The concept of the retractable shutter is maintained but the lens itself
becomes more sophisticated. It is a Tourret-Narat f=45mm labeled
To be pointed, this front lens is protected with a blue filter which
can be dismounted.
Rotating the ring supporting this filter allows to adjust the
distance to the subject in a range between 1m to the infinite.
The shutter ATOS gives 6 speeds : 1/25sec, 1/50sec, 1/100sec,
1/150sec, 1/250sec and a pause B.