Backlighting Fun: Glass Shards

Final Result, hit the jump to find out how it was done

I had some fun yesterday with a glass shard that I took from a car's broken windshield. When I saw the broken pieces of glass I immediately thought of my macro lens and flashes, click through to see what I did.

I decided to start by putting this piece of broken glass on a glass table and take an ambient light only shot, I used my newly acquired Manfrotto tripod with a ball head (review coming soon), set the camera to aperture priority mode, chose f/10 for a large depth of field, set ISO to 100 (no need for a higher number since nothing is moving) and finally I used the self timer to prevent camera shake and fired away, this is what I got:

Same piece of glass, ambient light only

The above picture looks nice but is not striking enough, so I decided to go on with my plan and use flashes, I had a vague idea about how to light this piece of glass, but I knew that I had to light it using two flashes and that one of them should be from beneath.

I started with one flash only at 1/32 power and the shutter speed at max sync speed to kill the ambient (the rest of my settings were the same, f/10, ISO 100), and started taking pictures and pointing my flash from different positions, left, right, up and down. After looking at the differences I decided to light the glass with one flash from the right side at 1/32 power and zoomed to 14mm (using the diffuser panel), and another flash from the bottom left at 1/16 power and zoomed to ~ 70mm. Here's how the setup looked like:

I also tried different gels on the flash for more interesting colors, I ended up with a blue gel on the top flash and a red one on the bottom one. To compensate for the lost power due to gels I increased the ISO to 200. The gels I used in this setup are home made, I posted about them here.

POST PROCESSING

I had to do some post processing to get the image at the top, a macro lens (close focusing distances in general) plus flash lighting have a maddening ability to show every-single-speck-of-dust!!!
I cleaned the table several times, yet it was never clean enough, so I decided to ignore it and remove it in post.

Post processing was very easy, I did a strong bit of sharpening (more than I usually do) to show the inner fractures inside the glass shard, and then I used the adjustment brush with exposure = -4 to remove all the dust specs and undesired reflections around the glass shard, it also helped to pull the fill light slider all the way to the right to see what parts needed removal with the adjustment brush. Here's the final result again for your convenience:

Final Result, click to see a larger version

I believe that this is a mediocre result, nothing spectacular, but nonetheless it was a fun experiment and I consider it as a new ground on my way to improve my product photography skills. What do you think?