The Flutter-Shutter - helps eliminate motion-blur

A researcher at Mitsubishi Electric has invented a new kind of shutter which, in combination with specific post-processing, allows the photographer to take sharper pictures of moving subjects without requiring the usual combination of fast shutterspeed and large aperture. Fascinating stuff.

http://www.digitalcamerainfo.com/content/Mitsubishi-Electric-Develops-Deblurring-Flutter-Shutter-Camera-Partners-with-MITU-of-Toronto.htm

Murray McCulloch wrote:

A researcher at Mitsubishi Electric has invented a new kind of
shutter which, in combination with specific post-processing, allows
the photographer to take sharper pictures of moving subjects
without requiring the usual combination of fast shutterspeed and
large aperture. Fascinating stuff.

One of the things that I find interesting is their shutter. It looks as though their "ferroelectric" shutter is much faster than any mechanical shutter, but it shouldn't have the same problems as the electronic shutters used on some CCDs. It seems like it would be a cool thing to replace the mechanical shutter on a DSLR, since it would let you get very high flash sync speeds and would suffer from mechanical failure.
--

As with all creative work, the craft must be adequate for the demands of expression. I am disturbed when I find craft relegated to inferior consideration; I believe that the euphoric involvement with subject or self is not sufficient to justify the making and display of photographic images. --Ansel Adams

rgmoore wrote:

One of the things that I find interesting is their shutter. It
looks as though their "ferroelectric" shutter is much faster than
any mechanical shutter, but it shouldn't have the same problems as
the electronic shutters used on some CCDs. It seems like it would
be a cool thing to replace the mechanical shutter on a DSLR, since
it would let you get very high flash sync speeds and would suffer
from mechanical failure.

I'm not sure. The article says "... capture moving objects at an exposure time of over 50 milliseconds". 50ms is very slow - only 1/20s. But maybe when they say "over" they mean "faster than" (which to me would actually be "under").

If they could get this shutter to work as fast as 1/2000s (half a millisecond), it would seem to be a possible replacement for mechanical and electronic shutters. But I'm sure camera makers have already been researching that possibility -- I don't think the shutter technology itself is new, just the application.

Murray McCulloch wrote:

I'm not sure. The article says "... capture moving objects at an
exposure time of over 50 milliseconds". 50ms is very slow - only
1/20s. But maybe when they say "over" they mean "faster than"
(which to me would actually be "under").

I think that they mean that they can have a total shutter speed of over 50 miliseconds (i.e. shutter speed of 1/20s or slower) and still eliminate subject motion blur. I went ahead and downloaded their paper, which mentions that the "DisplayTech ferro-electric shutter" has a switching time of less than 100 microseconds. That would theoretically allow a 1/10000s shutter speed.

Dredging up some of DisplayTech's specs ( http://www.displaytech.com/downloads_04/Shutters.pdf ) suggests that it isn't going to be an adequate substitute for a mechanical shutter, at least at their current tech level. Their guaranteed performance is only 25% transmission and 75 lp/mm transmitted image quality, which seems like a big wet blanket. The absolute killer is the > 70% transmission of 900 nm IR even in the "OFF" position. Ah well, it sounded good.
--

As with all creative work, the craft must be adequate for the demands of expression. I am disturbed when I find craft relegated to inferior consideration; I believe that the euphoric involvement with subject or self is not sufficient to justify the making and display of photographic images. --Ansel Adams

I'm not sure. The article says "... capture moving objects at an
exposure time of over 50 milliseconds". 50ms is very slow - only
1/20s. But maybe when they say "over" they mean "faster than"
(which to me would actually be "under").

No, they're talking about milliseconds. They mean over, as in over 50 milliseconds.

If they could get this shutter to work as fast as 1/2000s (half a
millisecond), it would seem to be a possible replacement for
mechanical and electronic shutters. But I'm sure camera makers have
already been researching that possibility -- I don't think the
shutter technology itself is new, just the application.

http://www.displaytech.com/products/photonics/shutters.html
This company as an example is claiming 1/5,000s.

The problem is that these types of shutters require polarizers stacked on either side to work, let in IR light whether open or closed, won't work in really cold weather, are damaged by UV light, and only transmit around 30% of light... and those are just the problems I found in their product documentation. Most other products I was able to locate quickly had worse specifications and some mentioned only being able to "close" completely at a narrow range of temperatures....

Well, it sounded cool anyway.

I was telling this to an old friend of mine and she said

"well, what's new, if you sneeze and toot at the same time you get the exact same effect."

I haven't tried it...

Joseph S. Wisniewski wrote:

Murray McCulloch wrote:

A researcher at Mitsubishi Electric has invented a new kind of
shutter which, in combination with specific post-processing, allows
the photographer to take sharper pictures of moving subjects
without requiring the usual combination of fast shutterspeed and
large aperture. Fascinating stuff.

http://www.digitalcamerainfo.com/content/Mitsubishi-Electric-Develops-Deblurring-Flutter-Shutter-Camera-Partners-with-MITU-of-Toronto.htm

The shutter itself isn't new. It's a rather well known light
modulator. What they're doing with it is new.

Quite right; thanks for the correction.

It's another variation on "guided deconvolution", which I was
talking about a few months ago for removing camera shake.

It's way over my head.

This technique would probably be better applied to a camera who's
sensor already had an electronic shutter. That would get past all
the problems with the polarizer based shutter in the prototype.

Good point. I wonder if the researchers are looking into this. Seems that if they could collaborate with the camera makers to get into the CCD controller logic, they could do away with this shutter altogether.

I can see this capability being a feature of high end cameras in a few years. Perhaps specialised models only.

Joseph S. Wisniewski wrote:

This technique would probably be better applied to a camera who's
sensor already had an electronic shutter. That would get past all
the problems with the polarizer based shutter in the prototype.

Many electronic shutters just consist of releasing a reset signal, letting the exposure complete and then rapidly dumping the image to a light-insensitive buffer (an adjacent set of blacked-out charge well columns in a CCD, for example) so that it can be read out at will without further influence from the incident light. Although a second exposure can begin even as the first one is being clocked out, the duration of this second exposure must be at least as long as the buffer clearing time or there'll be no place to transfer this new exposure without corrupting the one currently being read out. Without having yet read the original paper to know the shutter speeds being discussed, I think this might limit the implementation of the flutter shutter method.

David

DRG wrote:

Joseph S. Wisniewski wrote:

This technique would probably be better applied to a camera who's
sensor already had an electronic shutter. That would get past all
the problems with the polarizer based shutter in the prototype.

Many electronic shutters just consist of releasing a reset signal,
letting the exposure complete and then rapidly dumping the image to
a light-insensitive buffer (an adjacent set of blacked-out charge
well columns in a CCD, for example) so that it can be read out at
will without further influence from the incident light. Although a
second exposure can begin even as the first one is being clocked
out, the duration of this second exposure must be at least as long
as the buffer clearing time or there'll be no place to transfer
this new exposure without corrupting the one currently being read
out. Without having yet read the original paper to know the shutter
speeds being discussed, I think this might limit the implementation
of the flutter shutter method.

Ah, another good point. I knew there had to be a problem with that idea.

Regarding the limitations of the shutter used in the prototype, I reckon that if they keep working on it they will eventually develop a form of electronic shutter like that which is able to block out all light when closed and also transmit much more when open, thus eventually becoming a viable replacement for a mechanical shutter.

However, I would miss the sound of that little click-click (although admittedly the mirror in a DSLR makes more noise than the shutter and it would still remain anyway).

I guess this would be okay for casual snaps that go wrong but judging by the samples the use of this technique will be obvious in the final photograph.