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Image Stabilization vs Noise

 
 
Mark²
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      12-23-2006
jpc wrote:
> On Thu, 21 Dec 2006 10:44:48 -0800, Phil Wheeler <(E-Mail Removed)>
> 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.


What you're seeing has absolutely nothing whatever to do with IS.
It has to do with the sensor size, type, and the signal amplificatino
required to eek data out of much smaller sensor points. The full frame on
the 5D has comparatively HUGE points, which are naturally capable of
gathering more light...meaning less need to amplify the signal.

This is one of many reasons why small sensor point-and-shoots can't compete
with DSLRs in terms of noise adn high ISO performance. Again... NOT an IS
issue.
>
>
>> 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


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


 
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Mark²
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Posts: n/a
 
      12-23-2006
Skip wrote:
> "jpc" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
>> 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...


If he's talking about non-optical IS, then that's a different story
altogether, and has little or no relation to optical IS lenses attached to
DSLRs...

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


 
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Daniel Silevitch
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      12-23-2006
On 22 Dec 2006 12:46:57 -0800, DougL <(E-Mail Removed)> 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.


After a brief search, the cheapest camera I could find with a real
optical stabilizer (using a lens-shift system) is the Panasonic LZ3,
$160 at B&H.

Plenty of other P&Ss, from a whole slew of makers, use real mechanical
stabilizers.

-dms
 
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Daniel Silevitch
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Posts: n/a
 
      12-23-2006
On 22 Dec 2006 12:53:21 -0800, DougL <(E-Mail Removed)> 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.


Go to http://www.dpreview.com/reviews/panasoniclz2/page5.asp
and look at the sample images on that page. It's a real
lens-shift stabilizer.

This year's version of the same camera goes for about $150ish, which
definitely puts it in the 'inexpensive' category.

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


The stabilizer system that Sony inherited from Minolta is a sensor-shift
system, as is the stabilizer that Pentax uses in their DSLRs.

-dms
 
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jpc
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      12-23-2006
On Sat, 23 Dec 2006 01:50:14 -0800, "MarkĀ²" <mjmorgan(lowest even
number here)@cox..net> wrote:

>jpc wrote:
>> On Thu, 21 Dec 2006 10:44:48 -0800, Phil Wheeler <(E-Mail Removed)>
>> 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.

>
>What you're seeing has absolutely nothing whatever to do with IS.
>It has to do with the sensor size, type, and the signal amplificatino
>required to eek data out of much smaller sensor points. The full frame on
>the 5D has comparatively HUGE points, which are naturally capable of
>gathering more light...meaning less need to amplify the signal.


As I stated in my follow-up post to David Taylor the 5D has a pixel
size of ~70 sq microns and an active sensor size of ~45 sq microns.
The Oly SP350--a much underrated camerra I ended up buying--has an
active sensor size of ~5 sq microns.

Photon shot noise, Poison noise, or the random way Momma Nature tosses
light into your lens is "roughly" determined by pixel size. The real
parameter is pixel well depth--something the camera manufactures have
decided not to tell us about.

Since Momma Nature noise is determined by the sq root of the number of
photo electrons collected and the square root of 9 is 3, the SP350
has a S/N 3 time worse than the 5D in the regions where Momma Nature
noise dominates.

This is what theory predicts, this is what the data from Imaging-
resourse shows and most important to me--this is how the SP350 I
bought performed when I tested it.

So I've lost a stop and a half of signal to noise by buying a camera
that some in this group automatically trash .But since I paid 20X less
that a 5D with lens the price /performance ratio is definately in my
favor.

And of couse, I can carry around my camera outfit--camera, batteries,
cards, telephoto and wide angle extender lens, even a mini tripod-- in
my coat pocket. That's something you can not say about a 5D and its
collection of lens.

>
>This is one of many reasons why small sensor point-and-shoots can't compete
>with DSLRs in terms of noise adn high ISO performance. Again... NOT an IS
>issue.


The Imaging-resouce noise data for the S3IS does NOT follow the
theory and physics of Momma Nature noise. The noise in the dark
patches--the shadow areas in low light photography where S/N is most
important-- is 4 X worse than it should be.

From that I can draw two conclusions. The first is that image
stabization in a high end P&S is not the solution to all problems like
the camera sellers want you to believe when you plop down your $400.
The second is that the S3IS is overall a lousy camera.

So if anyone who own a IS P&S is willing to spend a couple hours of
their life to help answer this burning question, I'm willing to offer
advice and comentary. If I'm wrong, I'm wrong. But if I'm right, 2
bucks worth of chain vs 400 bucks worth of camera makes for an
excelent price/perfomance ratio


jpc










 
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David J. Littleboy
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Posts: n/a
 
      12-23-2006

"jpc" <(E-Mail Removed)> wrote:
>
> As I stated in my follow-up post to David Taylor the 5D has a pixel
> size of ~70 sq microns and an active sensor size of ~45 sq microns.
> The Oly SP350--a much underrated camerra I ended up buying--has an
> active sensor size of ~5 sq microns.
>
> Photon shot noise, Poison noise, or the random way Momma Nature tosses
> light into your lens is "roughly" determined by pixel size. The real
> parameter is pixel well depth--something the camera manufactures have
> decided not to tell us about.
>
> Since Momma Nature noise is determined by the sq root of the number of
> photo electrons collected and the square root of 9 is 3, the SP350
> has a S/N 3 time worse than the 5D in the regions where Momma Nature
> noise dominates.
>
> This is what theory predicts, this is what the data from Imaging-
> resourse shows and most important to me--this is how the SP350 I
> bought performed when I tested it.


So far so good, but...

> So I've lost a stop and a half of signal to noise by buying a camera
> that some in this group automatically trash .But since I paid 20X less
> that a 5D with lens the price /performance ratio is definately in my
> favor.


Oops. No. SNR vs. ISO stops don't work that way. An exposure at ISO 100
captures twice as many photons as ISO 200, so cutting the sensor area in
half means your ISO 100 has the same SNR ratio as the larger pixel's ISO
200. (That is, a one stop higher ISO has 1.414 times the noise, not twice
the noise.)

(The price/performance ratio is still in your favor, though<g>.)

So you've lost _more than three_ stops of SNR ratio. The 5D at ISO 800 looks
better than the P&S at ISO 100. And the 5D user has f/1.4 and f/2.0 lenses
if s/he wants, which are non-existent and rare in the P&S world nowadays.

>>This is one of many reasons why small sensor point-and-shoots can't
>>compete
>>with DSLRs in terms of noise adn high ISO performance. Again... NOT an
>>IS
>>issue.

>
> The Imaging-resouce noise data for the S3IS does NOT follow the
> theory and physics of Momma Nature noise. The noise in the dark
> patches--the shadow areas in low light photography where S/N is most
> important-- is 4 X worse than it should be.


I don't know if this is wrong (due to the above mistake) or not, but it
might be.

David J. Littleboy
Tokyo, Japan


 
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jpc
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      12-23-2006
On Sat, 23 Dec 2006 01:46:34 -0800, "MarkĀ²" <mjmorgan(lowest even
number here)@cox..net> 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

>
>
>Comments? Yes:
>Complete *******s.


See my reply above. I'm talking physics, data, and proceedures for
evaluating the data if anyone wishes to confirm what I'm saying.

I'm even willing to cheerfully admit I'm wrong if anyone can come up
with an alternate and better explanation to the conclusions I've drawn
from the data.

What more can you ask.

jpc

 
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jpc
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      12-23-2006
On Sat, 23 Dec 2006 23:44:29 +0900, "David J. Littleboy"
<(E-Mail Removed)> wrote:

>
>"jpc" <(E-Mail Removed)> wrote:
>>
>> As I stated in my follow-up post to David Taylor the 5D has a pixel
>> size of ~70 sq microns and an active sensor size of ~45 sq microns.
>> The Oly SP350--a much underrated camerra I ended up buying--has an
>> active sensor size of ~5 sq microns.
>>
>> Photon shot noise, Poison noise, or the random way Momma Nature tosses
>> light into your lens is "roughly" determined by pixel size. The real
>> parameter is pixel well depth--something the camera manufactures have
>> decided not to tell us about.
>>
>> Since Momma Nature noise is determined by the sq root of the number of
>> photo electrons collected and the square root of 9 is 3, the SP350
>> has a S/N 3 time worse than the 5D in the regions where Momma Nature
>> noise dominates.
>>
>> This is what theory predicts, this is what the data from Imaging-
>> resourse shows and most important to me--this is how the SP350 I
>> bought performed when I tested it.

>
>So far so good, but...
>
>> So I've lost a stop and a half of signal to noise by buying a camera
>> that some in this group automatically trash .But since I paid 20X less
>> that a 5D with lens the price /performance ratio is definately in my
>> favor.

>
>Oops. No. SNR vs. ISO stops don't work that way. An exposure at ISO 100
>captures twice as many photons as ISO 200, so cutting the sensor area in
>half means your ISO 100 has the same SNR ratio as the larger pixel's ISO
>200. (That is, a one stop higher ISO has 1.414 times the noise, not twice
>the noise.)


Agreed. Half the photoelectrons in the pixel well, 1.4 times more
noise
>
>(The price/performance ratio is still in your favor, though<g>.)
>
>So you've lost _more than three_ stops of SNR ratio. The 5D at ISO 800 looks
>better than the P&S at ISO 100.


Right,again. My mental miscalculation

ISO 400 (2 stops and 4X gain) gives 2X noise. ISO 800 (3 stops and 8X
gain) give 3X noise. Which is what the imaging-resource data says--a
3X noise difference between the two camera.

And the 5D user has f/1.4 and f/2.0 lenses
if s/he wants, which are non-existent and rare in the P&S world
nowadays. This is one of many reasons why small sensor
point-and-shoots can't compete with DSLRs in terms of noise adn high
ISO performance. Again... NOT an IS issue.

Agreed-partially. If we're talking about photon noise--the noise
source where sensor size is an issue--it doesn't matter is you fill
the pixel well in a 1/1000 of a second or a 1/10 off a second. The S/N
is still the same until you reach a shutter speed where thermal noise
becomes a problem.

A f1.4 lens obviously will fill the pixel well in a 1/4 the time as a
f2.8 lens under identical conditions. So my buddy's $5000 colection of
camera and lens will beat my $225 camera, it's heavy weigh vs light
weigh, but I don't think lens speeds have much to do with my question.

>>
>> The Imaging-resouce noise data for the S3IS does NOT follow the
>> theory and physics of Momma Nature noise. The noise in the dark
>> patches--the shadow areas in low light photography where S/N is most
>> important-- is 4 X worse than it should be.

>
>I don't know if this is wrong (due to the above mistake) or not, but it
>might be.


Here's my question restated. The SP350 and S3IS have roughly similar
size pixel and should have roughly 3-4X more photon noise than the 5D.
The S3!S has 10-12X more noise.

Where is the extra noise coming from?

jpc

>




 
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Skip
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Posts: n/a
 
      12-23-2006

"DougL" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) ps.com...
>
> Skip wrote:
>> "J. Clarke" <(E-Mail Removed)> wrote in message
>> news:(E-Mail Removed)...
>> > On Thu, 21 Dec 2006 14:43:06 -0800, DougL wrote:
>> >
>> >> Skip wrote:
>> >>> "jpc" <(E-Mail Removed)> wrote in message
>> >>> news:(E-Mail Removed)...
>> >>> > 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.
>

Several DSLRs have that feature, now, the Sony A100, for one.

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


 
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Skip
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      12-23-2006
<jpc> wrote in message news:(E-Mail Removed)...
> On 22 Dec 2006 12:53:21 -0800, "DougL" <(E-Mail Removed)> wrote:
>


>>
>>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
>

I've carried around a length of light nylon twine with a bolt for 20 years,
works well in a pinch, but not as well as IS or a tripod.

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


 
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