactical:
The Gloworm at 400lm:
The Gloworm at 1600lm (4x400lm):
The Gloworm at 11000lm:
And after a spot of post-processing
The Oldham: (still pretty dim)
The Wiseled Tactical: (useful)
The Gloworm at 11000lm: (basically the entire chamber is illuminated which is how it appears when you're there)