Even more difficult: two flashes at the same time!

Back to my off-camera flash endeavors.

Pentax K10D + Zeiss Sonnar 85/2.8 + 2 off-camera flashes

I used two flashes on this photo, both diffused with an open white plastic bag. One was on the same table as the flower, to the left, and the other on a tripod, to the right and slightly higher. I tested different power ratios on both flashes, until I got the exposure I found appropriate. The camera was handheld, as I wanted to be free to try different perspectives.

Then I tried a version with more selective lighting. I put my cardoard snoot on the flash that was on the tripod, directing the light to fall just on part of the petals, and tried different positions for the other flash, still diffused with the plastic bag. After only a few tries I obtained something I liked, shown below. The fact that one can obtain instant feedback from the camera's display facilitates the flash use immensely. In the times before digital, it could be a complex task to accurately predict how the light would fall on the subject. To overcome that, photographers often used modeling lights, but these could still be difficult to adjust in order to properly reproduce the flash output.

Instead of flashes, one can, of course, use continuous light sources (regular tungsten even) to obtain similar results. However, flashes present some important advantages in terms of portability and versatility. Besides, the intensity of light delivered in a short burst allows for using short exposures and can even make the use of a tripod unnecessary. For the same effect, a continuous light source would need a high power rating and imply significant heat release, unless "cool lights" are used, like compact fluorescent light bulbs. Another problem might be properly correcting white balance when light sources with different color temperatures are used.