The series I Advocate was introduced in 1949 and fitted with an f4.5 lens. It had a die-cast body finished in a very distinctive ivory coloured stove enamel.

The series II introduced in 1952 had an f3.5 lens and flash synchronisation for bulbs. Late models of the series II (advertised in the 1957 BJA) were available for either bulb or electronic flash.

Late in its life a version with a Wray lens was introduced, unofficially known as the series III. Very few of this type were made.

Accessories available:

• Ever-ready Case.
• Filter mount.
• Lens hood, fits onto the filter mount.
• Supplementary lens, 12" - 16 ½".
• Lens cap, black enamel, velvet lined.
• Combined filter mount and lens hood. This fits directly onto the lens.
• Transparency viewer.

The camera body was adapted for use in many scientific and engineering applications such as recording and microscopy.