Digital camera and Shutter

[Randall Ainsworth]

There's no physical shutter as in days of old. The sensor gets turned
on and off for the amount of time you've determined.

[Andrew McDonald]

Randall Ainsworth wrote:

> There's no physical shutter as in days of old. The sensor gets turned
> on and off for the amount of time you've determined.

That's not necessarily true. My Canon S230 and Coolpix 5000 both have
mechanical shutters.

And of course Digital SLR all have a shutter.

So it depends on the camera.

[Roland Karlsson]

John Navas <spamfilter0@navasgroup.com> wrote in
news:fWBPa.932$dk4.37170@typhoon.sonic.net:

> FYI, some digital cameras have electronic shutters, but some digital
> cameras have mechanical (physical) shutters. What matters is the type
> of sensor. See
> <http://www.dpreview.com/learn/Glossary/Camera_System/Sensor_01.htm>
>

My Canon G2 has a shutter. But ... I am not 100% sure how
it is used. It might just be for protection of the sensor,
not to actually decide the shutter time.

Anyone?



Roland

[LSE]

Hello,

Thanks, And do you know wich kind of mechanical shutter these camera
use ?

Another related question : how does eletronic shutter relates to flash
sync ? (the reason for flash sync speed limit was the physical limit
of mechanical shutters)

Luc

On Fri, 11 Jul 2003 16:51:23 GMT, John Navas
<spamfilter0@navasgroup.com> wrote:

>>There's no physical shutter as in days of old. The sensor gets turned
>>on and off for the amount of time you've determined.

>
>FYI, some digital cameras have electronic shutters, but some digital cameras
>have mechanical (physical) shutters. What matters is the type of sensor. See
><http://www.dpreview.com/learn/Glossary/Camera_System/Sensor_01.htm>

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[Tom Thackrey]

On 11-Jul-2003, LSE <luc@saint-elie_dot_com> wrote:

> Which kind of shutter do digital camera use ????
> This kind of information seems to become obsolete none of the
> technical specifications sheet give this precision

Not all digital cameras use mechanical shutters, in which case they probably
don't mention it in their specifications. Look at the DSLRs and you will see
specifications for the shutters.

--
Tom Thackrey
[url]www.creative-light.com[/url]

[John O.]

In article <rlstgv8e8e3p4dahkftp90oiv7dtkqmu8r@4ax.com>, luc@saint-
elie_dot_com says...

> Hello,
>
> Thanks, And do you know wich kind of mechanical shutter these camera
> use ?

I think what everyone is saying is that there isn't ONE kind of
mechanical shutter. It would depend on the camera. You'll probably find
the same types as you will find on film cameras.

>
> Another related question : how does eletronic shutter relates to flash
> sync ? (the reason for flash sync speed limit was the physical limit
> of mechanical shutters)

They relate the same way they did on film. And the reason for sync speed
is not the mechanical limit of the shutter. It is has to do with the
duration of the actual flash. Minolta actually has a "high speed" sync
on some SLRs that go to 1/4000 of a second.

--
John O.
There is no slack in light attack.

[Andrew McDonald]

John Navas wrote:

> FYI, some digital cameras have electronic shutters, but some digital cameras
> have mechanical (physical) shutters. What matters is the type of sensor. See
> <http://www.dpreview.com/learn/Glossary/Camera_System/Sensor_01.htm>

But that is still not the determining factor. My S230 and CP5000 are
interline since they can provide a constant video feed. These sensors
don't "require" a mechanical shutter but both cameras have one.

I don't know what sensor the D100 uses although I am guessing it's full
frame which absolutely requires a mechanical shutter.

It's just going to depend on the camera.

[Andrew McDonald]

John O. wrote:

> They relate the same way they did on film. And the reason for sync speed
> is not the mechanical limit of the shutter. It is has to do with the
> duration of the actual flash. Minolta actually has a "high speed" sync
> on some SLRs that go to 1/4000 of a second.

Yup. The 5400HS flash was able to "pulse" the light to make it last
longer so that it could put out light for the entire time the "slit" in
the shutter was moving across the film.

This resulted in less flash intensity but was ideal for fill flash
situations where the flash distance was not an issue.

[LSE]

On Fri, 11 Jul 2003 12:04:12 -0700, John O. <onewirealphaNO@yahoo.com>
wrote:

Sorry if I fail to express myself very well, English is not my native
language

In film camera there are basically two family of shutter :
1- curtains ones (old where textile curtains, more modern are
made in high tech metal. These shutter are found basically in SLRs and
in some rangefinder camera (Leica M)
2- cheap shutters that look like some king of aperture system
found on compact camera.

In film world things are very simple because there are NOT high level
compact (except for very special camera from Konica and some other,
but basically good camera = SLR, cheap camera = compact)

In the digital world nearly ALL camera are compacts (there are very
few SLR) so my question remain. For example does the expensive Nikon
5400 or Canon G5 use the same kind of shutter than the cheap Canon A40
CoolPix 3100 for example ??

In the film world if a manufacturer would say only "there is a shutter
inside" everybody would ask "hey.. which kind.. or even which brand..
most of mechanical shutter been made by Seiko).

And even if the manufacturer doesn't want to answer its not a drama
because everyday can see the shutter of a film camera.. did you see a
shutter in a digital camera ? you're lucky I can't see it.

>> Another related question : how does eletronic shutter relates to flash
>> sync ? (the reason for flash sync speed limit was the physical limit
>> of mechanical shutters)

>
>They relate the same way they did on film. And the reason for sync speed
>is not the mechanical limit of the shutter. It is has to do with the
>duration of the actual flash. Minolta actually has a "high speed" sync
>on some SLRs that go to 1/4000 of a second.

No the flash sync is the shortest laps of time where the film is
exposed completely, with shorter time the second curtain start before
the first arrived so only a row of light goes on the film from one
side to the other.

Some manufacturer cheat by using the flash as a stroboscope, the flash
launch a pool of flashes trying to follow the small distance between
the two curtains.

In the digital world, if the shutter is not more used for exposure,
this would mean that in some (not a long ) time the concept of flash
sync will disappear, this is not a "light" consequence.

Luc

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[LSE]

On Fri, 11 Jul 2003 17:44:10 -0400, "Aaron Bredon"
<abredon@bigfoot.com> wrote:

>On Fri, 11 Jul 2003 23:16:18 +0200, LSE wrote:

>> On Fri, 11 Jul 2003 12:04:12 -0700, John O. <onewirealphaNO@yahoo.com>
>> wrote:
>> In film camera there are basically two family of shutter :
>> 1- curtains ones (old where textile curtains, more modern are
>> made in high tech metal. These shutter are found basically in SLRs and
>> in some rangefinder camera (Leica M)

>
>This class is called Focal Plane shutters (the shutter is located at the
>focal plane in front of the film). The main advantage of this class of
>shutter is that the shutter is in the body of the camera, making it easier
>to design cameras with removable lenses. one disadvantage of this class of
>shutter is that they are slower to open and close and achieve higher
>shutter speeds by moving a slit across the film. this leads to
>expansion/compression of fast-moving objects depending on their movement
>relative to the shutter movement. another disadvantage is the slow flash
>sync speed.

Absolutely.. sorry for my poor vocabulary

>> 2- cheap shutters that look like some king of aperture system
>> found on compact camera.

>
>This class is not 'cheap shutters'.
>These shutters are called 'leaf' shutters due to the construction out of
>multiple pieces that look like leaves.

It's not exactly what I meant.
You'll find leaf shutter for example in large format (view camera for
instance) or medium format cameras. In these conditions there are
absolutely not "cheap" shutters, true.

What I was talking about are the shutters found in entry to mid-level
35mm compact cameras.

As far as I know ALL 35mm SLR (and high quality non SLR like Leica and
similar) used focal plane shutter.

I don't know a single compact 35mm that uses one.

Basically my question is in two parts :

1- quality : which kind of shutter are used in digital camera, I fail
to find info except "mechanical".. that as not real meaning, every
shutter but electronic ones are mechanical.

2- real use of the shutter. I fail to find clear information about the
use of a shutter in a non-full frame sensor camera.
The importance is that if the shutter is used to control the exposure,
the 35mm flash sync stuff remains current.
If the shutter is used to protect the sensor (or for other
non-exposure related work) I'd be interested in finding information of
the electronic system performance and on the relationship with flash
(flash sync speed becoming probably obsolete)


Luc

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[LSE]

On Sat, 12 Jul 2003 00:12:23 +0200, LSE <luc@saint-elie_dot_com>
wrote:

>Basically my question is in two parts :
>
>1- quality : which kind of shutter are used in digital camera, I fail
>to find info except "mechanical".. that as not real meaning, every
>shutter but electronic ones are mechanical.
>
>2- real use of the shutter. I fail to find clear information about the
>use of a shutter in a non-full frame sensor camera.
>The importance is that if the shutter is used to control the exposure,
>the 35mm flash sync stuff remains current.
>If the shutter is used to protect the sensor (or for other
>non-exposure related work) I'd be interested in finding information of
>the electronic system performance and on the relationship with flash
>(flash sync speed becoming probably obsolete)

My english is por but I just found one info

[url]http://www.usa.canon.com/EOS-1D/faqs.html[/url]


Q: Were the maximum 1/16,000-second shutter speed and 1/500-second
X-sync made possible by a mechanical shutter?

A: No, they were realized by an electronic shutter that changes the
duration of time that electric signals are stored in the CCD sensor.
The mechanical shutter employed in the EOS-1D works only when
controlling the bulb exposure length, and also functions as a cover
that protects the CCD sensor.

Does any body know where I could fin info of the electronical shutter
and current use of mechanical ones in current digital cameras ?

Luc

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