The bow of “Pirates of the Caribbean: On Stranger Tides” had the lowest percentage of domestic 3D grosses of any non-family film since “Avatar” — below even the heavily panned 3D conversion “Clash of the Titans.” It was just 46%.

Does that mean it’s time to question the durability of 3D with U.S. auds? Not necessarily.

“Clash” rode a wave of interest in the format following “Avatar” but battled negative word of mouth for its rushed conversion, tallying 52% of its opening gross from 3D. “Stranger Tides” debuted Stateside with $90 million this weekend, but 37% of that was in 3D, with an additional 9% from Imax engagements, according to Disney stats released Monday.

“Clash” bowed in fewer 3D locations, with 1,602 (or 42% of the total location count), compared to “Stranger Tides,” which opened at 2,747 3D engagements (66% of its total locations).

While opening 3D shares have wildly fluctuated since “Clash” — ranging from 95% for “Piranha 3D” to 50% for “Gulliver’s Travels” — it seems audiences haven’t been embracing the format to the extent they did when “Avatar” set the 3D gold standard.

B.O. pundits will tell you that 3D reception hinges on whether auds embrace particular pics as a 3D event. That makes sense — mostly.

This weekend, the worldwide haul for Disney’s four “Pirates” films crossed $3 billion, making the series one of Hollywood’s most successful franchises. But because “Stranger Tides” is the first “Pirates” pic released in 3D, bizzers questioned whether auds, already comfortable with Johnny Depp in two dimensions, felt the need to shell out extra cash for the 3D premium. (With “Thor,” Paramount introduced a new potential franchise in the 3D format, and 60% of the opening-weekend aud picked the stereoscopic version.)

The familiar property logic may also impact Warner Bros.’ 3D version of the “Harry Potter” finale, which will also be the first pic in the franchise converted to the format and could have auds pondering the added value of 3D for a series that’s been a big winner in 2D.

But that’s why Disney offered auds the option of seeing “Stranger Tides” in 3D or 2D, Dave Hollis, studio’s exec VP of motion pictures sales and distribution, told Variety. “Giving consumers the choice is very important in helping drive global box office,” he said. “There are some consumers who will gravitate toward 3D, and there are those that won’t.”

Auds are also growing savvier about the difference between conversions and pics actually shot in 3D (“Stranger Tides” was shot in digital 3D), as evidenced by the growing use of the latter as a marketing point (“Drive Angry” was among the first to use “shot in 3D” in its marketing materials).

Not surprisingly, “Stranger Tides” fared better in 3D with overseas auds, with 66% of the film’s record-setting $260.4 million international debut coming from 3D. Moviegoers outside the U.S. have embraced the format more consistently — though that acceptance also varies market-to-market. In Russia, for instance, the format still plays boffo. But Latin American auds, who are more family-oriented than in most other territories, have yet to show much enthusiasm for 3D.

B.O. observers insist that it’s unlikely more audiences would have shown up to “Stranger Tides” had the film been released at more 2D runs; those who wanted to see the film opening weekend did, regardless of the format.

Oddly enough, those who did see “Stranger Tides” in 3D said they liked it more: 94% of 3D screenings scored a “highly favorable” rating vs. 81% for 2D, according to opening-weekend exit polls. That should bode well for the 3D version in repeat frames.