I was wondering how the modern camera
stabilization sytems work, I mean the systems
used on small hand held video cameras??
I thought they used some type of gyro, and I was
wondering about the systems and the gyro's. Are
these gyro's without moving parts? Is something
spinning or is there another way to make a gyro
without spining pieces??
Subject: [ot]: How do camera stabilization systems work?
Hello Picsters!
I was wondering how the modern camera
stabilization sytems work, I mean the systems
used on small hand held video cameras??
I thought they used some type of gyro, and I was
wondering about the systems and the gyro's. Are
these gyro's without moving parts? Is something
spinning or is there another way to make a gyro
without spining pieces??
Yes, they use gyros. Ultrasonic gyros where the u/s mechanical
wave bounces around inside a piezo crystal. They sense the phase shift
resulting from motion, and then change the clock timing on the CCD chip
so that the image gets stabilized as it gets shifted out. This
technique can only compensate for horizontal/vertical motion, not
rotation, but that is sufficient for most users.
>
> Hello Picsters!
>
> I was wondering how the modern camera
> stabilization sytems work, I mean the systems
> used on small hand held video cameras??
>
> I thought they used some type of gyro, and I was
> wondering about the systems and the gyro's. Are
> these gyro's without moving parts? Is something
> spinning or is there another way to make a gyro
> without spining pieces??
>
> Thanks
>
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What type of gyros are you talking about? I have been working on an
inertial measurement project for the last year and I haven't come across
that type. Do you have links for them? I'd be very interested.
We use piezo gyros (which operate at around 25kHz) but,AFAIK, they really
do vibrate a piezo crystal and sense the flexing of the crystal due to
Coriolis force. I have heard of laser ring gyros
(many $$$) which sense the phase shift in a pair of laser beams going
around a ring, but I doubt that would work with sound waves (since it uses
relativistic effects). The only type similar to what you mention that I
have heard of is a proposed idea of transmitting sound waves inside a
gas-filled chamber and sensing the changes in standing wave pattern due to
the Coriolis force's effect on the boundary layer around the chamber walls.
>Yes, they use gyros. Ultrasonic gyros where the u/s mechanical
>wave bounces around inside a piezo crystal. They sense the phase shift
>resulting from motion, and then change the clock timing on the CCD chip
>so that the image gets stabilized as it gets shifted out. This
>technique can only compensate for horizontal/vertical motion, not
>rotation, but that is sufficient for most users.
>
>Checkout the website
>http://www.howstuffworks.com
>for hundreds of explanations on other stuff.
>
>rad0 wrote:
> >
> > Hello Picsters!
> >
> > I was wondering how the modern camera
> > stabilization sytems work, I mean the systems
> > used on small hand held video cameras??
> >
> > I thought they used some type of gyro, and I was
> > wondering about the systems and the gyro's. Are
> > these gyro's without moving parts? Is something
> > spinning or is there another way to make a gyro
> > without spining pieces??
> >
> > Thanks
> >
> > --
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> Yes, they use gyros. Ultrasonic gyros where the u/s mechanical
> wave bounces around inside a piezo crystal. They sense the phase shift
> resulting from motion, and then change the clock timing on the CCD chip
> so that the image gets stabilized as it gets shifted out. This
> technique can only compensate for horizontal/vertical motion, not
> rotation, but that is sufficient for most users.
>
Yes they all use piezo gyros but at least one camera manufacturer
uses a 2-axis-coil-lense-in-a-servo arrangement, like a cd lense to
keep the image stable. That is... electro-mechanical stabilization.
Lance Allen
Technical Officer
Embedded Systems Lab
Computer Systems Engineering
Department of Electrical
and Electronic Engineering
University of Auckland
New Zealand
> I thought they used some type of gyro, and I was
Hmm. I don't really know much about the cameras, but I didn't think that
they used gyros.
My understanding was that they had an "oversized" ccd, and only used a
(NTSC sized) subregion of the full ccd to form the image. There are algs.
that have been developed to detect camera movement from sequences of
images...I figured they detected movement and corrected for it by moving
the image region around within the ccd space.
> > I thought they used some type of gyro, and I was
>
> Hmm. I don't really know much about the cameras, but I didn't think that
> they used gyros.
>
> My understanding was that they had an "oversized" ccd, and only used a
> (NTSC sized) subregion of the full ccd to form the image.
Come to think of it (pontificate in haste, backpedal at leisure) all
the steady cameras I have seen the workings of use piezo gyros BUT
that doesnt mean there has since been far cheaper/better solutions
developed.
There is a world of variations out there. Like the (at least) 2
ways of steadying the image itself.
Lance Allen
Technical Officer
Embedded Systems Lab
Computer Systems Engineering
Department of Electrical
and Electronic Engineering
University of Auckland
New Zealand
>My understanding was that they had an "oversized" ccd, and only used a
>(NTSC sized) subregion of the full ccd to form the image. There are algs.
>that have been developed to detect camera movement from sequences of
>images...I figured they detected movement and corrected for it by moving
>the image region around within the ccd space.
I doubt that the big Canon 35mm SLR lenses or the IS binoculars work that
way. Video cameras, maybe.
This is what I'm wondering about, How do the big
Cannon Binoculars work?? They (Cannon) have 18x50
binoc's that have IS image stabilization. What are they
doing here. Thanks all. ...
Hey, If you want to view the seven sisters or the
b____ next door, you've got to know how it;s done -;)
I've seen cameras that do something like this. When image stabilization is
turned on, what you see in the viewfinder "zooms in". I.e. if you have a
10" field of view, then turn on stabilization, it jumps to a 9" field of
view. The image you see is a small part of the real image, the
stabilization system just shifts the rectangle containing the recorded
image. I don't know what systems are used. I would think accelerometers
could be used.
Lance Allen wrote:
> On 17 Oct 00 at 12:58, Robert Rolf wrote:
> > Yes, they use gyros. Ultrasonic gyros where the u/s mechanical
> > wave bounces around inside a piezo crystal. They sense the phase shift
> > resulting from motion, and then change the clock timing on the CCD chip
> > so that the image gets stabilized as it gets shifted out. This
> > technique can only compensate for horizontal/vertical motion, not
> > rotation, but that is sufficient for most users.
> >
> Yes they all use piezo gyros but at least one camera manufacturer
> uses a 2-axis-coil-lense-in-a-servo arrangement, like a cd lense to
> keep the image stable. That is... electro-mechanical stabilization.
>
> Lance Allen
That would be the old Sony TR101. Much better stabilization than
the new 'all digital' ones. Did have problems with bellows leakage
though. IMS JVC also had a EM stabilized version around the time (1995).
Now, if you're talking about the professional CAMERA stabilizers
(AeroCam
and the like), that unit does use a spinning gyro, and some clever
mechanics for vibration isolation (including an 'active' suspension).
> On 17 Oct 00 at 15:52, Stephen B Webb wrote:
>
> > > I thought they used some type of gyro, and I was
> >
> > Hmm. I don't really know much about the cameras, but I didn't think that
> > they used gyros.
They use piezo gyros to sense the motion vectors.
Just look in the service manual for descriptions & part numbers.
The now discontinued 'Gyropoint mouse (about $50.US)' used piezo
gryos. A colleague of mine gutted about 50 of them for the gyros because
it was cheaper to do that the buy them from Murrata. There are many
sources now.
> > My understanding was that they had an "oversized" ccd, and only used a
> > (NTSC sized) subregion of the full ccd to form the image.
That is exactly how the newer Sony system works. With gyros to sense
the motion correction required. Lower overhead than DSP methods.
There is also an 'all digital' system that commercial broadcasters
use that basically does a 10% digital zoom on the incoming video, and
then uses DSP's (motion vector extraction) to correct the motion. $$$.
You can find out more about this by digging up back issues of the SMPTE
journal (circa 1995).
> Come to think of it (pontificate in haste, backpedal at leisure) all
> the steady cameras I have seen the workings of use piezo gyros BUT
> that doesnt mean there has since been far cheaper/better solutions
> developed.
> There is a world of variations out there. Like the (at least) 2
> ways of steadying the image itself.
3 if you count the DSP method. The DSP method can also correct for
rotation, something the other two can't do.
My understanding was that the domestic "Handycam", camcorder etc.
stabilisation systems used an oversized CCD & software stabilisation, while
the commercial broadcast quality systems used gyro stabilisers.
Richard P
On 17 Oct 00 at 15:52, Stephen B Webb wrote:
> > I thought they used some type of gyro, and I was
>
> Hmm. I don't really know much about the cameras, but I didn't think that
> they used gyros.
>
> My understanding was that they had an "oversized" ccd, and only used a
> (NTSC sized) subregion of the full ccd to form the image.
Come to think of it (pontificate in haste, backpedal at leisure) all
the steady cameras I have seen the workings of use piezo gyros BUT
that doesnt mean there has since been far cheaper/better solutions
developed.
There is a world of variations out there. Like the (at least) 2
ways of steadying the image itself.
Lance Allen
Technical Officer
Embedded Systems Lab
Computer Systems Engineering
Department of Electrical
and Electronic Engineering
University of Auckland
New Zealand
I had the misfortune to drop my sony tr88 camera on holiday last year. As I
was on a relativly small island with few if any electronic repair centers, I
decided to open it my self. The image stabilization circuitry involved 2
Murata type gyros mounted at right angles to each other at the front of the
camera. I didn't see anything I recognised as an accelerometer.
Joe
BTW I got the camera working by re connecting the pcbs which had become
displaced. A remaining intermittant fault was cured by flexing a pcb, so I
used a child's eraser to keep it flexed. It lasted just fine till I got
home. I would have to say though that working on something like this with
just a jewlers screwdriver and 2 small kids who REALLY wanted to help daddy
is not for the faint of heart....
Shoot, I've always thought cheap image stabilisation could be done by making the
CCD and lens system float slightly inside the camera, with a finely tuned mass
and shock/spring system. I imagined they could find an approximate frequency of
natural hand vibrations and simply tune them out mechanically. This would make
the camera heavier than an electronic system, though.
>
> I've heard:
>
> 1) gyros
> 2) multi-axis accelerometers.
> 3) edge sensing (in the image) via DSP software.
>
> Some apparently work better than others. (3) was described in conjunction
> with a camera whose image stabilization was said NOT to work very well.
>
> BillW
>
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William Chops Westfield wrote:
>
> I've heard:
>
> 1) gyros
> 2) multi-axis accelerometers.
> 3) edge sensing (in the image) via DSP software.
>
> Some apparently work better than others. (3) was described in
conjunction
> with a camera whose image stabilization was said NOT to work very well.
The image stabilization that I am familiar with over scan in each direction
by
40 pixels or so. They then compute the center mean intensity of the image
in each axis and adjust the start of line and start of scan line position
from
frame to frame.
The image stabilized binoculars use mechanical means (mass) to make
dynamic changes in the optical path.
> William Chops Westfield wrote:
> >
> > I've heard:
> >
> > 1) gyros
> > 2) multi-axis accelerometers.
> > 3) edge sensing (in the image) via DSP software.
> >
> > Some apparently work better than others. (3) was described in
> conjunction
> > with a camera whose image stabilization was said NOT to work very well.
>
> The image stabilization that I am familiar with over scan in each
> by
> 40 pixels or so. They then compute the center mean intensity of the image
> in each axis and adjust the start of line and start of scan line position
> from
> frame to frame.
>
> The image stabilized binoculars use mechanical means (mass) to make
> dynamic changes in the optical path.
>
> Walter Banks
>
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>
>
The currently used image stabilization methods use either electronic
sensing or mechanical (gyro) sensing. They use either electronic or
electro-optical image correction.
Electronic sensing involves a frame store buffer and a microcomputer or
DSP that 'locks' onto details in the image. When they shift it senses the
direction and magnitude of the shift. This is the earliest system that was
used, by Panasonic I think, more than 6 years ago afaik. It is confused by
rotation combined with shifting.
Mechanical sensing involves rate gyros with no moving parts made by Murata
or Tokin. They use the Coriolis effect as someone else has pointed out.
Electronic correction involves a frame buffer that has a readou window
that is movable in it. In other words, only about 80% of the real image is
output, and the controller shifts this smaller rectangle in the larger
image to compensate (apparently) for shake and motion.
Optical correction involves an electro-optical system that 'bends' the
lightpath in the camera under control from the computer. This is the best
system on sale today afaik, and this is what is called 'Optical image
stabilization'. It usually uses ceramic gyros and is independent of a
digital image of any kind. So it works in binoculars and still lenses. The
major deployers are Sony and Canon.
The best systems on sale today combine both feature sets for outstanding
results. You can shoot a picture of a 3 ft object at over 100 meters using
image-filling zoom freehand (no tripod, nothing). Of course I suspect that
military systems are FAR batter than this. Especially them things the
Comanche helicopters carry under their noses (and which things seem to
have been adapted for Olympics use in Sydney - or were those their poor
relatives ;-).
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Alexandre Domingos F. Souza wrote:
> Canon 35 mm SLR does not have stabilization.
Yes, they do. The stabilization is done in the *lens* instead of the camera
body itself. The catch is you have to get one of the lenses that have this
capability. I could find five different lenses on Canon's website that have
this - one zoom and four fixed length. URL for the zoom lens is:
The fixed lenses can be linked to from this page - look at the list of
lenses on the left all the way at the bottom ... the ones with the "IS" in
the model name are the ones.
-- Mike Werner KA8YSD | He that is slow to believe anything and
| everything is of great understanding,
'91 GS500E | for belief in one false principle is the
Morgantown WV | beginning of all unwisdom.
part 2 233 bytes content-type:application/pgp-signature (decode)
At 12:11 AM 10/19/2000 -0200, you wrote:
>>I doubt that the big Canon 35mm SLR lenses or the IS binoculars work that
>>way. Video cameras, maybe.
>
> Canon 35 mm SLR does not have stabilization. The IS binoculars use
gyros with a kind of "voice coil" moving the prismas, AFAIK
>
BTW, for those with a bent for building things, you can make a
nice little movable thingamajig using a small lever tied in the
middle to a pivot point, and one end glued to a tiny speaker.
I invented one of these things once, but of course, the boss
left my name off the patent - they called it [kinda hate to
say this in mixed company] --> the nutating probe.
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> >We use piezo gyros (which operate at around 25kHz) but,AFAIK, they really
> >do vibrate a piezo crystal and sense the flexing of the crystal due to
>
> Where do I find these? Are they equal to the Heli Model's Gyros? I
have some Gyros here waiting this module to be fixed... {Quote hidden}
>home. I would have to say though that working on something like this with
>just a jewlers screwdriver and 2 small kids who REALLY wanted to help daddy
>is not for the faint of heart....
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