Snapshots taken with the world's first hidden camera are set to go on show to give Sydneysiders a glimpse into their city's colonial past.

The Crowd Source exhibition at the State Library of NSW will feature photos from the late 1880s taken by amateur photographer Arthur Syer.

Syer took the pictures to help his cartoonist friend Phil May draw pictures of ordinary people behaving candidly.

He used what was known as a 'detective camera' hidden in a small box to take the pictures, not long after the development of portable handheld cameras.

"The whole idea of a 'snapshot' comes from this time because this was the first time you could actually take a picture very quickly," library historian Margot Riley said.

Like modern smartphones and CCTV today, the use of such cameras sparked debate over the need for tightened privacy laws.

"In the beginning people didn't know and then all of a sudden there started to be a lot of comment in the paper and there were these pesky photographers on the street snapping people's photographs," Ms Riley said.

The exhibition will run from April 4 until August 23.