The gallery was opened outside regular hours on Wednesday night and Thursday morning to two groups of 50 people who visited the exhibition with their tan lines on display.

Benjamin Law who was one of the participants in the first group, said he was nervous going in and didn't know what to expect.

"We all gathered in a room and we were given a 20 minute spiel about safety, protocol and hygiene," he said.

"We all disrobed at exactly the same time and put our clothes in like a postpack bag that you get at the post office. And we labelled them and our clothes were taken away."

Law said that initially, only those who came together were chatting to each other, but once the group got naked, everything changed.

"As soon as the clothes came off everyone got very social and I think it has to do with the fact that we were forced to make eye contact – because you don't want to look anywhere else. Because everyone was in this strange, funny, completely surreal experience people bonded really quickly," he said.

"What was funny was all the staff and security remained clothed so talking to a lot of them, they felt far more awkward than they imagined we were feeling because we were the majority."

Having now experienced the James Turrell exhibit both clothed and naked, Law said it definitely added an extra element to the exhibition.

"As we were experiencing some of the art and you look around and see people in their naked forms, they do look like they're part of the art.

"The art is a recurring motif in the art history and there was something sculptural about the way some of the people looked in the works."

Melbourne-based artist Stuart Ringholt, who has previously held other nude gallery tours at the Museum of Contemporary Art in Sydney and MONA in Tasmania, led the tours.

"The Canberra crowds stand up extremely well [compared to other cities] – you have a very happy bunch here," said Ringholt.

"There were people doing cartwheels in the gallery this morning and dancing so they were very cheerful."

While there was a mix of genders and ages, Ringholt said the Canberra crowd was younger on average than elsewhere, and a lot of people travelled to take part.

"One young girl had driven from Sydney and two more young women had driven from Melbourne and they were driving back last night for work this morning.

"That's quite incredible – they were obviously really keen to experience the Turrell exhibition without clothes. It has been an experiment and we were pleasantly surprised."

While Ringholt said the demand is definitely there for more naked tours, a national gallery spokesperson said: "These tours have been a great success and very popular but we have no immediate plans to host another tour despite many requests".

The naked tours are the first of their kind for the gallery, and the third and final tour will go through the exhibit Thursday night at 7.30pm.