Why are shutters on digital cameras?

whuband wrote in post #8966329
The OP asks an interesting question. Electronic switching is far faster and more reliable than mechanical switching and is also silent. Switching a sensor off and on seems like a great idea. Sounds like a billion dollar patent to me. I haven't had a quiet camera since my old Leicas, which I wish I still had.

As has already been stated, current technology does not allow electronic switching to occur with the speed and precision necessary.

Or perhaps it the old "I've never heard of it so I'll just assume that nobody else has ever thought of this before" thing. You can be sure that Canon, Sony and all the other companies that develop image sensors have been working on this for some time. In fact, they probably already have it working but are still trying to figure out how to make them cheap enough to manufacture.

When they do get this working though it will be great. Not only will it be more quiet but it will allow the shutter speed to be varied over different areas of the sensor. The would be like having a built in graduated neutral density filter, darkening the bright sky and allowing a longer exposure on the darker ground areas.

whuband wrote in post #8966329
I haven't had a quiet camera since my old Leicas, which I wish I still had. Maybe it's the old "that's the way it's always been done" thing with cameras that prevents R & D in this area.

It's not the shutter you hear in your DSLR, it's the mirror. I guess those with Live View can compare mirror slap and shutter noise, but with my 30D all I can hear is the mirror.

-js

As krb said, there is much research going on in this area.

Yes, there are very fast CMOS switches out there, but they are not photoconductive. Those that are photconductive are not fast switches.

Some day, yes. All cameras will have fully electronic (and silent) shutters. And SLRs will be made with liquid crystal mirrors that never have to move, but rather switch from "silvered" to transparent.

But not yet.

DAMphyne wrote in post #8962294
P&S cams "Don't have a shutter"?
I figured they had a leaf shutter built into the lens.
Hmmm.

Nope, they don't.

I'm actually kind of annoyed that while my E-P1 has a mechanical shutter, the shutter is open except directly before and after an exposure. Obviously, this is necessary for live view, but when the camera is off, I want the shutter to close to block off dust when I'm changing lenses.

krb wrote in post #8966524
As has already been stated, current technology does not allow electronic switching to occur with the speed and precision necessary.


Or perhaps it the old "I've never heard of it so I'll just assume that nobody else has ever thought of this before" thing. You can be sure that Canon, Sony and all the other companies that develop image sensors have been working on this for some time. In fact, they probably already have it working but are still trying to figure out how to make them cheap enough to manufacture.

When they do get this working though it will be great. Not only will it be more quiet but it will allow the shutter speed to be varied over different areas of the sensor. The would be like having a built in graduated neutral density filter, darkening the bright sky and allowing a longer exposure on the darker ground areas.

I agree. You made my point. When it's developed, it will be a billion dollar patent. Electronic is far superior to mechanical, or we would still be shooting with cameras from the 1970's.

The Nikon D70 and D50 dSLR series used a combination electronic and mechanicla shutter. Shutter speeds slower than 1/500 were controlled by the mechanical shutter. Speeds from 1/500 - 1/8000 were controlled by the sensor. The shutter would open, the sensor would turn on and off for the selected shutter speed. This was pretty cool because you could sync *full* power flash at high shutter speeds.

The only problem that I am aware of with these shutters is blooming. When you shot straight into a bright light source (the sun or something) at high shutter speeds, there was a chance that vertical white lines would appear. These lines would be straight up and down starting from the light source. The blooming would only appear at the shutter speeds that were electronically controlled.

beavo451 wrote in post #8970481
The Nikon D70 and D50 dSLR series used a combination electronic and mechanicla shutter. Shutter speeds slower than 1/500 were controlled by the mechanical shutter. Speeds from 1/500 - 1/8000 were controlled by the sensor. The shutter would open, the sensor would turn on and off for the selected shutter speed. This was pretty cool because you could sync *full* power flash at high shutter speeds.

The only problem that I am aware of with these shutters is blooming. When you shot straight into a bright light source (the sun or something) at high shutter speeds, there was a chance that vertical white lines would appear. These lines would be straight up and down starting from the light source. The blooming would only appear at the shutter speeds that were electronically controlled.

That's not a fault. That's a Nikon "feature"!

number six wrote in post #8968023
It's not the shutter you hear in your DSLR, it's the mirror. I guess those with Live View can compare mirror slap and shutter noise, but with my 30D all I can hear is the mirror.

-js

The mirror is definitely the louder of the two but if you use the mirror lockup function to separate the two movements, you'll hear the shutter does make noise.

beavo451 wrote in post #8970481
The Nikon D70 and D50 dSLR series used a combination electronic and mechanicla shutter. Shutter speeds slower than 1/500 were controlled by the mechanical shutter. Speeds from 1/500 - 1/8000 were controlled by the sensor. The shutter would open, the sensor would turn on and off for the selected shutter speed. This was pretty cool because you could sync *full* power flash at high shutter speeds.

The only problem that I am aware of with these shutters is blooming. When you shot straight into a bright light source (the sun or something) at high shutter speeds, there was a chance that vertical white lines would appear. These lines would be straight up and down starting from the light source. The blooming would only appear at the shutter speeds that were electronically controlled.

They were able to do an electronic shutter on these cameras because the cameras use CCD rather than CMOS sensors. On the plus side you get the electronic shutter and higher flash synch speeds. On the down side you get the noise and image quality of a CCD.

mike_d wrote in post #8970678
The mirror is definitely the louder of the two but if you use the mirror lockup function to separate the two movements, you'll hear the shutter does make noise.

How can you hear the shutter? Mirror lockup raises the mirror early, but the mirror drops immediately after it's closed, masking any shutter noise.

I sure can't separate shutter noise and mirror-drop noise in my 30D. But those with live view should be able to...

-js

-js

number six wrote in post #8972709
How can you hear the shutter? Mirror lockup raises the mirror early, but the mirror drops immediately after it's closed, masking any shutter noise.

I sure can't separate shutter noise and mirror-drop noise in my 30D. But those with live view should be able to...

-js

-js

Enable mirror lockup and set your shutter for 1 second.

Push the shutter button and THUNK, you hear the mirror raise

Push the shutter a second time and, TICK, you hear the shutter open.

At the end of the exposure, the shutter closing sound is masked by the mirror dropping.

There ya go! I wasn't thinking very hard, was I?

My shutter (opening) is about half as loud as the mirror drop.

-js