They posed grinning beside a bust of George Washington and stood solemnly in front of a portrait of John F. Kennedy. A few even caught President Obama as he walked across the South Lawn to Marine One.
For visitors to the White House, Wednesday proved cause for rejoicing — and a post or two on Instagram — as Michelle Obama announced the end of a 40-year-old ban on photography during public tours. The first lady revealed the news in a video posted early Wednesday in which she literally tore up a sign bearing the rule.
The move, which drew near universal praise, is likely to generate a stream of positive images for the White House and the first family, especially among young people using social media.
Robert Dallek, a presidential historian, said the change would bring greater transparency and openness to the White House, particularly at a time when Republican presidential candidates looking to position themselves as Washington outsiders have criticized the administration for being out of touch.
“They don’t do these things without political considerations,” Mr. Dallek said. “I guess they want to show that they are not hidebound. They’re not strapped down by traditions that limit what goes on.”
The photography ban was originally put in place to address a range of concerns, including the damaging effect of flash photography on artwork and delays in tours as visitors stopped to snap shots and strayed from the tour route.
Advances in camera technology, though, now allow high-quality photos to be taken without a flash.
The White House’s decision was also an acknowledgment of the near impossibility of stopping all visitors from using cellphones to record and widely share personal experiences.
Institutions that still ban photographic equipment, like federal courts, often demand that visitors surrender their cellphones, an increasingly burdensome requirement.
Many tourists who arrived at the White House on Wednesday had not heard about the change in the rules. They found new signs reading “Photography is encouraged” and “Use the hashtag #WhiteHouseTour to share your experience.”