Monday, July 12, 2010

Smoke photography (Intermediate)

I finally tried smoke photography.  There are a few ways to do it - here's how I did it to get sharp smoke. Note: It has nothing to do with family photography, but it is a sample of an application of lighting knowledge.

1. What's needed.
a. smoke source. I used incense, although a cigarette can also be used.
b. flash (ideally an external flash for power and versatility). I used an SB-800.
c. a place shielded from wind, ideally one that isn't so bright, with dark walls, and with ventilation so that the smoke doesn't accumulate. I used our bathroom (which doesn't have a smoke detector).
d. optional: remote shutter release, tripod for camera.

2. Position the camera, flash, and incense.
a. Find a spot away from the wall.  The closer the wall is to the flash, the more likely the flash's light will illuminate the wall, making it harder to get a black background.
b. Position the incense reasonably close to the lens.  Smoke looks nicer when close up.  The smoke at the tip of the incense is also more organized - consider that in positioning the incense.
c. Position the flash close to the incense.  The close distance helps to increase the relative power of the flash to minimize ambient.  I positioned mine directly below the incense, and away from the lens to avoid flare.

3. Set focus. Focus is critical to getting a sharp smoke photo.  You need dim light to take smoke photos, and it's hard for cameras to focus a dimly lit subject.  Instead, put your hand or other proxy target over the incense, where the smoke will appear, and focus on the hand/target.  Once focus is set, switch to manual focus and don't change the position of the camera and the incense.

4. Set the camera exposure.
a. Set shutter speed to sync speed.  The idea is to kill ambient light to get a dark background.  1/250 for the D300.
b. Set the ISO to the base ISO. Again, we're trying to kill the ambient.  200 for the D300. 
c. Set the aperture.  A small aperture is needed to increase the probability that the smoke will be in focus.  A small aperture also helps to kill the ambient.  With a dark wall, I could get a black background with f/8.  With a light wall I needed f/16.

5. Set the manual flash exposure.
Because the position of the subject, flash, and camera don't change, I used manual flash instead for consistency, although TTL worked too when I tried it.  Using trial and error, I set the power to 1/4 for an aperture of f/16, ISO 200, or 1/8 for an aperture on f/8, with a distance of about 1 foot between the smoke and the flash.

6. Experiment with moving the smoke.
Try holding the incense and moving it, keeping it on the same distance to the camera to maintain focus.  When you get the hang of it, you can even take the shots handheld to get variety.

7. In postprocessing, consider cropping, using negatives (to get black smoke on a white background), and/or altering the color of the smoke and background.

UPDATE: Check out this related post on a secret tool for smoke photography

Sample shots: