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I have tested a Canon Powershot A520 and an Olympus Camedia C4000Z.
They're both 4MP and the characteristics are quite the same. I noted
the Canon has a lot of noise when the ISO is set at 400. The Olympus
shows a better response. I noted in the past the same problem comparing
other types of Powershot and Camedia cameras. The sensor is a CCD type
for the two cameras and I think the properties should be the same (for
that level of cameras).
What's the problem with Canon?
(I tested also a Canon 350D with a CMOS sensor and the noise is very
low even at 1600 ISO)

"massimo" <> wrote in message news: oups.com...
> I have tested a Canon Powershot A520 and an Olympus Camedia C4000Z.
> They're both 4MP and the characteristics are quite the same.

The C4000Z retailed for $500 while the A520 retails for about
half as much. Better optics and noise handling = higher cost.
E.g.:
C4000Z: 1/1.8" sensor.
A520: 1/2.5" sensor.

> I noted
> the Canon has a lot of noise when the ISO is set at 400. The Olympus
> shows a better response. I noted in the past the same problem comparing
> other types of Powershot and Camedia cameras. The sensor is a CCD type
> for the two cameras and I think the properties should be the same (for
> that level of cameras).
> What's the problem with Canon?

The unfortunate trend now for point-and-shoot cameras (not
just with Canon by the way) is toward putting more MP on
smaller sensors, with resulting cruddy image quality, smaller
signal-to-noise ratios etc. Each successive generation of
models is cruddier than the last.

> (I tested also a Canon 350D with a CMOS sensor and the noise is very
> low even at 1600 ISO)

Yep.

massimo wrote:
>
> I have tested a Canon Powershot A520 and an Olympus Camedia C4000Z.
> They're both 4MP and the characteristics are quite the same. I noted
> the Canon has a lot of noise when the ISO is set at 400. The Olympus
> shows a better response. I noted in the past the same problem comparing
> other types of Powershot and Camedia cameras. The sensor is a CCD type
> for the two cameras and I think the properties should be the same (for
> that level of cameras).
> What's the problem with Canon?
> (I tested also a Canon 350D with a CMOS sensor and the noise is very
> low even at 1600 ISO)

sorry, but my Olympus c-725 is as noisy as hell at 400 ISO and 200 is
pretty awful too

--
Paul (And I'm, like, "yeah, whatever!")
-------------------------------------------------------
Stop and Look
http://www.geocities.com/dreamst8me/

Tom S wrote:

> The unfortunate trend now for point-and-shoot cameras (not
> just with Canon by the way) is toward putting more MP on
> smaller sensors, with resulting cruddy image quality, smaller
> signal-to-noise ratios etc. Each successive generation of
> models is cruddier than the last.
>
> > (I tested also a Canon 350D with a CMOS sensor and the noise is very
> > low even at 1600 ISO)
>
> Yep.

This is an interesting point. But shops online don't always give
sensor size etc

In a point and shoot of varying pixels say, 2 mp to 6mp what kind of
sensor sizes are best? (Or should I say what should I look out for?)

Would 3,000,000 on a 1/2.5" CCD be better or worse than 2,000,000 0n a
1/3.2"?

--
Paul (And I'm, like, "yeah, whatever!")
-------------------------------------------------------
Stop and Look
http://www.geocities.com/dreamst8me/

"massimo" <> wrote in message
news: oups.com...
>I have tested a Canon Powershot A520 and an Olympus Camedia C4000Z.
> They're both 4MP and the characteristics are quite the same. I noted
> the Canon has a lot of noise when the ISO is set at 400. The Olympus
> shows a better response. I noted in the past the same problem comparing
> other types of Powershot and Camedia cameras. The sensor is a CCD type
> for the two cameras and I think the properties should be the same (for
> that level of cameras).
> What's the problem with Canon?
> (I tested also a Canon 350D with a CMOS sensor and the noise is very
> low even at 1600 ISO)
>

While they have the same pixel count, the sensor in the Canon A520 is
smaller than the Olympus (1/2.5" vs. 1/1.8"). So it's not a Canon issue,
just sensor size. Sensor size has a large affect on noise, that's why DSLRs
perform so well at high ISO.

Mark

"Paul Heslop" <> wrote in message news:...
> Tom S wrote:
>
> > The unfortunate trend now for point-and-shoot cameras (not
> > just with Canon by the way) is toward putting more MP on
> > smaller sensors, with resulting cruddy image quality, smaller
> > signal-to-noise ratios etc. Each successive generation of
> > models is cruddier than the last.
> >
> > > (I tested also a Canon 350D with a CMOS sensor and the noise is very
> > > low even at 1600 ISO)
> >
> > Yep.
>
> This is an interesting point. But shops online don't always give
> sensor size etc
>
> In a point and shoot of varying pixels say, 2 mp to 6mp what kind of
> sensor sizes are best? (Or should I say what should I look out for?)
>
> Would 3,000,000 on a 1/2.5" CCD be better or worse than 2,000,000 0n a
> 1/3.2"?

These things aren't written in stone. Sensor technology is
always "improving", or so we're told, but what's actually
happening is that camera manufacturers are finding ways to
mask noise problems at higher ISOs. If you'll be doing a
lot of shooting at these ISOs a dSLR is the only way to go.

Tom S wrote:
>
> "Paul Heslop" <> wrote in message news:...
> > Tom S wrote:

> These things aren't written in stone. Sensor technology is
> always "improving", or so we're told, but what's actually
> happening is that camera manufacturers are finding ways to
> mask noise problems at higher ISOs. If you'll be doing a
> lot of shooting at these ISOs a dSLR is the only way to go.

My newest one, the c-275 if left to its own devices keeps defaulting
to the grotty 200 ISO and then takes bad pictures. It can do a
reasonable job for some of the time if you remember to take a few
shots of your subject but it's painful, to say the least
--
Paul (And I'm, like, "yeah, whatever!")
-------------------------------------------------------
Stop and Look
http://www.geocities.com/dreamst8me/

"Tom S" wrote >
> These things aren't written in stone. Sensor technology is
> always "improving", or so we're told, but what's actually
> happening is that camera manufacturers are finding ways to
> mask noise problems at higher ISOs.
>

The announcements of new models seem to support your argument. It will be
interesting to see if the about to be released Fuji (I forget the model
name) S9000/S9500 will work as advertised at 1600 ISO! I read the
pre-release and it did say that this model has improved software smoothing
for lower noise at higher ISO levels. If successful it could be the 'real'
start towards making dSLR obsolete for all except the career Pro
Photographers.

I said 'START' Skip M. LOL.

Take care,
Linda

"Mark B." <> wrote in message
news:SYadnSFjnoVWA5DeRVn-...
> "massimo" <> wrote in message
> news: oups.com...
> >I have tested a Canon Powershot A520 and an Olympus Camedia C4000Z.
> > They're both 4MP and the characteristics are quite the same. I noted
> > the Canon has a lot of noise when the ISO is set at 400. The Olympus
> > shows a better response. I noted in the past the same problem comparing
> > other types of Powershot and Camedia cameras. The sensor is a CCD type
> > for the two cameras and I think the properties should be the same (for
> > that level of cameras).
> > What's the problem with Canon?
> > (I tested also a Canon 350D with a CMOS sensor and the noise is very
> > low even at 1600 ISO)
> >
>
> While they have the same pixel count, the sensor in the Canon A520 is
> smaller than the Olympus (1/2.5" vs. 1/1.8"). So it's not a Canon issue,
> just sensor size. Sensor size has a large affect on noise, that's why
DSLRs
> perform so well at high ISO.
>
> Mark
>
>
I wonder what Fuji's doing with the F10? Noise performance is half way into
dSLR territory. At ISO 400, noise is very reduced and it does not look like
the image has been blurred from heavy noise reduction routines.
-S

On Thu, 25 Aug 2005 10:12:15 GMT, Paul Heslop wrote:

>
> This is an interesting point. But shops online don't always give
> sensor size etc

Manufacturer's websites sometimes provide that information as well
as review websites such as dpreview.com. Their reviews, however,
don't cover all models, and can sometimes only show up many months
or a year after the cameras are introduced.


> In a point and shoot of varying pixels say, 2 mp to 6mp what kind of
> sensor sizes are best? (Or should I say what should I look out for?)
>
> Would 3,000,000 on a 1/2.5" CCD be better or worse than 2,000,000 0n a
> 1/3.2"?

Sad to say, but even the 1/2.5" and 1/3.2" spec's are fantasy
figures, but they're good enough to be used for comparative
purposes, since then it wouldn't matter if 1/2.5" was the horizontal
dimension, the vertical, the diagonal or something else. So, for
example, multiply them by 10 to get easier numbers to deal with.
You now have sensors that have dimensions of 4" and 3.125". Fudge a
little more and say that the sensors are square, and so the areas
would be 16 and 9.8 square inches. Since the ratio (16/9. is
1.63, which is greater than the ration of pixels (3mp/2mp == 1.5),
the 3mp sensor doesn't pack the pixels as tightly (people here tend
to refer to "pixel pitch"). So there's a chance, not a guarantee,
that the pixels will be slightly larger and therefore better for
higher ISO use. In this case the numbers are so close that there'd
probably be no noticeable difference, unless other factors intrude.

It would be nice if real lengths and widths were given, since that
would make them easier to compare with other sensors with known
dimensions, such as the APS-C and 24mm x 36mm FF sensors.