As legend (and “Swingers”) has it, noted perfectionist Martin Scorsese spent three days setting up “Goodfellas’ ” signature moment — an unbroken three-minute shot that takes the camera from the street, through the bowels of the Copacabana, to Henny Youngman onstage inside, and reliably sends most cineastes into a heightened state of stupefaction.

For “Planet Earth” producer Huw Cordey, who spent 10 straight days living in a cave to film a single six-minute sequence, that’s amateur night.

“It was like mountaineering — underground, in the dark,” Cordey says of the shoot that took him deep into New Mexico’s Lechuguilla cave. “It took us eight hours just to get to base camp, passing through these incredibly narrow squeezes in the rock. At one point the guide that was with us said, ‘If anybody has an accident now, we’ll have to dynamite the cave to get you out.’ ”

Such is the unusual dedication from the crew that — along with technical innovation and the sheer amount of time invested (five years) — distinguishes the 11-part natural-history series, a co-production of the BBC and the Discovery Channel.

Series producer Alastair Fothergill, who also produced “Planet Earth’s” stylistic antecedent “Blue Planet” for the BBC, made high production values a priority.

“It was an interesting marriage between Hollywood and natural-history filmmaking,” he says, “but that was very much part of the vision at the beginning. I wanted to give it a cinematic feel.”

Consequently, the series strikes cinematic tones and moods rarely evoked by nature programming, ranging from the balletic — lushly photographed birds of paradise, iridescent jungle frogs diving from trees in slow motion — to the genuinely horrifying, such as verite-style handheld footage of a chimpanzee colony raiding and massacring a smaller rival group.

The entire series was shot in high-definition, and it adopted feature-film techniques and equipment new to natural-history filmmaking — most notably the Cineflex heligimble camera system, used for aerial shooting.

Michael Kelem, an aerial d.p. more acclimated to Bruckheimer actioners than nature shoots, was recruited to helm the chopper-mounted camera, and captured extensive bird’s-eye footage of rarely spotted African hunting dogs on the attack in Namibia. A newcomer to wildlife filming, Kelem quickly came to appreciate the difficulty of the job.

“Looking at it from the air was very difficult, because (the dogs) could be anywhere in this huge area,” he says, “and trying to track them, visually, from 1,500 feet was really hard because they blend into the scenery. And then finding them with the camera was extremely difficult because once you lock onto an animal, you stay with it for the duration — like two hours — and if you lose track, then you’re back to square one.”

As Fothergill recalls, “Michael was just exhausted. Keeping everything in focus was ripping the eyeballs out of his brain.”

Other innovations involved both state-of-the-art technology — an ultra-high-speed, direct-to-disk camera was used to capture an airborne shark attack — and such low-fi ingenuity as the improvised rigging for a long tracking shot all the way up the world’s tallest tree. The shot was achieved by slowly pulling the camera — stabilized by bicycle wheels — up a series of cables from bottom to top.

“I deliberately wanted that,” Fothergill says, “because the shot just goes on and on, and all the while you think the tree can’t possibly get any taller.”

The tree shot is one of many in the series that stretches to Scorsesean length. While some nature programs are forced to scrap together short bits and pieces filmed at different times, “Planet Earth’s” cameras tend to linger. As Fothergill acknowledges, “Your average 50-minute film has 700 cuts. ‘Planet Earth’ had between 300 and 350, so it’s very slow.”

Cordey singles out the HD quality as his primary reason for letting the camera run: “You had so much detail in each shot that you didn’t want to cut it.” And Discovery Channel general manager Jane Root adds that “Planet Earth’s” long takes are “part of its distinctiveness,” as well as a return to the steady-handed aesthetics of older natural-history programs.

“It was traditional documentarymaking, but done with a modern twist in terms of new technology,” she says.

For Fothergill, it’s all part of the series’ philosophy, which he sums up thusly: “When you have confidence in the natural world and you photograph it in the right way, then you don’t need any trick photography, or CGI, or presenters strangling crocodiles.

“It’s reassuring to see that there still is a natural world out there.”

See video: One of the challenges to the series “Planet Earth,” explains Discovery Channel G.M. Jane Root, is the patience and dedication of getting “THE” shot.