Image Stabilization vs Noise

On Thu, 21 Dec 2006 10:44:48 -0800, Phil Wheeler
wrote:

jpc wrote:
Based on some published information from a review site, IS point and
shoot camera seem to be more noisy than non IS camera. This I'm
blaiming on electrical pickup from the piezo motors used to move
either a lens element or the sensor.

Anyone have any experience or comments on this topic


It would help if you provided a link to the review
site.


Yesterday was a busy day, so I didn't get a change to get back to
anyone's post.

The review site I'm using is imaging-resource.com. While I believe
they mentioned high noise in a review of a Canon IS P&S, what I've
done is use the DaveBox images to do my own noise analysis. If you
take the trouble to extract the information, these images are a
treasure trove of information on camera performance since the
imaging-resource people have been taking pictures of the same target
under the same lighting conditions for the last 12 years.

Here is my procedure if you want to duplicate the data I have on my
screen right now.

Go to the Canon 5D, Canon S3IS and Oly SP350 reviews. Download the
200 and 400 ISO low light (11lumen) davebox images of all three
cameras. These are at the end of the review and are the one's I've
been using since 11 lumens is roughly the light level you'd see at
night on a lighed city street.

Next Google ImageJ and go to the NIH website for a free download.
ImageJ is an excellent image analysis package that will do many things
but the only thing you have to do is hit the line icon on the tool bar
and drag a line down the grey scale section on the right central part
of your davebox images. Then hit Cnrl-K and a staircase graph will pop
up. You'll see the value (0-255) for each step in the grey scale with
the noise superimposed on the steps.

The Canon5D is our standard. Notice how all the noise is low and all
the steps are easily seen. (The bumpiness near the bottom is a target
problem). Also notice how the noise stays constant.

Next look at at SP350 graph--one of the tiny pixel (5 square microns)
camera that many in the news group like to trash. It's noise is 3 time
worse than the 5D, which is exactly what you'd expect since the sensor
area is 9 times smaller. And like the 5D the noise is pretty much
constant as you move down the graph

Now look at the S3IS graph. Not only is the noise not even close to
being constant, it's over 10 time worse than the 5D in the dark area
of the grey scale and 3-4 times worse that the SP350.

Note--I'd argue that since ISO numbers are just gain settings to
compare the sensor noise in cameras, you should start at lowest and X1
gain-- no matter what the marketing folks decided to call that setting
-- and count up gain steps. So my numbers are from comparing the 200
ISO graphs of the 5D and Sp350 (both cameras start at ISO50) with the
400 ISO of the S3IS. If you disagree and compare graphs labeled with
the same ISO numbers, the results are the same, just a little less
obvious.

So what going on? Since Canon does know how to make good low
noise cameras, I'm guessing the problem is caused by electrical pickup
from the piezo motors. With the sensor ouputs measured in microvolts
and the piezo motors being hit continiously at much higher voltages
the design must be a noise-engineer's nightmare.


I have three IS cameras and four IS lenses for my
DSLR. None of these types of noise has been an issue.


I wouldn't expect to see this on a DSLR using IS lens since the
piezo motors are much farther away from the sensor electronics.


Any comments?

jpc

And lo, Skip emerged from the ether
and spake thus:
"J. Clarke" wrote in message
...
On Thu, 21 Dec 2006 14:43:06 -0800, DougL wrote:

Skip wrote:
"jpc" wrote in message
...
Based on some published information from a review site, IS point and
shoot camera seem to be more noisy than non IS camera. This I'm
blaiming on electrical pickup from the piezo motors used to move
either a lens element or the sensor.

Anyone have any experience or comments on this topic

jpc

I'm guessing it's because the p&s IS cameras have "digital"
stabilization,
which, in many cases, is merely a bump up for ISO and shutter speed,
which,
of course, results in more noise...

--
Skip Middleton
www.shadowcatcherimagery.com
www.pbase.com/skipm

Exactly right, as finally concluded in this long thread over the last
two days.

http://tinyurl.com/yj7mpq

Turn it off, if you can, if you don't need it.

Note too that digital image stabilization (DIS) has neither a
stabilization sensor, nor does any image motion. Just ISO bump up,
which amplifies system noise as well. We finally concluded that calling
this IS was quite misrepresentative.

Optical image stabilization (OIS) has a tilt sensor, and a moving
mirror to shift the image.

Charge motion image stabilization has a tilt sensor, and shifts the
image digitally in the pixels electronically.

Inexpensive consumer cameras just have DIS. No sensor, no piezo motors,
no nothing.

Oh, GAWD.

First most point and shoot cameras with image stabilization have optical
image stabilization just like Canon and Nikon DSLRs. It's only the Fuji
and possibly some other other cheap POS cameras that pretend that they
do by increasing the ISO. Second, optical image stabilization does not
use a "moving mirror", one of the elements in the lens moves, those
elements all being lenses unless its a catadioptric.

--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

The Oly FE-170 I was flummoxed into buying for my daughter for Christmas has
"digital image stabilization," not an expensive camera, at $150, but from a
respected mfr.
I won't argue your other points, (moving mirror?), but some of them move the
sensor, don't they?

Some of them move the sensor, but not for $150 they don't. In-camera
mechanical image stabilization is a relatively new feature, too.

--
Aaron
http://www.fisheyegallery.com
http://www.singleservingphoto.com

jpc wrote:
[]
So what going on? Since Canon does know how to make good low
noise cameras, I'm guessing the problem is caused by electrical pickup
from the piezo motors. With the sensor ouputs measured in microvolts
and the piezo motors being hit continiously at much higher voltages
the design must be a noise-engineer's nightmare.

How does the noise you have measured compare to the pixel area?

David

On Fri, 22 Dec 2006 18:53:39 GMT, "David J Taylor"
wrote:

jpc wrote:
[]
So what going on? Since Canon does know how to make good low
noise cameras, I'm guessing the problem is caused by electrical pickup
from the piezo motors. With the sensor ouputs measured in microvolts
and the piezo motors being hit continiously at much higher voltages
the design must be a noise-engineer's nightmare.

How does the noise you have measured compare to the pixel area?

David


The 5D has a pixel area of about 70 sq microns where about 25 sq
microns of the silicon rea lestate is used by the pixel electronics
the keeps the noise so low. It has an active sensor area of about 45
sq microns.

Ths SP350 has a 5 sq micron sensor; the S3IS has a 4 sq micron sensor

So the S3IS should have slightly more noise than the SP350, but it
should be nowhere near the 3-4 times more noise in the dark areas It
the noise was photon shot noise, the only noise source where pixel
area is important, the noise would stay roughly constant as long as
the camera has a default gamma curve somewhere near 2.2.

The excess noise has to be coming from inside the camera and not from
the light entering the camera. My guess is the piezo motors, but I
maybe wrong.

If there is anyone reading this thread who owns a IS P&S and wants to
prove me wrong I have a procedure to test your camera. Just snapping
a picture with IS on and then off and eyeballing the results
will not reveal that much. Because of the physics of photon shot noise
and gamma correction, the excess noise will showup in the near total
black areas where it would be difficult to eyeball accurately

jpc

J. Clarke wrote:
On Thu, 21 Dec 2006 14:43:06 -0800, DougL wrote:

Skip wrote:
"jpc" wrote in message
...
Based on some published information from a review site, IS point and
shoot camera seem to be more noisy than non IS camera. This I'm
blaiming on electrical pickup from the piezo motors used to move
either a lens element or the sensor.

Anyone have any experience or comments on this topic

jpc

I'm guessing it's because the p&s IS cameras have "digital" stabilization,
which, in many cases, is merely a bump up for ISO and shutter speed, which,
of course, results in more noise...

--
Skip Middleton
www.shadowcatcherimagery.com
www.pbase.com/skipm

Exactly right, as finally concluded in this long thread over the last
two days.

http://tinyurl.com/yj7mpq

Turn it off, if you can, if you don't need it.

Note too that digital image stabilization (DIS) has neither a
stabilization sensor, nor does any image motion. Just ISO bump up,
which amplifies system noise as well. We finally concluded that calling
this IS was quite misrepresentative.

Optical image stabilization (OIS) has a tilt sensor, and a moving
mirror to shift the image.

Charge motion image stabilization has a tilt sensor, and shifts the
image digitally in the pixels electronically.

Inexpensive consumer cameras just have DIS. No sensor, no piezo motors,
no nothing.

Oh, GAWD.

First most point and shoot cameras with image stabilization have optical
image stabilization just like Canon and Nikon DSLRs. It's only the Fuji
and possibly some other other cheap POS cameras that pretend that they
do by increasing the ISO. Second, optical image stabilization does not
use a "moving mirror", one of the elements in the lens moves, those
elements all being lenses unless its a catadioptric.

--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

Oh gawd?

We spend several days and a lot of words trying to establish exactly
who has what. As far as the thread participants were concerned, we
ended up concluding that point and shoot cameras did NOT have OIS. Can
you supply a pointer that says otherwise?

Would be interesting to know who really does image stabilization
(either CCD-shift or optical) in a point-and-shoot.

Yes, "moving mirror" was my shorthand. "Moving optic" would have been
more accurate.

Skip wrote:
"J. Clarke" wrote in message
...
On Thu, 21 Dec 2006 14:43:06 -0800, DougL wrote:

Skip wrote:
"jpc" wrote in message
...
Based on some published information from a review site, IS point and
shoot camera seem to be more noisy than non IS camera. This I'm
blaiming on electrical pickup from the piezo motors used to move
either a lens element or the sensor.

Anyone have any experience or comments on this topic

jpc

I'm guessing it's because the p&s IS cameras have "digital"
stabilization,
which, in many cases, is merely a bump up for ISO and shutter speed,
which,
of course, results in more noise...

--
Skip Middleton
www.shadowcatcherimagery.com
www.pbase.com/skipm

Exactly right, as finally concluded in this long thread over the last
two days.

http://tinyurl.com/yj7mpq

Turn it off, if you can, if you don't need it.

Note too that digital image stabilization (DIS) has neither a
stabilization sensor, nor does any image motion. Just ISO bump up,
which amplifies system noise as well. We finally concluded that calling
this IS was quite misrepresentative.

Optical image stabilization (OIS) has a tilt sensor, and a moving
mirror to shift the image.

Charge motion image stabilization has a tilt sensor, and shifts the
image digitally in the pixels electronically.

Inexpensive consumer cameras just have DIS. No sensor, no piezo motors,
no nothing.

Oh, GAWD.

First most point and shoot cameras with image stabilization have optical
image stabilization just like Canon and Nikon DSLRs. It's only the Fuji
and possibly some other other cheap POS cameras that pretend that they
do by increasing the ISO. Second, optical image stabilization does not
use a "moving mirror", one of the elements in the lens moves, those
elements all being lenses unless its a catadioptric.

--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

The Oly FE-170 I was flummoxed into buying for my daughter for Christmas has
"digital image stabilization," not an expensive camera, at $150, but from a
respected mfr.
I won't argue your other points, (moving mirror?), but some of them move the
sensor, don't they?

--
Skip Middleton
www.shadowcatcherimagery.com
www.pbase.com/skipm

As I said, these inexpensive cameras just have DIS, and there isn't
anything moving in this "stabiliztion system". Not even electrons
between pixels.

Never heard of moving the sensor. As in moving the CCD?
Engineering-wise, that would be pretty challenging.

DougL wrote:
[]
We spend several days and a lot of words trying to establish exactly
who has what. As far as the thread participants were concerned, we
ended up concluding that point and shoot cameras did NOT have OIS. Can
you supply a pointer that says otherwise?

Would be interesting to know who really does image stabilization
(either CCD-shift or optical) in a point-and-shoot.

Yes, "moving mirror" was my shorthand. "Moving optic" would have been
more accurate.


You concluded incorrectly.

Plenty of non-SLR cameras have pure optical image stabilsation, for
example lens-based in many of the Panasonic cameras (FZ20, FZ5, FZ30,
FZ50, FZ7 and many of their compact cameras as well), and Canon S1-IS,
S2-IS, S3-IS, and Minolta have (had?) moving sensor (Z3 etc.).

Some pointers:

http://www.dpreview.com/reviews/panasonicfz20/

http://www.dpreview.com/reviews/panasonictz1/

http://www.dpreview.com/reviews/canons3is/

http://www.dpreview.com/news/0407/04070703dimagez3.asp

David

On 22 Dec 2006 12:53:21 -0800, "DougL" wrote:


Skip wrote:
"J. Clarke" wrote in message
...
On Thu, 21 Dec 2006 14:43:06 -0800, DougL wrote:

Skip wrote:
"jpc" wrote in message
...
Based on some published information from a review site, IS point and
shoot camera seem to be more noisy than non IS camera. This I'm
blaiming on electrical pickup from the piezo motors used to move
either a lens element or the sensor.

Anyone have any experience or comments on this topic

jpc

I'm guessing it's because the p&s IS cameras have "digital"
stabilization,
which, in many cases, is merely a bump up for ISO and shutter speed,
which,
of course, results in more noise...

--
Skip Middleton
www.shadowcatcherimagery.com
www.pbase.com/skipm

Exactly right, as finally concluded in this long thread over the last
two days.

http://tinyurl.com/yj7mpq

Turn it off, if you can, if you don't need it.

Note too that digital image stabilization (DIS) has neither a
stabilization sensor, nor does any image motion. Just ISO bump up,
which amplifies system noise as well. We finally concluded that calling
this IS was quite misrepresentative.

Optical image stabilization (OIS) has a tilt sensor, and a moving
mirror to shift the image.

Charge motion image stabilization has a tilt sensor, and shifts the
image digitally in the pixels electronically.

Inexpensive consumer cameras just have DIS. No sensor, no piezo motors,
no nothing.

Oh, GAWD.

First most point and shoot cameras with image stabilization have optical
image stabilization just like Canon and Nikon DSLRs. It's only the Fuji
and possibly some other other cheap POS cameras that pretend that they
do by increasing the ISO. Second, optical image stabilization does not
use a "moving mirror", one of the elements in the lens moves, those
elements all being lenses unless its a catadioptric.

--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

The Oly FE-170 I was flummoxed into buying for my daughter for Christmas has
"digital image stabilization," not an expensive camera, at $150, but from a
respected mfr.
I won't argue your other points, (moving mirror?), but some of them move the
sensor, don't they?

--
Skip Middleton
www.shadowcatcherimagery.com
www.pbase.com/skipm

As I said, these inexpensive cameras just have DIS, and there isn't
anything moving in this "stabiliztion system". Not even electrons
between pixels.

Never heard of moving the sensor. As in moving the CCD?
Engineering-wise, that would be pretty challenging.

Agree with that 100 %.

Here's my version of camera shake correction---AKA IS

Take a five foot length of light chain, attach it to a 1/4-20 bolt
and screw into the tripod mounting hole of the camera. Wrap the camera
strap around your neck and arm like it is a rifle sling. Frame your
shot, step on the chain, and pull the camera taunt.

Instant tripod.

After some practice, I been able to take some reasonable hand held
pictures with 1/4 to 1/2 exposure times. Don't know how this stacks up
against the fancier version but I bet it's in the ball park.

jpc

On 22 Dec 2006 12:53:21 -0800, "DougL" wrote:

As I said, these inexpensive cameras just have DIS, and there isn't
anything moving in this "stabiliztion system". Not even electrons
between pixels.

Never heard of moving the sensor. As in moving the CCD?
Engineering-wise, that would be pretty challenging.

"In-camera IS", as opposed to "in-lens IS", moves the sensor to
counter camera shake/movement.
There are some DSLRs that use this system.
--
Bill Funk
replace "g" with "a"

jpc wrote:
Based on some published information from a review site, IS point and
shoot camera seem to be more noisy than non IS camera. This I'm
blaiming on electrical pickup from the piezo motors used to move
either a lens element or the sensor.

Anyone have any experience or comments on this topic


Comments? Yes:
Complete ********.


--
Images (Plus Snaps & Grabs) by Mark² at:
www.pbase.com/markuson