Want to know why shutter is necessary for DSLR

[mukul_chou]

I have Powershot A450 [CCD sensor] that seems does not have any shutter assembly.And it can capture up to 1/2000 sec.
Mobile cameras also do not have any physical shutter mechanism.

Why shutter assembly is necessary for a DSLR?

If that dslr can do without any physical shutter assembly it can definitely reduce cost, camera shake etc. etc.

techno geeks, please enlighten me

[Sean Setters]

Hi Mukul,

Check out this resource. It does a decent job of summing up the main points, I think:
http://www.steves-digicams.com/knowl...-shutters.html

[apersson850]

When using Live view, the camera does use a first curtain electronic shutter, since the sensor is already exposed to light when you press the button to take the picture. But then the mechanical shutter is used to end exposure and keep the sensor in the dark during image readout. This has the disadvantage that the sensor has to be cleared before exposure starts, compared to a sensor that's active already when the shutter button is half-pressed and just requires the shutter to open to capture the image.