exterior urban lighting at night

Nate Schenker · April 29, 2008

So I need some advice about this lighting scenario:

I'm shooting on a rooftop at night in the Boston area on a very limited budget. I want to give a blue moonlight effect, very stylized (not realism).

I have considered several options and talked to many people. My initial thought was to use an HMI, but after discussing this many people have frowned upon this option.

So, for a cheap option to cover the most area with a sort of blueish moonlight, here's what I am looking at:

Several (6-8) 1kW lights with 1/2 or 1/4 CTB blasted at a distance through an 8'x8' butterfly with diffusion material to unify the light sources and give them maximum spread to cover the biggest amount of area. As far as materials go, this is where a big question exists: after much research I have come to the conclusion that if I go this route, either grid cloth or half/full soft frost would be best for using multiple light sources and wide spread.

Does anyone have any suggestions as far as these ideas go? Any potential problems? Keep in mind I'm on a very limited (student) budget.

Oh, and I'm shooting on digital HD 1080/24p.

Any help would be huge! Thanks!

Ralph Keyser · April 29, 2008

So what was the concern about an HMI source? You're going through diffusion anyway, so that will give you a softer light.

Assuming you are using house power, I would think that it would be much easier to find enough circuits for an HMI or two than 6-8 1K tungsten lights.

Of course, if you have a bunch of tungsten and no HMIs and budget is an issue...

Nate Schenker · April 30, 2008

Hey Ralph, thanks for your reply...

Actually there's a good chance I'll have a 6500W Honda Genny on set, so 6 1k's are possible. As far as HMI's go, all I could do would be a 1200W flick-free. So would you recommend the 1k's geled or HMI?

Also, as far as diffusion material goes..

Michael Nash · April 30, 2008

An HMI is MUCH more power efficient than gelled tungsten, if you're looking for blue moonlight. 1/4 CTB on tungsten is pretty mild if you're going for a "stylized" look. 1/2 blue is pretty common for a "realistic" blue moonlight effect. But if all you want is 1/4 CTB then tungsten may actually be better.

That Honda putt-putt is a noisy bugger though, so I hope you're not recording sound.

James Brown · April 30, 2008

Hi,

If all you want is a moonlight wash a 1.2 par gelled with say 1/4 Warmth will give you a stylistic blue moonlight and is a lot less cumbersome that 6 1k's. Less lights means less things to go wrong, less gels, less stands, less shotbags and so on.

For the spread i wouldn't go anything smaller than and 8x8. Is a 2.5 Par out of the budget?

James

Drew Hoffman · May 1, 2008

I would definitely consider heavier blue, especially if you're going for a stylized look. Shoot some tests, if you can. Especially on a limited budget, a little extra money up front on testing will help you pick out exactly the look you want and it's better than going through production and realizing it isn't working in post.

Mike Williamson · May 1, 2008

Just to add one more opinion, I'd suggest getting two Joker 800 HMI's, plugging them into house power, and putting them through an 8' x 8' frame of maybe Light Grid. You can gel them with whatever strength of CTO you want to partially correct them, and you may want to add some diffusion on the doors before you hit the larger frame. I recommend Jokers because they're fairly powerful lights and they'll run off of house power, I believe they're more powerful than the average 1.2K HMI PAR.

David Auner aac · May 1, 2008

Does anyone have any suggestions as far as these ideas go? Any potential problems? Keep in mind I'm on a very limited (student) budget.

Oh, and I'm shooting on digital HD 1080/24p.

Instead of gelling your lights you could also alter the white balance of your camera. Balance it around 2500K and the 3200K tungsten will look blue. Season to taste!

Cheers, Dave

Kiarash Sadigh · May 1, 2008

Yes...if you ended up going with your Tung plot (which I wouldn't recommend) then leave them naked (more output and punch) and CTO your foreground lights..... then white balance to the CTOed fixtures in the FG and your BG or moonlight will naturally fall into blueness.

Also, in case you go HMI, you can bounce as oppose to shoot-through...your light will more likely be evenly spread out....and sometimes it's easier to rig a bounce four stories high than a light.

good luck!

Ralph Keyser · May 1, 2008

As far as the diffusion material goes, it really depends on the scene. Basically, as you know, you are trading softness of the light against how many photons you get (lumens, footcandles, etc) as you go from heavy diffusion to light. What function is the moonlight serving in this shot? Are you using any other lights in this scene?

I'd be inclined to pick the 1.2K HMI as well (especially if it's a PAR) over the 6 1Ks for all the reasons mentioned here. Oh, and Michael's absolutely right about the noise from those Honda 6500's.