Sunday, March 9, 2008

The Tiny Turbopump

Intro


Last week I was asked by one the program leads at work to shoot some pictures of a tiny little turbopump used to pump cryogenic hydrogen to cool optical equipment in satellites. This thing is a shaft with a radial compressor etched on one end and a radial turbine etched on the other end. The shaft is supported by 2 hydrodynamic bearings and one hydrostatic thrust bearing. Operational conditions involve rotational speeds of about 1 million RPMs. Interesting stuff for sure, but as far as photography is concerned, all that high technology boils down to several small shiny metal parts. The shots were to be added to a promotional poster for display at an upcoming conference. There was not much time to work on it since on the day he asked me for the shots, the deadline was set to "yesterday". Lucky for him I always take my camera equipment to work with me...you know...just in case...


Thought Process


OK, as I mentioned before, this was a shot of small shiny metal parts and it needed to be done right there in the office and be delivered to the graphic designer who was putting the poster together by that evening. The equipment at hand was:
  • my D70s
  • 50mm f1.8 and the 17-70mm f3.5-4.5 (kit lens)
  • SB800
  • anything I could find around the office

I decided to use the 50mm just because it was already mounted on the body. I wanted to find a shiny black background because I thought that would contrast well with the metal parts. Now the issue is how to light it. As luck would have one of my colleagues had brought in a large white poster board for another promotional shot he had taken the day before. That's when it hit me. I could bounce the SB800 off the poster board to get a nice soft fill to light all the parts evenly. Then I could use the bounce card built into the flash to throw some light from the opposite side and create some highlights. All I needed now was the black shiny surface. Again, as luck would have it, the standard issue filing cabinet at the office is black and metal which makes it nearly the perfect dark shiny surface.

Execution

I placed the parts on top of the cabinet and used my camera bag (which is black) to prop up the white poster board at an angle over the parts. I placed the SB800 angled towards the poster board and extended the bounce card. The image below shows the setup.




I used the on board flash to trigger the SB800 in manual mode set at 1/8 power. The camera was set at F5.6 and 1/80 s at ISO 200 (manual mode).

Here are the results





Discussion

I was very pleased with the results of this shoot. For the first time I got results that looked like the kind of thing you'd see at strobist.com. Looking back I think I would have picked a higher shutter speed to make the black background darker. The images above had to have the background darkened in post processing. Let's see if the next assignment will come out as good as this one.