Capturing vapour or faint steam

Question

I was trying to capture a scene that was in a dark area with a bright background. There was faint steam that I wanted to be the focus of the picture. I tried first by having a very large aperture and quick shutter speed to capture the vapour as still as possible, but it yielded no results. I tried three other setups, including sensitivity increase by 4x, but I just could not capture the steam.

It later occurred to me trying to increase the sensitivity much more, but the scene was unavailable.

What is generally the best setup to capture steam or vapor in such a situation?

I am working with a Canon Rebel T2i.

Answer 1

Without seeing the scene it's hard to know with absolute certainty what you could have done differently, but for me the first 'red flag' in your question was your statement that there was a bright background. That doesn't make it impossible to get good steam, but it makes it a lot more difficult... Especially in uncontrolled lighting situations like the one you seem to be describing and even more-so if the steam was faint as you describe. The other thing to note is that on a scale of 'easy' to 'impossible,' photographing steam is a moderately difficult assignment, even under perfectly controlled studio conditions.

My thoughts would be these:

1. Change the camera position in order to get a dark background. This one is tough to work around... steam is light and wispy with no defined edges, thus it is very easy for it to get lost with a bright background.
2. Use a fill flash positioned somewhere between 90 and 135 degrees perpendicular to the camera (It's a variable. Your light won't necessarily be in the same position shoot-to-shoot... Depending on how active the steam is, it may not even be in the same position shot-to-shot). This should brighten up the steam considerably with the goal being to separate it from the background.
3. Shoot a ton of pictures. Steam is one of those things that you end up taking lot of frames and hoping you get a couple that are great... There's certainly an element of luck or 'happy accidents' that play a part in capturing great shots of steam.

If you're looking for some practice, I'd recommend buying some incense sticks and working on getting great shots of that... You'll walk away from that practice with a much better idea of where you're going to need to place your lights in order to give yourself the best chance for getting a few 'winners.'

Answer 2

Lighting dust, haze, smoke and mist (water vapour/steam technically refer to the gaseous state of water and is thus invisible, like air) is all a matter of contrast.

As Jay states the problem lies with the fact the background is brighter than your subject. Here's an example of the opposite effect where the mist emerging from a chimney at York Minster catches direct sunlight and is seen much brighter than the surrounflding walls (which are in shadow) and even the blue sky!

If you can't engineer it so the the sun strikes your mist and not the background then a good alternative is to use an auxiliary flash.

The angle of the light is not overly important as mist is diffuse and so reflects light equally in all directions (so it will appear the same regardless of the lighting angle). The key is to get the light as close to the mist as possible, light diminishes in intensity with the square of the distance. This means that if your flash is 1 meter from the mist and 10 meters from the background the mist will receive 100 times the light!

It is important to angle the flash so that it doesn't shine down the lens, and not pointing it directly at the background will help contrast a little. You ought to be able to get a decent contrast with the onboard flash even if it is pointing towards the background if you shoot in twilight and use the fastest shutter possible (usually 1/250)