GIANT leaps forward in filming techniques mean viewers today can get closer than ever before to the natural world and all its wonders.

Spy in the Ocean (BBC1, Sunday, 7pm) takes the experience to the next level. Using undersea robots made to resemble the creatures they are filming, the programme gives viewers a licence to snoop, and the results are incredible.

David Tennant narrates as the first of four episodes zips across continents in search of its subjects. We begin with, what else, whales. A robot the size of a newborn whale approaches a pod. A female goes to explore. She nudges the “youngster” with infinite gentleness and tries to communicate with it. The stranger is allowed to stick around.

From there it is on to the coral reefs of Indonesia, home to the coconut octopus, a creature with eight tentacles, a brain in each one. The coconut octopus walks on two tentacles, as does the spy octopus sent to make contact. Before you know it the two are working together to fight off ravenous shark.

In another filming first we see macaques swimming underwater (they do a sort of doggy paddle). Like cheeky monkeys everywhere the younger ones like to cannonball into the water. Watching and filming is the episode’s cutest robot, a spy macaque. Well, it is the cutest till we go to the Caribbean to see the famous swimming pigs. Fantastic from start to finish, and a programme for all ages.

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All the Beauty and the Bloodshed (BBC2, Sunday 10pm) is an Oscar-nominated portrait of Nan Goldin. Director Laura Poitras introduces us to two Goldins. The first is Goldin the artist, whose photographs, like those of Diane Arbus, celebrate outsiders. The second is the activist who took on the pharmaceutical giants over the opioid crisis, of which Goldin was herself a victim.

She became addicted to the pain-killing medication after being prescribed it post-surgery. Although she survived, many others did not. Some of the families and friends who lost loved ones are seen joining Goldin on protests. The film opens with one such event at the Met in New York, with another at the Guggenheim. Goldin’s artistic life has been a walk on the wild side and then some. To then lead a campaign that could have cost her everything is a remarkable achievement.

The same word comes to mind when watching Vicky McClure: My Grandad's War (STV, Monday, 9pm). Ralph McClure, 97, lives round the corner in Nottingham from his granddaughter Vicky, the Line of Duty star. They are each other’s biggest fans. “He’s just a lovely man,” says Vicky. “She’s remarkable, isn’t she,” counters grandad The family knew in general terms that Ralph had taken part in D-Day but for a long time he did not speak about the experience. Someone, learning of this, has thought “What a great idea for a film” and they were right. Between them, and with the help of a historian, grandad and granddaughter take the viewer back to that world-changing day in 1944.

At one point, McClure gets into the sea at Normandy in a soldier’s uniform of the time. The weight of the clothes and kitbag threaten to drag her under but she makes it to the beach, exhausted. Ralph recalls his landing after a 22-hour journey from England. He had no sooner put a foot on the ladder taking him off the boat than German snipers were firing at him.

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From the sea front the pair travel to the British Normandy Memorial, inscribed with the names of the 22,442 servicemen and women who died on D-Day and during the Battle of Normandy. Everywhere Ralph goes he finds people thanking him and wanting to shake his hand. “We were just doing a job,” he says.

Take it from me that Greggs: Secrets of their Best Bakes (Channel 5, Wednesday, 8pm) is not one to watch on an empty stomach. Mine went from growling like a kitten to roaring like a lion by the hour’s end.

Food critic Grace Dent is your guide to the shop that began with one man on his bike in the 1930s and grew into a brand that sells five sausage rolls every second of every day.

Food scientists and chefs are brought in to explain and try to reproduce the Greggs magic (spoiler alert: secrets remain intact).

Better still is the trip to Greggs HQ in Newcastle and the development lab where staff are dreaming up ever more tempting treats, including warm yum yums with dipping sauces. Finally, Dent has a sit-down with the CEO of this billion pound venture - one Roisin Currie, Glaswegian and graduate in business law and business administration at Strathclyde University.

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Sure it is all one big advert for Greggs, but the brand is a copper-bottomed, home-grown success story, and we could all do with more of those.