Portal to Another World

The amazing Natural Bridge at dawn under the moonlight and the rising sun. It is a naturally formed rock arch over Cave Creek, a tributary of the Nerang River. It was formed from a waterfall which undercut a cave beneath the waterfall and dug a pothole on top, until the two joined and the creek flowed through the cave, leaving an arch across the front. The bridge is located in Springbrook National Park in the Gold Coast hinterland of Queensland, Australia. This first shot above was taken just before dawn to minimize the differences in light level (dynamic range) inside and outside the cave. It is a three shot panorama taken at 30mm using a Canon EF 16-35mm f/2.8L II at ISO 100 and f/16 with an exposure time of 20s. All shots on this post were taken with a Canon EOS 6D.

In the middle of the night the cave transforms as glow worms dot the roof of the Natural Bridge shining like stars. This shot is a single very long exposure with a touch of gentle moonlight flowing into the cave. The colour dichotomy is a result of the green rainforest reflections contrasting with the subtle blue from preferential scattering of short-wavelength light as it hits the the waterfall mist in the moonlight. The glow worms (Arachnocampa flava) are actually a fungus gnat species which have a luminescent larval stage. The genus of Arachnocampa means "spider-worm," for the way the larvae hang sticky silk threads to ensnare prey. They are endemic to New Zealand and Australia, dwelling in caves and grottos, or sheltered places in forests. This is a single shot taken on with a Samyang 14mm Ultra Wide-Angle f/2.8 IF ED UMC at ISO 400 and 84sec.

As described above under the moon light the subtle blue is a result of preferential scattering of short-wavelength light travels down the vertical shaft and hits the waterfall mist in the moonlight. The shot below shows a close up of the waterfall in the moon light. The log was jammed in the entrance to the cave after flowing down during floods.

These last two shots were taken in the full bright daylight from outside the cave the next day after spending most of the night in the cave. The bright daylight now highlights the white reflected from the water fall now. The first was taken at 16mm with the Canon EF 16-35mm f/2.8L II at ISO 100, f/8 and a short 1.6 sec exposure.

While the last one was taken at 16mm using a Canon EF 16-35mm f/2.8L II at ISO 100, f/7.1 and 0.4 sec.

The daylight shots are a blend of multiple bracketed exposures layered using luminosity masks to expose the scene properly given the high dynamic range between the light levels inside of the cave and the rain forest outside.

I don't normally take so many shots of a single waterfall but Natural Bridge really is a special place. The park is situated on the McPherson Range, near Springbrook, approximately 100 kilometres (62 mi) south of Brisbane. If you have any further questions on the techniques used here please drop me a note in the comments !

Rob Downie
Love Life, Love Photography

_{All images in this post were taken by and remain the Copyright of Robert Downie - http://www.robertdowniephotography.com}