BALTIMORE -- Yolanda Vazquez watched a news broadcast on a high-definition television for the first time with mixed emotions.
She was impressed by the way it rendered the anchors in such vivid detail. "It's amazing," she said, "like you're not in 3-D but in 15-D."
But awe gave way to self-conscious jitters once Vazquez, a reporter and anchor at Maryland Public Television, realized that her turn in front of an HD camera was coming.
"You're really under the microscope," she said, "and if you've got a new pimple or a stray hair, it's obvious."
Such is the lot of on-air talent as momentum builds for the most significant technological change in broadcasting since the advent of color TV. Prompted by a federal mandate to switch from analog to digital broadcasting by Feb. 17, 2009, stations around the country are steadily upgrading their equipment to transmit shows in HD.
With at least four times the resolution of traditional equipment, HD cameras and television sets will display Vazquez and other small-screen personalities in images as large, clear and detailed as they are unforgiving.
The change has sparked particular concern among those who perform live. Unlike movies and recorded programs, on which retakes and post-production tweaks can compensate for poor lighting or bad makeup, live shows provide no safety net.
More ominously, in a profession in which personal appearance can be pivotal to success, veteran TV newscasters worry that HDTV could turn a spotlight on imperfections that traditional TV technology overlooked.
"These people are under pressure to look good, and frankly, there aren't a lot of 22-year-old anchors out there, so this really scares them," said Doug McAward, co-founder of Kett Cosmetics, a New York company that specializes in Digital Age makeup.
Older makeup techniques don't work on HDTV because thick layers of powder, pancake and cream show up as clearly as the blemishes they're intended to cover. "If somebody has an imperfection," McAward said, "you want to cover just that imperfection, not coat the entire face to cover it up."
Makeup artists at HD stations with big budgets use airbrushes to apply specially formulated cosmetics. Their makeup contains no silicon or mica because those substances make people look shiny and frosted under the brighter lights that HD requires. Also absent are kaolin clay and other materials that appear to cake in HD.
But even the best makeup can fail under digital scrutiny. During an appearance on "Late Night With Conan O'Brien" in October, CNN host Anderson Cooper said he contemplated plastic surgery after seeing himself in HD.
"You notice things about yourself that you've never noticed before," he told O'Brien. "I learned I have a little fatty deposit under my left eye."
It's the high resolution of digital broadcasts and televisions that provides this detail. Compared with older TV sets, which display 480 lines of resolution, HD sets display 720 or 1,080 lines. The new screen format is also wider, more like a movie screen. This presents another problem -- when viewers watch a standard-format show in widescreen mode, everyone might look fatter than they are.
Nationally, about 65 stations broadcast local news in HD, but the number is expected to grow quickly, said Phillip Swann, the publisher of TVPredictions.com, an HD-focused website.
WUSA in Washington was an early adopter, making the switch in 2005. The HD spotlight worried some on-air personalities.
"There was some angst beforehand as to what we would all look like," said Todd McDermott, who co-anchors the news at 6 p.m. and 11 p.m. "I realized I was never going to be able to hide my 5 o'clock shadow."
In addition to upgrading cameras and transmitters, stations have had to spruce up sets for HD.
George Beneman, vice president for technology at Maryland Public Television, said producers have to redesign sets to fit the widescreen format. Designers also must be careful because HD makes imperfections and cheap materials all too obvious. "You used to be able to get away with things," Beneman said. "But now you can't, because the cameras see in such better detail."
Donna Hamilton, anchor of the 5 p.m. news on WBAL in Baltimore, said she's looking forward to HD but sees positives and negatives about the technology. When viewers see her in person, she said, they often tell her she looks better than on the air. "So I guess if HD makes me look more like I do in real life, that's a good thing," she said.
She said the hosts of NBC's "Today" show -- Matt Lauer, Al Roker, Ann Curry and Meredith Vieira -- seem more real in the format. "I look at them, and they look good," she said. "Of course, they have the best -- the best lighting, the best makeup."
But Hamilton and other anchors acknowledge that HD might accentuate an industry tendency to favor young, attractive talent over veteran journalists.