P&S vs DSLR - Does this argument make sense?

ASAAR wrote:
> Your generally pro-DSLR stance is obviously at odds with
> the anti-DSLR views of the ...

I'm not pro DSLR. I'm pro performance. The current crop
of P&S cameras have generally low performance. Shutter
lag in P&S digital camera is, in general, worse than with
P&S film cameras. Noise is higher than it needs to be.
There is no technical reason why camera manufacturers
can't make small, pocket-size cameras with virtually no
shutter lag (e.g., use the same, or an improved
AF mechanisms from film P&S cameras), with
large sensors to give good signal-to-noise
ratios, comparable to many DSLRs, and for prices
less than the current low end DSLRs. But for some reason
(fear of eroding the DSLR market?) they haven't yet
done that.

When they do, I'll buy one. From the many complaints we
continuously see about P&S digitals in this newsgroup, I bet
many other people will buy them too.
Camera manufacturers, are you listening?

That doesn't mean there isn't a market for the low performance
lowest cost digital P&S, but today, there is a performance
gap were there need not be one.

Roger
 >> Stay informed about: P&S vs DSLR - Does this argument make sense? 

Raphael Bustin wrote:
> On Sun, 29 Jul 2007 14:53:09 -0700, nospam <nospam.RemoveThis@nospam.invalid>
> wrote:
>
>> question for roger -
>>
>> according to figure 5 (page 3), the thickness of the top layer is a
>> little more than 1/8th of the total depth. does that mean the photon
>> capacity is also about 1/8th as much? if so, would that explain why
>> the blue channel is incredibly noisy on foveon images, causing the
>> color blotching?
>
> FWIW, the blue channel is often the noisiest on standard
> CCD and CMOS sensors as well. If you look at CCD data
> sheets you'll see that of the three channels, the blue chanel
> invariably has the lowest output for a given light level.
>
> rafe b
> www.terrapinphoto.com

Yes, I agree. But also, the Foveon sensor probably has lower
well capacities in each channel, probably contributing to higher noise
in all channels. The blue channel, if ~1/8 the well depth, would
be additionally challenged as well as having the lower
quantum efficiency of silicon sensors in general in the blue.
It sure would be nice to see real sensor performance data
(full well capacities and read noise for each channel) to
really understand what is going on.

Roger
 >> Stay informed about: P&S vs DSLR - Does this argument make sense? 

On Jul 29, 1:48 pm, "Roger N. Clark (change username to rnclark)"
<usern....TakeThisOut@qwest.net> wrote:
> acl wrote:
> > On Jul 28, 2:07 pm, Michael J Davis <?...@trustsof.demon.co.uk> wrote:
> >> Noons <wizofo....TakeThisOut@yahoo.com.au> observed>On Jul 27, 11:30 am, acl <achilleaslazari....TakeThisOut@yahoo.co.uk> wrote:
>
> >>> Simple: I don't take photos of atoms.
> >> I do, billions of them!
>
> >> Of course, what I really take is mostly the light bouncing off 'em.
> >> In fact, there's little in my photos that isn't atoms joined together as
> >> molecules.
>
> > Well the point I was (maybe too subtly) trying to make earlier is that
> > it's not bounced off the atoms, it is absorbed and re-emitted by them.
> > If (if!) one ponders this for a while, one hopefully concludes that a
> > photon may in fact be "detected" by something smaller than its
> > wavelength... Otherwise, eg anything thinner than 400nm would be
> > transparent, etc...
>
> All good points.
>
> There are multiple issues with small pixels and detecting photons.
> Remember that as a pixel becomes small, while photons may interact
> with the photosensitive area, they also interact with the
> surrounding material, which will also scatter (reflect) and
> absorb them. As the photosensitive area becomes much smaller
> than the wavelength, the chances of a photon being absorbed
> by the photosensitive area and not the rest of the substrate
> becomes very small. Second, the photosensitive area must be
> thick enough so that there is enough path length for the
> photon traveling through the material so it can be aborbed.
> In silicon, the 1/e depth is over 2 microns (see table below)
> at green wavelengths, so small photosensitive pixels will have lower
> quantum efficiency.
>
> Data below From:http://learn.hamamatsu.com/articles/quantumefficiency.html
>
> Wavele-
> ngth
> (Nano-
> meters) Penetration Depth
> (micrometers)
>
> 400 0.19 deep blue/violet
> 450 1.0
> 500 2.3 green (blue-green)
> 550 3.3
> 600 5.0 Red
> 650 7.6
> 700 8.5 ~upper limit of human vision
> 750 16
> 800 23
> 850 46
> 900 62
> 950 150
> 1000 470
> 1050 1500
> 1100 7600

But what evidence do we have that (for e.g.) 4/3rds with 10 megapixels
are less sensitive than 1.5 sensors with larger pixels?
 >> Stay informed about: P&S vs DSLR - Does this argument make sense? 

Roger N. Clark (change username to rnclark) wrote:

> TimothySimmers wrote:
>
>> On Sun, 29 Jul 2007 11:51:14 -0600, "Roger N. Clark (change username to
>> rnclark)" <username.TakeThisOut@qwest.net> wrote:
>>
>>> Try having someone bounce a ball in front of your
>>> "live preview" camera and note where the ball appears
>>> in the view by your eyes versus on the LCD.
>>
>>
>> Yes, there's a very slight delay in my 8 year-old digicam. None in my
>> two more
>> recent point & shooters. I can wave my hand in front of my camera as
>> fast as I
>> want and it retransmits that image to the LCD and EVF in perfect sync,
>> or at
>> least faster than I'm able to see any difference with my own senses.
>
> That's great. What models? I would like to get one for myself
> if they are really that fast.

There may be additional delay in actually capturing the image versus
what you see on the viewfinder.


>> The point
>> you were trying to make, is what? That you like promoting
>> misinformation based
>> on some minor experience that you had with decade-old technology? Or
>> that you
>> only know how to parrot what you've read elsewhere? I can now see why
>> people say
>> what they do about you. It's all true.
>
>
> Well, all the ones I own, my family owns, and all the models
> I've tested in stores show pretty significant delay, so much
> so that it is often frustrating trying to pan, especially with
> any action happening (e.g. like people at a meeting, moving
> at walking speeds; forget sports or wildlife action).
> That includes current models on the market.
>
> Please cite models that show no noticeable delay.
>
>> You're nothing but a thinly veiled troll and spam-artist whose only
>> intent is to
>> get people to your web pages to sell your profanely mundane photography.
>>
>> <PLONK>
>
>
> It seems you can't take the truth so you launch personal
> attacks, as usual.
>
> Roger


--
Paul Furman Photography
http://edgehill.net
Bay Natives Nursery
http://www.baynatives.com
 >> Stay informed about: P&S vs DSLR - Does this argument make sense? 

Rich wrote:
> On Jul 29, 1:48 pm, "Roger N. Clark (change username to rnclark)"
> <usern....DeleteThis@qwest.net> wrote:
>> acl wrote:
>>> On Jul 28, 2:07 pm, Michael J Davis <?...@trustsof.demon.co.uk> wrote:
>>>> Noons <wizofo....DeleteThis@yahoo.com.au> observed>On Jul 27, 11:30 am, acl <achilleaslazari....DeleteThis@yahoo.co.uk> wrote:
>>>>> Simple: I don't take photos of atoms.
>>>> I do, billions of them!
>>>> Of course, what I really take is mostly the light bouncing off 'em.
>>>> In fact, there's little in my photos that isn't atoms joined together as
>>>> molecules.
>>> Well the point I was (maybe too subtly) trying to make earlier is that
>>> it's not bounced off the atoms, it is absorbed and re-emitted by them.
>>> If (if!) one ponders this for a while, one hopefully concludes that a
>>> photon may in fact be "detected" by something smaller than its
>>> wavelength... Otherwise, eg anything thinner than 400nm would be
>>> transparent, etc...
>> All good points.
>>
>> There are multiple issues with small pixels and detecting photons.
>> Remember that as a pixel becomes small, while photons may interact
>> with the photosensitive area, they also interact with the
>> surrounding material, which will also scatter (reflect) and
>> absorb them. As the photosensitive area becomes much smaller
>> than the wavelength, the chances of a photon being absorbed
>> by the photosensitive area and not the rest of the substrate
>> becomes very small. Second, the photosensitive area must be
>> thick enough so that there is enough path length for the
>> photon traveling through the material so it can be aborbed.
>> In silicon, the 1/e depth is over 2 microns (see table below)
>> at green wavelengths, so small photosensitive pixels will have lower
>> quantum efficiency.
>>
>> Data below From:http://learn.hamamatsu.com/articles/quantumefficiency.html
>>
>> Wavele-
>> ngth
>> (Nano-
>> meters) Penetration Depth
>> (micrometers)
>>
>> 400 0.19 deep blue/violet
>> 450 1.0
>> 500 2.3 green (blue-green)
>> 550 3.3
>> 600 5.0 Red
>> 650 7.6
>> 700 8.5 ~upper limit of human vision
>> 750 16
>> 800 23
>> 850 46
>> 900 62
>> 950 150
>> 1000 470
>> 1050 1500
>> 1100 7600
>
> But what evidence do we have that (for e.g.) 4/3rds with 10 megapixels
> are less sensitive than 1.5 sensors with larger pixels?
>

You can start by reading papers like this one:

QE Reduction due to Pixel Vignetting in CMOS Image
Sensors, by Peter B. Catrysse et al.,
http://isl.stanford.edu/groups/elgamal/abbas_publications/C074.pdf

"It is well known that the QE of CMOS photodiodes
decreases with technology scaling due to the reduction
in junction depths and the increase in doping concentrations."

Google searches turn up other relevant reading.

Roger
 >> Stay informed about: P&S vs DSLR - Does this argument make sense? 

On Sun, 29 Jul 2007 16:44:49 -0700, Paul Furman <paul-.DeleteThis@-edgehill.net>
wrote:

>Scott W wrote:
>
>> Jeroen Wenting wrote:
>>
>>> "DHB" <yoda2k.DeleteThis@verizon.net> wrote
>>>
>>>> Clive <clive.DeleteThis@cs.com> wrote:
>>>>
>>>>> I have a Canon S3 IS and a Pentax K100D - both 6mp cameras. Some time
>>>>> ago I did some comparison shots (of the same subject). Very little to
>>>>> choose at the same exposure when I printed A4, but when I printed the
>>>>> same item at A3 - the K100D was visibly better.
>>>>>
>>>>> Same number of pixels, but bigger on the K100D - sensor size does
>>>>> make a
>>>>> difference.
>>>>
>>>> Clive,
>>>> The age old question "Does size matter?" In terms of
>>>> photographic sensors, it's not so much the physical size as it is "how
>>>> many photos can it record per unit of time!"
>>>>
>>> Wrong. Recording speed has little (though potentially some) to do with
>>> sensor size.
>>> A larger sensor makes it easier to design the channels to read out the
>>> sensor elements, but otherwise there's no inherent difference.
>>
>>
>> I believe what he might have meant to say was that size affects how many
>> photons (not photos) it can record per unit of time, which would be very
>> true.
>
>Yes, I think that was a typo. However, note that it has more to do with
>the size of the sensor than the size of the pixels. There is some
>difference with dynamic range in smaller pixels but not that much if you
>have more pixels in the same area.

Thanks for the save, yes it was a typo as I did intend to type
photons not photos.

Several things actually need to be considered & "physical
sensor size" & pixel or photo receptor site size "both" matter. In
addition so does the size & type of the micro lenses used over each
photo receptor site on the Sensor, be it CMOS or CCD.

If for example if you kept the sensor resolution fixed @ say
5MP & used a 1/2.5" physical sized sensor, the size of the micro
lenses could only be so large. If however you increased the physical
sensor size to 1/1.8", you would have more area to use larger micro
lenses since we are still keeping the resolution fixed @ 5MP.

If I recall correctly Fuji used both large & small micro
lenses on the same sensor in an effort to increase dynamic range &
overall sensitivity. This may in part be responsible for the need to
increase the physical sensor size to 1/1.7" as they did on my Fuji
(F11 @ 6.3MP).

If they increased sensor size even farther & kept the
resolution @ the same 5MP, I think it would be hard to manage photo
receptor site micro lenses because I am certain that there are
practical limits as to how large they can be before dynamic range
becomes very narrow & other optical problems get out of control.

Personally I suspect that the next sensor innovations may come
when photo receptor sites become more like the eyes of nocturnal
animals that have a light reflective coating behind their photo
receptors to allow for more photons to hit the same area. The other
possibility might be a multi layer sensor or a 3 sensor approach like
that now being used in high end video cameras.

Unless some new innovative approach is conceived by somebody
thinking way "outside the box" of conventional known methods, we are
likely to continue to see relatively minor variations of sensor
optics, electronics, hardware & firmware tweaks.

Fuji's new 1/1.6" @ 12MP sensor seems interesting but I can't
help but think it's a bit too much even for them but relative to the
completion & what "most consumers" seem to want, it might just prove
to be a very lucrative combination for them. Competition certainly is
a good thing, let's hope we have much more!

Respectfully, DHB


"To announce that there must be no criticism of the President,
or that we are to stand by the President, right or wrong,
is not only unpatriotic and servile, but is morally treasonable
to the American public."--Theodore Roosevelt, May 7, 1918
 >> Stay informed about: P&S vs DSLR - Does this argument make sense? 

DHB wrote:
> On Sun, 29 Jul 2007 16:44:49 -0700, Paul Furman <paul- DeleteThis @-edgehill.net>
> wrote:
>
>> Scott W wrote:
>>
>>> Jeroen Wenting wrote:
>>>
>>>> "DHB" <yoda2k DeleteThis @verizon.net> wrote
>>>>
>>>>> Clive <clive DeleteThis @cs.com> wrote:
>>>>>
>>>>>> I have a Canon S3 IS and a Pentax K100D - both 6mp cameras. Some time
>>>>>> ago I did some comparison shots (of the same subject). Very little to
>>>>>> choose at the same exposure when I printed A4, but when I printed the
>>>>>> same item at A3 - the K100D was visibly better.
>>>>>>
>>>>>> Same number of pixels, but bigger on the K100D - sensor size does
>>>>>> make a
>>>>>> difference.
>>>>> Clive,
>>>>> The age old question "Does size matter?" In terms of
>>>>> photographic sensors, it's not so much the physical size as it is "how
>>>>> many photos can it record per unit of time!"
>>>>>
>>>> Wrong. Recording speed has little (though potentially some) to do with
>>>> sensor size.
>>>> A larger sensor makes it easier to design the channels to read out the
>>>> sensor elements, but otherwise there's no inherent difference.
>>>
>>> I believe what he might have meant to say was that size affects how many
>>> photons (not photos) it can record per unit of time, which would be very
>>> true.
>> Yes, I think that was a typo. However, note that it has more to do with
>> the size of the sensor than the size of the pixels. There is some
>> difference with dynamic range in smaller pixels but not that much if you
>> have more pixels in the same area.
>
> Thanks for the save, yes it was a typo as I did intend to type
> photons not photos.
>
> Several things actually need to be considered & "physical
> sensor size" & pixel or photo receptor site size "both" matter. In
> addition so does the size & type of the micro lenses used over each
> photo receptor site on the Sensor, be it CMOS or CCD.
>
> If for example if you kept the sensor resolution fixed @ say
> 5MP & used a 1/2.5" physical sized sensor, the size of the micro
> lenses could only be so large. If however you increased the physical
> sensor size to 1/1.8", you would have more area to use larger micro
> lenses since we are still keeping the resolution fixed @ 5MP.
>
> If I recall correctly Fuji used both large & small micro
> lenses on the same sensor in an effort to increase dynamic range &
> overall sensitivity. This may in part be responsible for the need to
> increase the physical sensor size to 1/1.7" as they did on my Fuji
> (F11 @ 6.3MP).
>
> If they increased sensor size even farther & kept the
> resolution @ the same 5MP, I think it would be hard to manage photo
> receptor site micro lenses because I am certain that there are
> practical limits as to how large they can be before dynamic range
> becomes very narrow & other optical problems get out of control.
>
> Personally I suspect that the next sensor innovations may come
> when photo receptor sites become more like the eyes of nocturnal
> animals that have a light reflective coating behind their photo
> receptors to allow for more photons to hit the same area. The other
> possibility might be a multi layer sensor or a 3 sensor approach like
> that now being used in high end video cameras.
>
> Unless some new innovative approach is conceived by somebody
> thinking way "outside the box" of conventional known methods, we are
> likely to continue to see relatively minor variations of sensor
> optics, electronics, hardware & firmware tweaks.
>
> Fuji's new 1/1.6" @ 12MP sensor seems interesting but I can't
> help but think it's a bit too much even for them but relative to the
> completion & what "most consumers" seem to want, it might just prove
> to be a very lucrative combination for them. Competition certainly is
> a good thing, let's hope we have much more!
>
> Respectfully, DHB

There is a more fundamental physics reason than seems to be implied in this
discussion. Photons are a finite resource. In a given exposure,
there are X photons/square micron delivered to the focal plane
of any camera system. By the definition of ISO, X works out
to be, for properly metered scene, that a 20% diffuse reflectance
spot will deliver about 3200 photons per square micron to the
focal plane for ISO 200, over the green passband, regardless
of exposure, f-stop, focal length, or sensor size.

So regardless of improvements in sensor technology, larger
pixels will always collect more photons. And it is the
total of the photons counted that determine signal-to-noise ratio
and dynamic range in the best situation (photon noise limited systems).

Roger
 >> Stay informed about: P&S vs DSLR - Does this argument make sense? 

On Sun, 29 Jul 2007 20:27:39 -0600, Roger N. Clark (change username
to rnclark) wrote:

>> Your generally pro-DSLR stance is obviously at odds with
>> the anti-DSLR views of the ...
>
> I'm not pro DSLR. I'm pro performance. The current crop
> of P&S cameras have generally low performance.

That's what I meant. Not that you were unfairly pro-DSLR. I'm
sure that it was you and several others that used to speak of
"focusing on the eyes" (of birds and/or animals), and that would
have been quite impossible with any P&S I've used. Perhaps some of
the P&S models I've never handled do better, but I wouldn't want to
bet on it. For that matter, in addition to the accuracy, the AF
speed is also much better with DSLRs, which when mentioned agitates
the anti-DSLR trolls into a frenzy, and also results in the
spontaneous generation of new sock puppets, as anyone with their
eyes opened must have noticed.
 >> Stay informed about: P&S vs DSLR - Does this argument make sense? 

Roger N. Clark (change username to rnclark) wrote:

> DHB wrote:
>
>> On Sun, 29 Jul 2007 16:44:49 -0700, Paul Furman <paul- DeleteThis @-edgehill.net>
>> wrote:
>>
>>> Scott W wrote:
>>>
>>>> Jeroen Wenting wrote:
>>>>
>>>>> "DHB" <yoda2k DeleteThis @verizon.net> wrote
>>>>>
>>>>>> Clive <clive DeleteThis @cs.com> wrote:
>>>>>>
>>>>>>> I have a Canon S3 IS and a Pentax K100D - both 6mp cameras. Some
>>>>>>> time
>>>>>>> ago I did some comparison shots (of the same subject). Very
>>>>>>> little to
>>>>>>> choose at the same exposure when I printed A4, but when I printed
>>>>>>> the
>>>>>>> same item at A3 - the K100D was visibly better.
>>>>>>>
>>>>>>> Same number of pixels, but bigger on the K100D - sensor size does
>>>>>>> make a
>>>>>>> difference.
>>>>>>
>>>>>> Clive,
>>>>>> The age old question "Does size matter?" In terms of
>>>>>> photographic sensors, it's not so much the physical size as it is
>>>>>> "how
>>>>>> many photos can it record per unit of time!"
>>>>>>
>>>>> Wrong. Recording speed has little (though potentially some) to do
>>>>> with sensor size.
>>>>> A larger sensor makes it easier to design the channels to read out
>>>>> the sensor elements, but otherwise there's no inherent difference.
>>>>
>>>>
>>>> I believe what he might have meant to say was that size affects how
>>>> many photons (not photos) it can record per unit of time, which
>>>> would be very
>>>> true.
>>>
>>> Yes, I think that was a typo. However, note that it has more to do
>>> with the size of the sensor than the size of the pixels. There is
>>> some difference with dynamic range in smaller pixels but not that
>>> much if you have more pixels in the same area.
>>
>>
>> Thanks for the save, yes it was a typo as I did intend to type
>> photons not photos.
>>
>> Several things actually need to be considered & "physical
>> sensor size" & pixel or photo receptor site size "both" matter. In
>> addition so does the size & type of the micro lenses used over each
>> photo receptor site on the Sensor, be it CMOS or CCD.
>>
>> If for example if you kept the sensor resolution fixed @ say
>> 5MP & used a 1/2.5" physical sized sensor, the size of the micro
>> lenses could only be so large. If however you increased the physical
>> sensor size to 1/1.8", you would have more area to use larger micro
>> lenses since we are still keeping the resolution fixed @ 5MP.
>>
>> If I recall correctly Fuji used both large & small micro
>> lenses on the same sensor in an effort to increase dynamic range &
>> overall sensitivity. This may in part be responsible for the need to
>> increase the physical sensor size to 1/1.7" as they did on my Fuji
>> (F11 @ 6.3MP).
>>
>> If they increased sensor size even farther & kept the
>> resolution @ the same 5MP, I think it would be hard to manage photo
>> receptor site micro lenses because I am certain that there are
>> practical limits as to how large they can be before dynamic range
>> becomes very narrow & other optical problems get out of control.
>>
>> Personally I suspect that the next sensor innovations may come
>> when photo receptor sites become more like the eyes of nocturnal
>> animals that have a light reflective coating behind their photo
>> receptors to allow for more photons to hit the same area. The other
>> possibility might be a multi layer sensor or a 3 sensor approach like
>> that now being used in high end video cameras.
>>
>> Unless some new innovative approach is conceived by somebody
>> thinking way "outside the box" of conventional known methods, we are
>> likely to continue to see relatively minor variations of sensor
>> optics, electronics, hardware & firmware tweaks.
>>
>> Fuji's new 1/1.6" @ 12MP sensor seems interesting but I can't
>> help but think it's a bit too much even for them but relative to the
>> completion & what "most consumers" seem to want, it might just prove
>> to be a very lucrative combination for them. Competition certainly is
>> a good thing, let's hope we have much more!
>
> There is a more fundamental physics reason than seems to be implied in this
> discussion. Photons are a finite resource. In a given exposure,
> there are X photons/square micron delivered to the focal plane
> of any camera system. By the definition of ISO, X works out
> to be, for properly metered scene, that a 20% diffuse reflectance
> spot will deliver about 3200 photons per square micron to the
> focal plane for ISO 200, over the green passband, regardless
> of exposure, f-stop, focal length, or sensor size.
>
> So regardless of improvements in sensor technology, larger
> pixels will always collect more photons. And it is the
> total of the photons counted that determine signal-to-noise ratio
> and dynamic range in the best situation (photon noise limited systems).

Larger sensor areas (regardless of pixel count) will do pretty good.
Pixels too small for their sensor size make no sense: because large
silicon chips are expensive, it makes no sense to put small pixels
spaced apart on large sensors.

--
Paul Furman Photography
http://edgehill.net
Bay Natives Nursery
http://www.baynatives.com
 >> Stay informed about: P&S vs DSLR - Does this argument make sense? 

"Michael J Davis" <?.?@trustsof.demon.co.uk> wrote in message
news:d6DexNK4rHqGFwiB@trustsof.demon.co.uk.invalid...
> Akiralx <alex1385.TakeThisOut@blueyonder.co.uk> observed
>>
>>"Raphael Bustin" <rafeb.TakeThisOut@speakeasy.net> wrote in message
>>news:h95ga3dq4dnuc49siutmlernvgb7949t29@4ax.com...
>>> On Wed, 25 Jul 2007 19:05:32 -0700, aniramca.TakeThisOut@gmail.com wrote:
>>>
>>>>I want to buy a DSLR because it is the only type of digital camera
>>>>that has larger size sensor, not because I am looking for more
>>>>flexibility of using (and spent more money on) different types and
>>>>ranges of lenses. As long as it has a reasonable zoom lens, I am
>>>>happy.
>>>>Comments?
>>>
>>> Unfortunately, yes, that's the way it is at the moment.
>>>
>>> I went through the same gyrations shopping for my most
>>> recent P&S. I was ready to spend serious cash, but
>>> there really weren't any options. The few I found were
>>> nearly as heavy (or heavier) than an SLR. (Eg.,
>>> Lumix DLC-L1K @ $1499.)
>>
>>The L1 is a DSLR. The Sony R1 may be a good choice, a bit old now though.
>
> I was shopping for a *silent* multipurpose camera earlier this year and
> looked at the Sony R1. Really interesting camera - at the original price
> much too expensive, but it was available at around the £400 price when I
> looked. (It's now back up in the £500+ range so the price I saw may be a
> mistake). But the lens (especially 24mm eqiv) and sensor size made a lot
> of sense, but the max aperture of f4.8 at 120mm worked against it for my
> needs.
>
> I eventually decided on the Panasonic FZ50 at £299, because I needed a
> longer lens for nature and candid photography and use RAW to rescue the
> image!
>
> But as a long term M3 user, I really hate the sound an SLR makes - which
> is the quietest SLR?

As you probably know it's the mirror slapping up which makes the noise
rather than the shutter. The volume varies between SLRs - dpreview.com
often has sound recordings of the noise in its reviews.

As far as I know the new and expensive Canon 1D Mark III has a whisper mode
but I'd check the specs to confirm that.
 >> Stay informed about: P&S vs DSLR - Does this argument make sense? 

On Sun, 29 Jul 2007 22:52:44 -0600, "Roger N. Clark (change username
to rnclark)" <username.RemoveThis@qwest.net> wrote:

>
>There is a more fundamental physics reason than seems to be implied in this
>discussion. Photons are a finite resource. In a given exposure,
>there are X photons/square micron delivered to the focal plane
>of any camera system. By the definition of ISO, X works out
>to be, for properly metered scene, that a 20% diffuse reflectance
>spot will deliver about 3200 photons per square micron to the
>focal plane for ISO 200, over the green passband, regardless
>of exposure, f-stop, focal length, or sensor size.
>
>So regardless of improvements in sensor technology, larger
>pixels will always collect more photons. And it is the
>total of the photons counted that determine signal-to-noise ratio
>and dynamic range in the best situation (photon noise limited systems).
>
>Roger

Roger,
Your now well past my understanding of digital sensor
& optical knowledge, however as an E.T. I offer this analogy:

If I recall correctly, right now the best "solar cells" have
about 35% efficiency in converting light into electricity.

Photo diodes or photo transistors used in digital camera
sensor are not 100% efficient either & in a similar fashion, any
increase in their efficiency might constitute a considerable
improvement it either dynamic range & or useable ISO.

The same goes for the efficiency of "all" of the associated
electronics both on & off the photographic sensor itself.

Consider LEDs. When they 1st came out, they were not very
efficient & were initially limited to red. Now LEDa have become much
more efficient. Keep in mind that "many" principles in electronic are
reversible. For example a motor can be turned into a generator as is
true of the reverse. That being said, LEDs also work as narrow band
optical "sensors" & I often use them as dual function devices in
certain applications.

For those that don't believe this, take any LED & a volt meter
out into the light & see how well it works as a light sensor. Not
nearly as efficient as a photo diode or transistor but it does work
well enough to be useful in some applications. The point here is to
graphically illustrate that if progress can be made with LEDs, it's
proof that further progress in efficiency may yet be made with photo
diodes & transistors too.

Who knows what light sensitive device may yet be developed to
take the place of a photo diode or transistor? So the sensors of
future cameras many be very different from what we can now conceive
with known & proven technologies of today.

Yes I realize that the laws of physics are unlikely to change
but there is much about quantum physics that we have yet to understand
& @ some future point, it may play an active role in digital camera
sensor technology.

Respectfully, DHB


"To announce that there must be no criticism of the President,
or that we are to stand by the President, right or wrong,
is not only unpatriotic and servile, but is morally treasonable
to the American public."--Theodore Roosevelt, May 7, 1918
 >> Stay informed about: P&S vs DSLR - Does this argument make sense? 

DHB wrote:
> On Sun, 29 Jul 2007 22:52:44 -0600, "Roger N. Clark (change username
> to rnclark)" <username.DeleteThis@qwest.net> wrote:
>
>> There is a more fundamental physics reason than seems to be implied in this
>> discussion. Photons are a finite resource. In a given exposure,
>> there are X photons/square micron delivered to the focal plane
>> of any camera system. By the definition of ISO, X works out
>> to be, for properly metered scene, that a 20% diffuse reflectance
>> spot will deliver about 3200 photons per square micron to the
>> focal plane for ISO 200, over the green passband, regardless
>> of exposure, f-stop, focal length, or sensor size.
>>
>> So regardless of improvements in sensor technology, larger
>> pixels will always collect more photons. And it is the
>> total of the photons counted that determine signal-to-noise ratio
>> and dynamic range in the best situation (photon noise limited systems).
>>
>> Roger
>
> Roger,
> Your now well past my understanding of digital sensor
> & optical knowledge, however as an E.T. I offer this analogy:
>
> If I recall correctly, right now the best "solar cells" have
> about 35% efficiency in converting light into electricity.

There are two things that make the 35% efficiency in solar cells not
apply to a camera's sensor, one is that the 35% is for the whole
spectrum of sunlight, going into the inferred and ultraviolet, neither
of which you want to capture with a cameras sensor. The other is that
for a camera sensor a captured photon is a captured photon and we don't
need to worry about what voltage it produces when captured. In a solar
cell the working voltage needs to be low enough to allow capturing long
wavelengths, which means much of the energy of the shorter wavelengths
is lost. In a camera we are not after energy just electrons.

For sensors we talk about quantum efficiency, how many electrons do we
get per photon. Within the visible area of light and given the color
filter in front of the CCD/CMOS sensors the quantum efficiency is
currently not all that bad.

There are games that can be played with changing the filters to improve
things, Kodak (if I am remembering right) is working on a sensor with
half the sensors not having any color filters in front of them at all,
and from there test images it looks like this may have some advantages.

Scott
 >> Stay informed about: P&S vs DSLR - Does this argument make sense? 

DHB wrote:
> On Sun, 29 Jul 2007 22:52:44 -0600, "Roger N. Clark (change username
> to rnclark)" <username.DeleteThis@qwest.net> wrote:
>
>> There is a more fundamental physics reason than seems to be implied in this
>> discussion. Photons are a finite resource. In a given exposure,
>> there are X photons/square micron delivered to the focal plane
>> of any camera system. By the definition of ISO, X works out
>> to be, for properly metered scene, that a 20% diffuse reflectance
>> spot will deliver about 3200 photons per square micron to the
>> focal plane for ISO 200, over the green passband, regardless
>> of exposure, f-stop, focal length, or sensor size.
>>
>> So regardless of improvements in sensor technology, larger
>> pixels will always collect more photons. And it is the
>> total of the photons counted that determine signal-to-noise ratio
>> and dynamic range in the best situation (photon noise limited systems).
>>
>> Roger
>
> Roger,
> Your now well past my understanding of digital sensor
> & optical knowledge, however as an E.T. I offer this analogy:
>
> If I recall correctly, right now the best "solar cells" have
> about 35% efficiency in converting light into electricity.
>
> Photo diodes or photo transistors used in digital camera
> sensor are not 100% efficient either & in a similar fashion, any
> increase in their efficiency might constitute a considerable
> improvement it either dynamic range & or useable ISO.
>
> The same goes for the efficiency of "all" of the associated
> electronics both on & off the photographic sensor itself.
>
> Consider LEDs. When they 1st came out, they were not very
> efficient & were initially limited to red. Now LEDa have become much
> more efficient. Keep in mind that "many" principles in electronic are
> reversible. For example a motor can be turned into a generator as is
> true of the reverse. That being said, LEDs also work as narrow band
> optical "sensors" & I often use them as dual function devices in
> certain applications.
>
> For those that don't believe this, take any LED & a volt meter
> out into the light & see how well it works as a light sensor. Not
> nearly as efficient as a photo diode or transistor but it does work
> well enough to be useful in some applications. The point here is to
> graphically illustrate that if progress can be made with LEDs, it's
> proof that further progress in efficiency may yet be made with photo
> diodes & transistors too.
>
> Who knows what light sensitive device may yet be developed to
> take the place of a photo diode or transistor? So the sensors of
> future cameras many be very different from what we can now conceive
> with known & proven technologies of today.
>
> Yes I realize that the laws of physics are unlikely to change
> but there is much about quantum physics that we have yet to understand
> & @ some future point, it may play an active role in digital camera
> sensor technology.
>
> Respectfully, DHB
>
>
> "To announce that there must be no criticism of the President,
> or that we are to stand by the President, right or wrong,
> is not only unpatriotic and servile, but is morally treasonable
> to the American public."--Theodore Roosevelt, May 7, 1918

Ahhh, yes, that quantum sensor, used to take pictures today of
tomorrow's car race. Get your bets down!
Grin.
 >> Stay informed about: P&S vs DSLR - Does this argument make sense?