There is something about product photography, I just love it. Shooting products is so technical to start with, movements in the millimeters can completely change the resulting image. When you mix in your full creative muscle the resulting photographs can be astounding. Here is one of my current favorites, complete with how I did it.
First off this image was extremely difficult to pull off. This is taken in one shot, no compositing here. To create the fire effect, I used real fire, a sparkler actually.
Now to the Fire Part
I started by placing the sparkler behind the product. Then I needed complete darkness. Camera mounted on a tripod, and two studio strobes placed at 45 degree angle facing the product. White seemless paper background (caution this could be flammable).
The camera needs to be set to a longer exposure time to let the fire do it's work. I should mention that because I did this on white, I had to absolutely nail the exposure to get this to work. Both the aperture, shutter times and intensity of my strobes had to perfect to create this effect. I would recomend trying this out on grey if your less experienced. Grey will transmit colour a lot better and is way more forgiving.
I went with 2.5 seconds at f5.6. The smaller the aperture the thinner the streaks of light will be. Too large and the fire becomes a blob and we also get in to focus problems. f5.6 gave me the exact result I was looking for.
I'm using pocket wizards to trigger my lights to trigger them remotely. Now here is the most important part. Your camera needs to be set to rear curtain flash synch. What happens is this: the camera will release the shutter to take the exposure and at a fraction of a second before it closes the strobes will fire.
Place sparkler product etc. Camera on tripod.
In complete darkness, light sparkler.
Fire camera when flame is in desired position in frame
Strobes will fire when shutter closes.
Put out any fires you have started.
When I post these instructions I ask that all readers don't directly copy the image. By all means incorporate these steps to create something new and original that is your own.