Renewing his campaign against Hollywood’s rush to convert feature films from 2D to 3D, Jeffrey Katzenberg said Wednesday that he is convinced the format is here to stay, but a spate of conversions this year has made for a bad audience experience.

“Some in Hollywood are ready to seize defeat from the jaws of victory,” the DreamWorks Animation topper declared in a keynote at Variety’s 3D Entertainment Summit.

Katzenberg, speaking at the confab to about 500 film makers, studio execs and technologists, noted that 2009 was a very good year for 3D, bookended by the success of “Monsters vs. Aliens” and “Avatar.” “It was the first year of real 3D viability,” he said “In the worst economy since the Great Depression, the movie business has grown — virtually all due to 3D.”

This year, however, “things got ugly” as more films hit the market that were converted from 2D-to-3D — as opposed to originally conceived and shot in the stereoscopic format. “It’s not acceptable to ask our customers to pay a premium for a bad experience,” he added.

“Nothing will rescue a turkey,” he said. “In fact, 3D has the unique power to turn a bad movie into a painful movie.”

Katzenberg, who has positioned himself as one of Hollywood’s biggest proponents of 3D, launched his vocal campaign against quick 3D conversions in a Q&A with Variety in early April (Daily Variety, April 9). At the time, he was particularly critical of “Clash of the Titans,” which Warner Bros. converted from 2D at the last minute. Its release coincided with the second week’s run of DreamWorks Animation’s “How to Train Your Dragon,” which was conceived and shot in 3D. Both went on to earn serious coin. In worldwide box office, “Clash” earned $467 million, “Dragon” $493 million.

During Wednesday’s summit, held at the Hilton Los Angeles in Universal City, Katzenberg acknowledged that conversion does have a role in transforming TV programming into 3D. He said that titles from DreamWorks’ library would undergo that process.

“It’s a fantastic opportunity for television,” he said. “Conversion holds up much better on the smallscreen.” Katzenberg was adamant, however, that it’s a “failed proposition” when it comes to theatrical release.

He challenged naysayers who consider 3D to be a flash in the pan. Comparisons to the 3D experiment of the ’50s aren’t valid, he said, because all projection in those days was analog; digital projection today makes it viable.

If the business hit a midyear rough patch, with a drop in the percentage of revenues from 3D venues, it was because three major 3D films hit the market at about the same time — “Toy Story 3,” “The Last Airbender” and “Despicable Me” — and there weren’t enough available 3D screens to meet the demand, he said.

“The 3D business is up 160% this year to date. The rest of box office is up 3%,” Katzenberg told Daily Variety. “Plus, six of the 10 biggest movies this year have been in 3D compared to zero two years ago. By the end of the year it will most likely be eight out of 10. What world are we living in that there’s any question about the viability and appeal of 3D?”

While “a small fringe of low-end 3D exploitation films have come and gone, audiences wouldn’t have paid attention to them in 2D, either,” he added.

In addition to bad conversions, Katzenberg cited screen brightness as a concern, noting that 3D glasses darken the projected image. He encouraged rapid adoption of laser projection technology, which can boost the brightness of 3D projection nearly up to the level of 2D (and which can amortize its cost over 18 months via lower power consumption, making exhibitors good green citizens to boot).

More advanced glasses are another way to enhance the consumer 3D experience, said Katzenberg. To that end DreamWorks Animation has been in talks with sunglass maker Oakley to advise on the development of lighter 3D glasses that also eliminate glare and cause less color distortion.

Katzenberg said he sees a bright future for 3D in vidgames. “When people get to see how it enhances the gaming experience, which is already very immersive, it’s going to be a blockbuster.”