A scientist is embarking on an unusual European trip - to find the places where the idea for the camera was born.

Retired physicist and engineer Roger Smith has an unusual interest.

He is fascinated by the history of the scientific instrument, the camera obscura. And, on Saturday, he is embarking on a tour of Europe to study some of the world's finest specimins.

A camera obscura is a lightproof box, which can be a room, with a pinhole in one side through which an image of outside objects can be projected on to the opposite side.

The 69-year-old hopes to visit 10 countries during his 10 week trip - travelling mainly by rail.

Mr Smith has estimated he will travel 7,000 miles across places as diverse as Romania, Hungary, Spain, France and Italy.

The £6,600 journey is sponsored by the Winston Churchill Memorial Trust, which hands out travel fellowships once a year.

Mr Smith, of Southby Close, Appleton, near Abingdon, said: "I am a physicist and engineer by background, and after I retired I got into the restoration and making of scientific objects - including cameras and camera obscuras.

"Now I make camera obscuras and I am doing this trip to compare them. I have an interest, and I don't know anyone else who has done this.

"Travelling through all of these different countries is a bit like a modern version of the traditional grand tour."

Mr Smith, who worked for school inspector Ofsted shortly before retiring, will take pictures of the camera obscuras - which literally means 'dark room' in Latin.

He plans to share his findings with like-minded enthusiasts when he gets back.

Mr Smith said: "Camera obscuras are of interest to people of artistic backgrounds, and artists used to use them as an optical aid to drawing.

"It will be interesting to have a look at the permanent sites."

Mr Smith was one of 90 people chosen to receive a grant from the trust, out of more than 800 applicants.

The Winston Churchill Memorial Trust offers fellowships to British citizens from all walks of life. The awards give people the chance to increase their knowledge.