Ben and others, below is the back story on that image and why the sandy floor looks like that --- but first, I didn't name that particular image "Burning Bush" because I already have this one I call "Burning Bush"
D):
Back story for "Passage of Time":
This shot was made in June of 1998, early in the morning. At that time, I was shooting film and this particular image was made with a Mamiya RZ67 and 50mm lens. The film used was original Fuji Provia, nominally rated at ISO 100. However, as with most tranny emulsions from that time, Provia suffered pretty significant reciprocity effects -- meaning that at very long (or very short) exposures, the rated film speed slows down significantly AND requires filtration to achieve correct color balance. This particular section of Upper Antelope Slot Canyon is very dark to begin with, and darker still due to the relatively low angle of the Sun not shining directly through the ceiling slot. Anyway, the resultant reciprocity reduced the effective ISO to about 12, and then the strong warming filter sucked up another stop or so for a net of ISO 6, so this exposure ended up being 6 *minutes* at f10.
Now to the etherial looking or ghosted sand on the floor. The slots are open to the public, so at any given time you can have none, a few or several other people in the canyon with you, and no real way to prevent them from entering your images unless you point the camera up. The upside is that most motion is not captured in a frame if it is present for less than 1/8th the total exposure. In this case I had maybe 8 people walk through this image as I was exposing it, yet the only static evidence of their passage was their overlapping footprints left in the sand.