[marknorton]

Shutter Lock

When the shutter is fully cocked, a lever is actually which “sticks” in the actuated position using a permanent magnet solenoid. These use a pulse of power to release them, not actuate them.

Here is it in “unlocked” position:

Shutter Lock - Unlocked.jpg

Here is it in “locked” position:

Shutter Lock - Locked.jpg

You can see the armature – the bit that moves - has been filled with silicone, presumably to stop it rattling and making a noise. There’s another position sensor on the reverse side so that the micro can tell if the shutter is locked or not.

In operation, as the shutter is cocked, the armature moves towards to solenoid and sticks because the core is a permanent magnet. Under microprocessor control, a current is passed through the solenoid to release it.

It was said the that the change to the shutter noise in V1.092 firmware was because this lock is released earlier in the shutter release cycle and becomes audible as a separate event.

The shutter is cocked using a small motor made by a Japanese manufacturer, Namiki, and a finely engineered gear train which turns the cam. The profile of the cam has, apparently been tailored to provide the best action with the shutter.

In this picture, you can see the complete shutter cocking motor, shutter lock and control electronics.

Shutter Wind 3.jpg

With some unsoldering, I’ve removed the circuit and unfolded it:

Shutter Controller.jpg

I tried running the motor directly from a 3v battery and, outside the camera, it is much quieter than when inside. I think at least some of the excessive shutter noise comes from vibrations from the motor being amplified because it is directly mounted on the camera body. A compliant mounting to reduce transmission might reduce the noise.