For anyone who is interested in smoke art, I have written tutorials on flickr that I will adapt and transfer here. This is Part 1: Photography or how to take quality pictures of smoke.
All of my Smoke Art starts with a photograph of incense smoke. Here are my steps:
I am using a dSLR and external flash. I understand that adequate smoke photos can be taken with an on-camera flash, but I have not done so.
1. I use incense. I started with cones and then tried sticks. They produce somewhat different effects. The cones make a little thicker smoke trail, but the smoke moves faster and it takes three cones to get as many pictures as I get with one stick.
2. I shoot in my garage. There are no windows in the garage, so it is completely dark. It is large enough to ventilate better once I open the garage door. I made the mistake of doing it in a bathroom the first time and I had a headache for 24 hours and the shower curtain still smells like smoke. LOL.
3. I shoot from a tripod. I know some others have had success with handholding, but I haven't.
4. I prefocus on an area where the smoke will probably be. This is the most maddening part. I can't tell you the number of times that a cool smoke plume is out of the focus range or goes right out of the frame completely.
5. External flash located on the side, either connected with an extension cord or wireless if you have it. I found that using the flash on the camera itself will throw light on the background and ruin your shots. (MisDan discusses another method in which this is not a problem). In addition, I've created a "snoot" for the flash with "barn doors." You can buy these or create one for yourself out of cardboard (I used a cereal box). The snoot is a square tube that fits over the flash head. I've then cut part of the snoot at the ends to create "barn doors" to direct the light from the flash only onto the area where the smoke is flowing and not on your background or camera lens (use your camera's lens hood as an additional precaution). I've also seen people just take 2 pieces of thick, preferably black card stock and attach them with a rubber band around the left and right sides of the flash head.
6. Black background. I use a 3x3' piece of black felt that I found at Michael's arts and crafts. I found it is the darkest black and absorbs most stray light. Place the incense holder 1 to 2 feet in front of the background to reduce the texture of the cloth from being picked up.
7. Make sure your lens is free from dust or water specks. The flash may still pick those up in your photo and you'll be spending a lot of time just cleaning that crap out of your photo before you even start creating.
8. I use a lens in the range of 12-60 (24-120 35mm equiv. for my camera). I use this lens at a distance of about 6-12 inches from the smoke, which allows me to get a wide capture of a full plume, or a close up of one part (see my previous comment about smoke out of the frame....get used to it, it comes with the territory.
9. Shine a desk lamp up through the smoke, trying to avoid any light hitting the background or the lens. I usually place it lower than the incense tray so that it is shining upward. I discovered this after my first attempts using a flashlight and randomly shooting in the dark...duh.
10 Use a remote trigger for the shots to reduce camera shake. I suppose at shutter speeds of 1/160, this is not absolutely necessary, so don't worry if you don't have a remote trigger.
11 Use manual mode. f11-f16, shutter speed around 1/120-1/250 range. The allowable range will depend on your flash unit.
12. Take a test shot pre-smoke and look at your histogram. It should mostly be in the completely black range. If not, go back and adjust your flash angle, background, desk lamp, or check to make sure your lens is clean.
13. Make the smoke dance. There are different ways to do this, some boring and some embarrassing. I've tried the following:
a. Blow very gently
b. Use a piece of carboard and gently wave it near the smoke
c. Place an object in the base of the smoke. I find a spoon, fork, or pencil work pretty well.
d. gently tap or move the incense tray (this has been my preferred method lately)
e. and now the embarrasing one : ) - Dance around the room a bit. Your body movement will make the air move just enough.
14. Ventilate the room periodically and make sure to douse your incense in water....I don't want anyone burning down their house when the burning incense hits that oil leak on the garage floor. Not that that has happened to me or anything....just in case you were worried.
15. Finally, expect to be disappointed and frustrated alot on your first few outings. My first several tries I had only about a 2% ratio of decent vs. unusable shots. I'm now closer to 50%. If all works out right, you may have one that looks like the one below. Coloring smoke will be the next tutorial.