I wonder why :43: cameras, such as the G1, have a mechanical (focal plane) shutter? Compact digital cameras don't need mechanical shutters. Panasonic wouldn't have done this unless it improved some aspect of the camera. How and what?
I heard rumours that the gh2 and or g2 will be physical shutterless and will use an electronic shutter only... of course that's just rumours.
Maybe the electronic shutter wasn't good enough at the time or something... I had read somewhere about how scanning / switching on/off of the photo-cells works on previous electronic shutters and it was said to be slow and caused sheering of the image, more severely than in physical shutters.
Of course I could be all wrong... I'm not a camera designer or anything.
Most digital point and shoot cameras, such as the 8MPixel Kodak Easyshare that Nikki has, use mechanical shutters. That is one of the reasons for the time lag when you take the picture. Shutter has to close as it was in liveview mode, open and close again for the picture, and then open again for liveview mode. Kind of like a Kodak Retina Reflex.
The GF1 has a mechanical shutter however, it is open when you take the lens off. I found this out because I set the camera to enable shooting without a lens then removed the lens and took a picture to see what happens.
Before getting my G1 I used an Olympus SP-350 compact digital camera. After watching more carefully as I press the shutter button, I find it has a mechanical shutter after all. But it has a leaf shutter instead of focal plane shutter. Therefore it is virtually silent. The camera lets me choose among several sound effects (or none) for the shutter. A leaf shutter can't be used with interchangeable lenses unless every lens includes a shutter. So Streetshooter may be correct after all.
It still seems odd that a shutter is required considering that live view or movie mode does not need a shutter.
I'm sure I read an explanation somewhere that showed why it is practical to provide an electronic shutter for a CCD sensor (which most digicams and camera phones use), there are issues in doing this with high end implementations of CMOS sensors, due to the way the sensor is 'read'. It may well be that this also applies to the MOS sensor used in various 3/4 cameras.
Liveview and Movies can let the sensors just read out continously. Trying to get a very short integration time across the entire sensor might be hard. I can look at some of the datasheets, but recall that was the problem as stated a long time ago by Kodak. Mechanical shutters have a lot of uses. "Choppers" they often get called in the Lab.