The Apus (アパス) are Japanese leaf shutters made by Rokuoh-sha and Konishiroku (predecessors of Konica).
Apus in #0 size
The large model, in #0 size, was introduced in 1933 on the Year-Eight Idea and Year-Eight Pearl. It was copied on the German Vario, and it was a cheaper alternative to the Durax.
The range of speeds is T, B, 100, 50, 25, selected on a dial at the top. The release lever is attached to the front face. The shutter is everset, with no cocking lever. The RK logo of Rokuoh-sha is directly engraved on the front face, and the APUS name is inscribed on the speed dial. There is a thread for a cable release on the side, on a small hole under the lens, for a thread and needle release (a crude replacement for a self-timer). It seems that the early examples of the Apus have an all black finish, whereas later ones have a silver rim, imitating a rim-set shutter.
The Apus in #0 size was mounted on the following cameras by Rokuoh-sha (not all the versions have this shutter):
- Year-Eight Idea, from 1933
- Year-Eight Pearl, from 1933
- Ohca, from 1935
Some #0 Apus were mounted on the Elliotte 6×6 pseudo TLR, distributed in the early 1950s. Its manufacturer surely re-used old parts disposed of by Konishiroku.
Apus in #00 size
A reduced version of the dial-set Apus was released in #00 size on the Luxury Pearlette, made from 1937 in small quantities. It is similar in function and design to the larger model.
A new rim-set Apus was released in #00 size at the beginning of 1938 for the 4.5×6cm Semi Pearl, in combination with an Optor lens. The range of speeds is slightly extended: 10, 25, 50, 100, B, T. The new model has a setting lever at the top and a release cam at the bottom, and is suited for cameras with a body release. There is a thread for a cable release on the side, towards the bottom, and no self-timer device. The shutter has a setting lever at the top and a release cam at the bottom, and is suited for cameras with a body release. There is a thread for a cable release on the side, towards the bottom, and no self-timer device.
It seems that the production of the Apus was not resumed after 1945. One isolated example is known with the new front face with Konishiroku marking adopted on the Durax, but its internals were probably assembled from old stocks of parts.