We've already mentioned lit windows and flashlights, but there are as many other practicals (light sources you can see in the shot) as your ingenuity can supply.

Streetlights are great for atmosphere. To simulate the effect, aim a spotlight almost straight down on your subjects, then fill just enough with blue-gelled light to prevent black eye sockets and Hitler-moustache nose shadows.

Car headlights can be treated like flashlights: establish the light source with real headlights, then light closer shots with key lights placed about three feet off the deck so they aim slightly upward. In many cases, actual car lights are bright enough to function as movie lights, but don't use the yucky bluish types found on some boyz import cars. The whole idea is to contrast the blue ambience with headlights of honest white.

Room practicals can be hard to balance because you can't move them closer or further away, at least not when they're in the shot. Dimmers work well, down to maybe 75-percent of full power. After that, the light is too yellow to look real.

Of course, you do want that yellow/orange look for firelight. To achieve that, follow a slightly different plan:

• Use a straight halogen lamp to set the white balance (preferably by bouncing its light off a white card and into the lens).
• Gel the ambient light lamps blue, as usual.
• Either run the incandescent firelight down on dimmer or gel it orange. I prefer the dimmer because you can make the fire flicker by wiggling the control.
• Add a "hula skirt" of newspaper strips attached to a horizontal stick and waved in front of the light and you've got warm firelight on your subjects with cool blue shadows behind them.

Contributing Editor Jim Stinson is the author of the book, Video Communication and Production.

Night scenes are generally darker and have more contrast than usual and this effect is easy to enhance with your editing software. Don't work on individual shots, but on fully edited night scenes. When you've edited a day-for-night sequence:

• Darken it until it looks more like night.
• Increase the contrast until shadows and dark areas start to lose detail.
• Re-adjust the brightness and contrast until you like the effect.

You can also adjust the overall color cast, especially if you don't have halogen lights adding white light to the scene.

Finally, if you must have a wide shot with sky, try selective color replacement. First, temporarily remove the overall blue cast, and then replace the blue of the sky with black. Finally, re-tint the sequence so that halogen lights are white and the rest has a bluish cast. This can work if you have sharp boundaries between the sky and everything else, but will be very difficult to pull off with fuzzy boundaries, such as the sky seen through trees.