Shutter Speed Below Frame Rate

[Lloyd Coleman]

The A1 (and probably other camcorders) allow you to set the shutter speed slower than the frame rate. How is this possible? For example, if I open the shutter for 1/6 of a second, 5 frames of video are captured while the shutter is open, therefore, each frame was not exposed for 1/6 of a second. It seems like the frame rate is as slow as the shutter could effectively operate.

Thanks for helping me understand this.

[Bogdan Tyburczy]

It's all electronic process. In your example, camera allows to accumulate images on sensors for 1/6 second just like photo cameras do, then closes electronic shutter and generates 5 identical frames based on accumulated image. The process is repeated 6 times per second resulting with 6 images sent out in stream of 30 frames.

[Chris Hurd]

Right, those slow shutter speeds are electronically created. There's nothing "mechanical" about them.