The Christie's auction of magic lanterns, optical toys and cameras - dubbed "optical illusions and elusive opticals" - in London on May 11th, includes rare precinema viewing devices. A mutoscope - one of the pre-cinema devices - is expected to fetch between £8,000 sterling (€12,880) and £12,000. The mutoscope (lot 8) is like a "what the doctor saw" machine, says Mr Nicholas Hawkins, specialist in the camera department. "It's like you'd see in old cartoons - people looking through these machines and turning the handles - like an animated peep show with early film in it."

Made by a German manufacturer - although the catalogue says it's British - it has a rare art noveau-style design on the side. When you turn the handle and look through a pair of lenses, you see a Charlie Chaplin film as though it's in motion.

Another highlight is a praxinoscope, another early motion-picture device (lot 11). With a praxinoscope, "you look at a central prism composed of mirrors and you see a picture as though it's moving in the mirrors", says Mr Hawkins. Estimated at £4,000 to £6,000, it's a rare praxinoscope, being hot-air driven rather than hand-turned. You could see a short film on a mutoscope, but a praxinoscope was usually for cartoons such as children's drawings. You might have a man jumping over a hoop, or a cat on a chimney. Mutoscopes were used as pier-side entertainment for adults. Praxinoscopes were made by toymakers but they were also of interest to people keen to develop motion pictures, says Mr Hawkins. A third highlight is a triunial lantern (lot 101) - a magic lantern with three lenses - estimated at £5,000 to £7,000. Magic lanterns were early projectors for painted, mounted slides, usually used for Victorian parlour entertainment. The triunial lantern "would originally have been used by a touring lantern showman. The effect of three lenses was that you could switch slides very quickly and easily. If you had, for instance, a series of slides comprising five images, you could switch them much more quickly than if you just had a lantern with one lens on it."

Spy cameras in the auction include a 1950s German ABC wristwatch camera (lot 285) estimated at £600 to £800. "It looks to all effects like a watch but it's really a camera that you wear around your wrist." However, whether it was used for espionage is doubtful as this kind could be bought commercially. But there are Russian spy cameras in the auction, including a bag camera (lot 286; estimate: £800 to £1,200) and an attache-case camera (lot 288; estimate: £1,500 to £2,000), which Mr Hawkins believes were used by the KGB.

Things you might have at home that could be offered at an auction such as this include good-quality 35-millimetre cameras. Novelty cameras can also do very well, such as concealed cameras and miniature cameras like ring cameras. "They're not all valuable but they are all in the collectible category. Other things that some people may still have are the early lanterns - children's lanterns made by various German toy manufacturers, usually tinplate and quite brightly coloured and decorative."

Hand-painted slides and stereoscope material (viewing two images in 3D), which were produced extensively in the late 19th and early 20th centuries, can also be valuable.

jmarms@irish-times.ie