Can we do without shutters in digital cameras?

[chiranjeeb]

As I understand, a CCD array is just an array of capacitors whose

charges are read off one by one by an amplifier to generate the image

in a digital camera. If this is the case, and the CCD can be read

fast enough (faster than a millisecond) can we just eliminate the

shutter completely? I mean, when the button is pressed, one could

clear the CCD array of charges, wait for 1/100 sec (or whatever the

exposure time is set to), read the CCD array again and be done. No

shutter will be required at all. Of course, this will not work if

time required to read the array is comparable to the exposure time

itself. Does anybody know how much time it takes to read a CCD array?

[steve coburn]

Isn't this what happens with electronic 'shutters' anyway? If not then how do electronic shutters work?

[beau 1664876222]

I believe most digital cameras don't have traditional shutters, just variable on-off switches for the sensor. If you are referring to DSLRs, of course there's the whole mirror thing that still happens mechanically.

[chiranjeeb]

The D2H still has a focal plane shutter according to specs in dpreview.com. So I wonder why that is necessary.

[ian_wilson4]

There is still a focal plane shutter in DSLR cameras because the different imaging chips (CMOS vs CCD) require them. AFAIK anyways :)

[roger krueger]

An interesting datapoint is the Olympus E-20, which can be operated with the leaf shutter

in the lens to 1/640, or electronically shuttered to a higher (I think 1/4000) speed. The

catch is that at the higher (shutterless) speed you only get half resolution, I think because

the "extra" pixels have to be used as some sort of buffer during readout.

 

Shutters are expensive, prone to wear/failure, limit sync speed and cause mechanical

jarring of the camera during exposure--manufacturers would certainly eliminate them if

that made sense.

[colleendonovan]

I kind of like the sound shutters make. :) I think I would miss that.

[mormegil]

Sorry to burst your bubble, but that's probably the "mirror slap" you're hearing, not the shutter cycling.

[mesasone]

You are very obviously missing a HUGE apsect of photography: Depth of Feild. The apture IS the shutter, if you remove the shutter you lose all control over the DoF, the amount of light entering the camera beyond pure "capture time"(since we'd have no shutters).

 

What you would have would be a pin hole camera. Alot of the really cheap digital cameras are like this... fixed at "2.8" or such. Also, this is how camera phones function.

[roger krueger]

Camden: I have never EVER seen a camera that functions as you describe.

 

Sure, there are some megacheapies without aperture adjustment, but that has nothing to

do with the shutter. There are some medium and large format leaf-shutter lenses where

the actual shutter and aperture are housed in the same assembly, and the whole thing is

loosely referred to as the shutter,

 

But none of these has much bearing on digital--having an aperture without a physical

shutter is trivially easy, and there are a variety of cameras out there that do just that.