Monday, 22 August 2016

Shooting Through Stone

 Hi All,
Some years ago, during a visit to Tintagel, my son Ben picked up a sliver of polished stone which was on the path leading to the castle. The stone was quite small in size (approximately 1” wide and 2.5” long).

That piece of stone has lived with us for the last 10 years, sitting on the lounge windowsill occasionally getting dusted. In all that time I’d never noticed that the stone was actually transparent until one particular afternoon when the sun hit it and I was in a position to see a beautiful blue colour through its centre.

Now having seen the colour through the stone, how was I going to create photograph that would bring out the best of the colour?

Initially I thought I’d try to shoot it against the window with the natural light of the sun. I set up the camera and balanced the stone with a piece of blu-tack but I found I couldn’t control the light sufficiently to get a satisfactory image.  

Next my thoughts turned to using a strobe. At least with a strobe I can control the power either directly on the unit itself or remotely. I have a few different triggers available so I decided this was the way to go. 

I decided that I would use the strobe to illuminate the stone from beneath, mount the camera on the tripod using the 90 degree boom so that it was looking directly down on to the stone. The only problem I could foresee was how to stop the excess light from the strobe entering the lens. 

I resolved this by using a piece of A4 black card. I traced the outline of the stone onto the card with pencil then using a sharp craft knife I carefully cut the shape making sure I remained inboard of the lines ensuring that no direct strobe light would reach the sensor.
The final set up comprised a piece of A4 sized clear Perspex clamped to the dining room table. The black card was placed onto the Perspex and the stone placed flat on to the card over the cut-out.  

My SB-910 speed light was placed on top of a small box under the Perspex and positioned directly under the cut-out. The speed light was set to iTTL remote and a Nikon SU800 commander used to trigger it.

The first exposure was made using a flash set at ½ power which resulted in a very over exposed image with little or no detail in the stone. Four subsequent exposures were made decreasing the power of the flash until I achieved an exposure I was happy with. The final settings were 1 second @ f22 

Next time we're shooting macro shots of bedding plants with the Nikon R1C1 wireless close-up flash system.

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