This is a late version of he No. 7 fitted with a Prontor II shutter that was advertised from 1937. The name under which the camera was advertised changed in the mid/late 1930s. The camera itself is marked Ensign Carbine Tropical Model, advertisements refer to Tropical Ensign and Tropical Ensign - 20.

The No. 12 was the largest of the Tropical Carbines, it was a very well-made camera with teak sides and metal covering to the front and removable metal back. An air valve is present to prevent suction in the bellows when the front is pulled out. The first example above does not have the hinged spool retainers present on the second example (left of photograph) which were the subject of the 1926 patent.

Tropical Carbine models

The tropical version of the Carbine dates back to around 1922 when Butcher advertised a tropical version of the No. 6 (for 2 ¼" x 3 ¼" images). This was finished in black crystalline paint with Russia leather bellows.

By 1925 the finish was the familiar oxidised brass. This model had a choice of a 3 speed shutter or a Compur both with an Aldis lens.

In 1926 the No. 12 Watch Pocket Carbine (2 ½" x 4 ¼") was added, this had teak side panels with a brass front shell and back. Ross and Zeiss lenses were available for both sizes (No. 6 and No. 12). The finish at this point was described as 'copper oxidised Florentine bronze'.

In 1927 the No. 4 was added, this was a cheaper version of the No. 6 and was fitted with a 3 speed shutter. The No. 6 continued with a Compur shutter as did the No. 12.

By 1930 the No. 6 was replaced by the No. 7. The other two models remaining as before. The No. 7 survived until the late 1930s (renamed Tropical-Ensign-20 around 1936). The other two models ceased in the early 1930s. The No. 6 model (and No. 7) was available with a plate back to which could be fitted single metal slides, film pack adapters and a focusing screen.

The No. 7 took the same size film as the No. 6 but incorporated a number of new features, it was also noticeably taller. The changes were:

• The back was now hinged and secured by a spring clip.
• The film-winder was replaced by a round knob.
• A hinged spool pin was fitted, patent no. 281802.
• The focusing scale was moved to the left-hand side (when using the camera) and a radial focusing lever was fitted.
• The Houghton-Butcher 'Film Register Device' was fitted, patent 280352.
• A handle was added.
• Cross front was added.

Rim-set rather than dial-set Compur shutters were fitted to late examples.