In Hollywood, Nature’s Rain Is Second Best : Movies: Real downpours can come at the wrong time or look phony on film. So, special-effects teams get the call if directors want things wet.

In a town where bottled water is preferred to tap, is it any wonder that real rain is considered just not good enough for reel rain?

In other words, before Hollywood shoots any rain scenes, it has to wait until it stops raining.

“The best rain is when you create it yourself,” said Bill Baratkowski, executive producer at Coppos Films, a local company that makes commercials. “You can backlight it and do all the things that you want to do. When it is raining, it doesn’t necessarily look like rain on film.”

So this week’s deluge did not exactly have Tinseltown singing in the rain.

Poor Mel Gibson. Not one but two of his projects were affected by the downpour.

Warner Bros.’ “Lethal Weapon III,” starring Gibson, had completed its principal scenes by the time the storms hit, but still had an action car chase sequence on freeways near Los Angeles International Airport left to shoot this week. Now producers have shut down until next week--adding about $60,000 to the film’s $37-million budget.

“Rain--in L.A.?” lamented Steve Perry, the movie’s second unit producer. “Production is down all over town.”

Producers for another Gibson picture, the upcoming romantic adventure “The Rest of Daniel,” decided to buck Hollywood tradition and go with real rain. They juggled their shooting schedule to shoot exterior rain scenes in Claremont earlier this week.

Things went well enough at first. Then the rain started to let up a little. In order to maintain a consistent downpour for the cameras, “we had to turn on our rainmakers,” said a spokeswoman for the film. Chastened by the brush with nature, the production is shooting interiors until it stops raining.

Jeff Peters, supervising producer of the NBC drama series “Matlock,” said rain also spoiled plans to shoot an outdoor scene in which gang members set a house on fire--”which is very difficult to do in five inches of rain.”

The weather even scuttled one interior session this week: a taping of The Tonight Show at NBC’s Burbank headquarters was canceled because rain prevented host Johnny Carson from driving in from his home in Malibu.

Coppos Films went ahead and shot a 30-second commercial spot for the luxury automobile Infiniti despite the rain during the past few days. “We were doing it in between the drops--literally,” Baratkowski said. “We were shooting at a mansion in Beverly Hills, and when it cleared, we jumped outside, and shot outside.”

He said an overcast sky and wet roads are preferable when shooting a car commercial, because too much sun causes glare on shiny paint jobs, and slick, wet roads provide an appropriately sexy look. For that reason, he said, many auto commercials are shot in the damp Pacific Northwest. But actual rain complicates things. “There are just so many logistical things . . . it drives you crazy,” he said.

Peters, of “Matlock,” agreed that technology is better than nature when it comes to television. “When we need rain, we make rain,” he said. “We have these things they call rainbirds--big towers that spew rain, and turn it on and off when you need it.”

Movie rain and movie snow are created by special-effects companies such as Image Engineering Inc. of Burbank, which worked on “The Rest of Daniel” this week, and Dream Quest Images of Simi Valley.

“When studios need a mudslide, they come to Dream Quest and say: ‘Build us a mudslide,’ ” said Mark Galvin, Dream Quest’s head of production. “We create those natural disasters for them. . . . That way, everybody lives happily ever after.”