The Ilex was sold by A.C. Jackson's Ilex Camera works, it was fitted to some of their magazine cameras and was also sold separately. It is based on H.P. Tattersall's patent of 1900.

With the shutter set and the end of the setting rod at the lower right both blades are at the bottom of the shutter and the two springs attached to the blades are tensioned. The top blade is connected to the piston in the delay cylinder on the left, its travel being controlled by the piston. When the release catch is depressed the top blade is pulled up by its spring at a rate determined by the delay cylinder. On reaching the end of its travel the top blade rocks a lever lying next to the delay cylinder, this frees the second blade.

The image far right shows the shutter set.