I would do a mix of a very light even haze plus whatever dust particles you want to float in the air, you could try "effects dirt", which is a sort of powder (Fuller's Earth used to be used until it was deemed unsafe to breathe). You can also try some finely chopped feathers too. Just keep in mind that if you can see particles floating in the air, you want to limit how much of it the actors and crew have to breathe it (the crew can at least wear masks).
It's very hard to create an actual solid shaft of light through dust that is not horrible to breathe, and just faint bits of dust in otherwise clean air is harder to see in wide shots, it's not really a shaft effect. You also need a more projected intense light source to really pick up actual dust in the air well (a Source-4 Leko with a narrow lens works well, as does a Xenon, or a narrow spot ParCan). This is why I suggest that you need a mix of haze and dust, the smoke haze to create a base shaft that you can then float dust particles in.
As for a 5K fresnel, it all depends on what it is competing with. Outside a window at night coming in at a backlit angle, you'd get a nice beam even in full flood, but have it mix with bright ambient daylight and it might not look intense enough, it would be a fainter shaft. On an overcast day, it might be the right amount of light or you may need to spot it in less.
A shaft of light is visible due to the combination of its intensity and the angle relative to the camera coming through something in the air to catch the light, a backlit angle being the most visible.
What's good about powerful projected beam lights or bigger fresnels or open face units is that you get a shaft of parallel rays -- with a spotted-in light you may get a stronger beam but it will be shaped differently than sunlight, it will have a hotter center and the dimmer edge will spread more. If you are trying to create the effect of hard sunlight, it helps to have bigger units farther away so that the beam is sharper and spreads less quickly. Other than a big unit farther away, the only thing similar is a small unit with a lens that projected a focused beam like a Leko-style light. But then you won't have the area of coverage that a big unit further away will create, it won't fill a window edge-to-edge. Now that's not always necessary if you can imagine the sun being cut off from filling the window by some partial obstruction like a tree or other building. This is why it sometimes works to put three or four Lekos with narrow lenses outside a window all coming in at the same angle and direction, so that the multiple beams are parallel. Then it looks like one ray of sunlight being broken up by tree branches or the window frame, etc.
Hi David,
Does a source 4 leko flicker if I shoot high speed? I'm looking at speeds of 100 and 150.
I'm looking to create 'pillars' of light for a music video, so need sharp focused, parallel beams (or as close to that as possible). Considered some stage lights as well, but haven't yet found one that will work with high speed and won't seriously overexpose the actor, should s/he happen to catch the light.
Shafts of Light with 5 KW Fresnels
in Lighting for Film & Video
Posted
Hi David,
Does a source 4 leko flicker if I shoot high speed? I'm looking at speeds of 100 and 150.
I'm looking to create 'pillars' of light for a music video, so need sharp focused, parallel beams (or as close to that as possible). Considered some stage lights as well, but haven't yet found one that will work with high speed and won't seriously overexpose the actor, should s/he happen to catch the light.