[TimothyB]

Hi, first post, I'm looking into getting a K-X, have a question with live view and shutter noise.

With a DSLR, turning on Live View, the shutter would open so the sensor can display on the screen. I noticed this when my dad opened a new D90 Nikon (back-up to his D3), and hitting live view, you could hear the shutter open, though, I didn't have time to test it further, and no card in it.

If a DSLR has it's shutter in the open position for Live View, and you take a photo, does the shutter bother to close and open? I would think that's unnecessary, unless the noise is just welcome reminder that the photo was taken.

I ask because it would be a handy way to take a photo while being silent if you don't mind using the screen and not the viewfinder.

I assume the shutter's main purpose these days on a digital slr is just for the view finder, as wouldn't the exposure be controlled digitally and not how long the shutter is open? Unless I'm wrong about that, still a newb.

[innershell]

That sound you hear is actually not the shutter being opened during Live View, but actually the mirror being raised. The shutter still opens and closes during Live View.

Others may correct me if I'm wrong.

[LeoTaylor]

This is a good question and I don't know the answer nor do I have a camera with live view. But here is a logical analysis.

In order for a DSLR to take a photo of say 1/60th of a second the shutter must start closed, open for 1/60th, and close. Thus I think Live View is temporarily interrupted so the shutter can close, open for the exposure setting, close, then open to resume Live View.

Does that make sense?

This does not apply to video mode where there is constant downloading of data from the sensor and limited control of exposure time.

[TimothyB]

Ah, I guess maybe one thing I didn't consider is that the shutter is still the mechanism to control the length of the exposure, like say that 1/60th of a second as mentioned. I first figured thought the sensor exposure was controlled digitally, like an on/off switch.

Trying to think back to holding that D90s for a few minutes. Without a memory card, I couldn't get an actuation when pressing the shutter button. Though, hitting live view, the mirror lifted, which you could hear, then when I pressed the shutter, I heard what sounded like a full actuation (even though still no memory card). Not sure if the mirror stayed up the whole time, and couldn't test if the shot took longer than without live view (like if the shutter had to close first, open, close, then open again for live view)

[knoxploration]

Ah, I guess maybe one thing I didn't consider is that the shutter is still the mechanism to control the length of the exposure, like say that 1/60th of a second as mentioned. I first figured thought the sensor exposure was controlled digitally, like an on/off switch.

Yup, you're correct. the shutter is held open before / after the exposure so that the live view feed can be clocked off the sensor, which is achieved with an electronic "shutter" since the mechanical shutter couldn't move fast enough (and would wear out too quickly).

For the actual exposure though, the mechanical shutter is used. The main reason for this is that the exposure is still adversely affected by light falling on the sensor while being read out. Hence higher image quality is achieved by closing the mechanical shutter so as to end the exposure during read-out.

Noise will still be significantly lower during a live view exposure though, because only the shutter mechanism needs to be triggered. The mirror remains raised the whole time, and that removes a significant portion of the noise normally heard during a non-live view exposure.