I need to shoot a direct car light at night. need advice
 

Hi, I need to shoot a direct car light at night (I am using HD100U camcorder) and am wondering what filter should I use? ( I have a matte-box that uses 4X4 filters). Reason being that in general when one shoots car lights they tend to "blow-up" into star-shapes, they blur images, etc. I need the car lights to be vere "calm", diffused, so they are contained in their car light frames.

Are the filters best way to go? There are glasss filters and other types of filters (rasin, etc), which ones are better/should I use for this particular purpose?

Someone suggested using dulling spray, how valid is that?

I've been mostly shooting without filter, so as to have more latitiude in post-production, but I came to conclusion that filters produce better looking images, so I am thinking to use them more. I am wondering if someone can recommend a good overall books (or maybe several books) that would guide me through the filters, types, usage, etc.


Thanks a lot.

Double Post deleted. * * *

Car headlights are so much brighter than most other things in a scene that they are bound to bloom unless you are lighting your scene so brightly that they are relatively dim compared to your background. I'm guessing your only choice is to put neutral density (ND) filters over the headlights themselves. Since you won't need much, I would get a bit of each strength or multiple layers of the weaker stuff so you can get exactly the right f-stop value from the lights. The dulling spray is not a bad idea and you could also use some light diffusion gel for effect. Don't forget that you can also play with the color of the car headlights. Standard headlights will be around 3000K, but HID lights will be more like daylight.

Don't do anything to car headlights that are going to be driving on the street with any other traffic!

I'm no filter expert, but I'm wondering if a polarizer would help? I would guess that it would reduce the star/bloom to a single line, which you could set as horizontal or vertical - whichever is best. You could then apply a directional filter in post across the line to minimize it.

It's jsut an idea. Maybe somebody with more expereince with polarizers would know.

BTW, we shot some stuff on a greenscreen recently, and our polarizer was like magic. We were able to dial out a lot of the green bounce off of glass and other reflective objects. It's a nice thing to have in your tool kit, regardless of whether it works on headlights or not.

Another idea: shoot day for night and the headlights won't be so bright.

A polarizer won't work with direct light so the headlights won't be effected. It only works on light bounced off a non-metallic surface like water, glass, or leaves.

I don't like day-for-night. It almost never is convincing. Light your set sufficiently and the headlights will be fine with a bit of gel.

There is no camera filter that can have a significant effect in matching different light levels in a scene except for the polarizer on polarised light. Other filters are not very selective in which light they reduce unless you use a color filter that filters out specific colors but would tint your video.

dulling spray works slightly ..
i find using black Studio hair spray ( washes off with water) works very good .
you spray it on several times ( each very lightly ) - you don't want it to be solid color - just alot of mist drops ...

here's a link to 3 scenes with headlight into lens ..

http://briefcase.yahoo.com/bc/jkapla...ase.yahoo.com/

1) fogger used in scene ... headlight have light dulling spray & a little black hairspray ... camera double fog filter

2) wide shot mountain road - evening magic hour ( sky kept out of shot) no filter on camera ... when scene moves to park cars = different location night ( community center parking lot - lit so backgorund is blackness) .. 2 shot cars= both cars have black hair spray on headlights -low con filter on camera .... cut to police car - headlights black hairspray cleaned, now they have light dulling spray .. police car spot light is clean - camera has double fog filter ...

3) car backs into driveway - headlights have very heavy black hair spray .. camera low con filter

Since headlights are only about 60 watt halogens, you're describing the smear that happens because of the extreme contrast with the "dark". Clearly, the same lights in daylight won't smear. I happen to think shooting day for night isn't a bad solution. The HD100 is still subject to the limits of 1/3rd" video chips.

The link Don posted did not work for me, but I like his ideas. Evening-for-night with dimmed lights sounds fine assuming the sky is avoided or keyed out. I had not thought of black spray, but it sounds interesting. I even have some of that, so I am going to try it out. Thanks.

Ya know, it's not really that hard to do outdoor night lighting. A few big fluorescent lights can do it all off an inverter or a tiny generator. With tall light stands (or poles/ladders) and an electric outlet, it isn't that hard. Just use mostly backlight or side lighting and make sure there is some scenery lit in the background.

you might have to click on the link 2-4 different times ( sometimes it goes to can't be displayed page) ??? got me - it's a yahoo thing

http://briefcase.yahoo.com/bc/jkapla...lights&.view=l

Polarizers
 

Polarizers will work with "direct" light, if you use them on both the source and the lens. Cover the headlights with pieces of polarizing plastic cut to size, then put a polarizing filter on your camera lens. You can then rotate the polarizer on the camera to "dial in" the brightness that you want, over quite a range. Also nice because it doesn't noticiably affect color temperature.

Dan,

That's brilliant! Fully adjustable headlinghts. Nice!

BTW, that's kind of how LCDs work. They have a front and a back polarizer at right angles to one another. The liquid crystals are able to twist the polarization of the light. When there's no twist, no light is passed. Apply a charge to the liquid crystals, the light is twisted 90 degrees, and the backlight passes on through to the viewer.

Recently heard a little gaff tape in an x across the center of the headlight to dampen the direct light. It'll bloom around the gaff to hide it still :)