The Focal Plane Imperial was introduced in 1907, it was based on the Triple Extension Imperial but included a built-in focal-plane shutter in addition to a roller-blind placed behind the lens. There were a few variations:

• When introduced the Focal Plane was available in half-plate size only, the focal-plane shutter had a single slit and gave speeds between 1/100 - 1/500 by varying the spring tension.
• The 1908 model had three slits: one, full width, for focusing; a second of around 1 ½" for slower speeds and a narrow slit for fast speeds. The speed range is given as 1/20 - 1/1000.
• The 1909 model had speeds of 1/25 - 1/1000 (this may have in effect been the same as the 1908 model).
• In 1914 a whole-plate size was listed.

Other variation followed the ordinary Triple Extension Imperial specification, notably the 'Three-Bar Front' introduced in 1909/10, this is noticeable by two horizontal brass strips on the cross front. Around 1914, the rear standard was placed on a focusing rack with a focusing pinion on the right (when in use) and a locking ring on the left.

The focal-plane shutter has three slits, a knob on the right of the camera (when in use) winds the shutter to the first position which is full width for focusing, a small button on the left when pressed allows the blind to be wound further to the second or third slit for exposure. When set the slit number is shown on the blind.

The Triple Extension Imperial was a mid-range field camera introduced in 1904.