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

Scott W wrote:
DHB wrote:
On Sun, 29 Jul 2007 22:52:44 -0600, "Roger N. Clark (change username
to rnclark)" 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
I think that is about 1/4 of the sensors, such that each color triad has
a sensor element that just reads the illumination level. By blending
that into the bayer sensor's output, much improvement should be
possible. I look forward to seeing how well that works.

In article , Roger N. Clark (change username
to rnclark) says...

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.

I framed a clock with an Olympus 8080 P&S. The clock is a quartz clock
with a clearly identifiable sound ("tac .. tac .. tac"), in sync with
the movement of the second hand.

The sound of the second hand was perfectly in sync with the video in the
LCD screen (i.e. the second hand moving). If there is a delay, it must
be minimal, perhaps below 0.1 seconds.

Then I repeated the test with a Sony R1, another camera with live
preview. Again no noticeable delay, even the vibrations of the second
hand were visible.

Lastly I tried out the Olympus mju 700 tiny compact of my wife. Again no
noticeable delay.
--

Alfred Molon
------------------------------
Olympus 50X0, 7070, 8080, E3X0, E4X0 and E5X0 forum at
http://tech.groups.yahoo.com/group/MyOlympus/
http://myolympus.org/ photo sharing site

On Mon, 30 Jul 2007 21:55:47 GMT, D-Rexter wrote:

They automatically or intentionally twist this shutter-speed-matching
advantage of EVF/LCD displays into their last-century thinking that
this must be some defect. Or more commonly the only time they've
ever held a P&S camera is indoors where a slow shutter-speed is
automatically chosen for them. They mistakenly (or purposely)
assume that the EVF perfectly matching the chosen shutter-speed must
be a defective 1/5th or 1/10th second display-lag. They never see that the
EVF/LCD will keep in perfect sync under normal shooting circumstances
and average shutter-speeds. I suspect this is why Roger N. Clark
doesn't know any better and can't find one that works to his liking. He's
never had enough experience with them to realize he doesn't know one
thing about P&S cameras nor even how to use them correctly. His mind
is still stuck in last-century's SLR methodology and hardware with its
inherent drawbacks and limitations. His mind just can't make the leap
to present-day technology with its many imaging and preview advantages.

If you choose a shutter speed as fast or faster than your EVF/LCD refresh
rate, which on most P&S cameras is 60 to 160 fps, the most amount of lag
you will ever get is 1/60th or 1/160th of a second. If people who have only
used SLRs and d-SLRs think that they are going to miss a photo due to a
1/60th of a second lag then they have some serious psychological issues,
blatant agendas, or don't know a thing about human-response times. Their
own nerve reactions can't even compensate for speeds that fast. Even their
eyes alone can't respond that fast.
This is why video is often delivered at 30 fps, it is beyond the abilities of
human nervous system to see individual frames.

Ergo: any "display lag" that they constantly perceive on the EVF/LCD
displays of P&S cameras is directly proportional to their "experience lag"
, "brain lag" or "intelligence lag". More often it is a combination of all
three types of lag.

New sock puppet alert! The latest list :

**** CHDK / Photoline 32 / anti-DSLR Sock Puppet Troll List ****

Baumbadier, Brad M, Bucky, CharleiD, CoolGuy, DOCJohnson,
D-Rexter, EdBancroft, , Fed-Up-With-Corel,
FrankLM, GilfordBrimly, GoKiting, HokusPokus, JoeBS, Lurk,
NameHere, NameThere, New2_S3, , RockyZ,
SayWhat, SelfImporantName, SelfImportantName, Soujourner,
spamless, TryinToHelp, WillyWonka and X-Man.

Ron Hunter wrote:
Scott W wrote:
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
I think that is about 1/4 of the sensors, such that each color triad has
a sensor element that just reads the illumination level. By blending
that into the bayer sensor's output, much improvement should be
possible. I look forward to seeing how well that works.

I found the link to an it, looks like 1/2 of the sensors have no filter
in front of them.
http://www.dpreview.com/news/0706/07...akhighsens.asp
It looks like a pretty good idea. We will have to wait and see just how
well it works in real life. Will it be as good as a standard Bayer
pattern in bright light for example.

Scott

DHB wrote:
On Sun, 29 Jul 2007 22:52:44 -0600, "Roger N. Clark (change username
to rnclark)" 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

It seems you have missed my point. The number of photons/square
micron in the focal plane is independent of the sensor. Nor does it
include the IR filter, Bayer filter, or blur filter. It is the
number of photons delivered to the focal plane by a lens.
It has nothing to do with quantum efficiency. The point is that
the photon density is a finite number. You can't increase it
(again this is the definition of proper exposure). You can't
create additional photons. The simple fact that this number is
finite means that a larger bucket (larger photo sensor) collects
more photons than a smaller one.

Side note: some CCDs have 90% quantum efficiency (QE). New CCD and CMOS
consumer digital cameras run 30 to 50% QE. Even if QE increased,
larger photo sites will collect more photons. Also, elsewhere in this
thread I posted links to an article that illustrates QE decreases
with smaller pixel size.

Second side note:
I love your Roosevelt quote--I saved it a couple of years ago.

Further reading:

Digital Cameras: Does Pixel Size Matter?
Factors in Choosing a Digital Camera
http://www.clarkvision.com/imagedeta...el.size.matter

Digital Cameras: Does Pixel Size Matter?
Part 2: Example Images using Different Pixel Sizes
http://www.clarkvision.com/imagedeta...l.size.matter2

http://www.clarkvision.com/imagedeta...rmance.summary

Roger

D-Rexter wrote:
On Mon, 30 Jul 2007 22:42:12 +0200, Alfred Molon wrote:

In article , Roger N. Clark (change username
to rnclark) says...

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.
I framed a clock with an Olympus 8080 P&S. The clock is a quartz clock
with a clearly identifiable sound ("tac .. tac .. tac"), in sync with
the movement of the second hand.

The sound of the second hand was perfectly in sync with the video in the
LCD screen (i.e. the second hand moving). If there is a delay, it must
be minimal, perhaps below 0.1 seconds.

Then I repeated the test with a Sony R1, another camera with live
preview. Again no noticeable delay, even the vibrations of the second
hand were visible.

Lastly I tried out the Olympus mju 700 tiny compact of my wife. Again no
noticeable delay.

You will find that on nearly *all* P&S cameras today that the display delay is
directly proportional to the shutter-speed selected. The EVF/LCD display in all
P&S cameras correctly depicts the shutter-speed in use. For example if you
wanted to do a motion-blur photo of a waterfall, rapids, or trickling water. You
could dial-in a slow shutter-speed and your EVF/LCD will accurately depict the
exact motion-blur effect that you want to achieve. The moving water in your
EVF/LCD blurred with the same amount as will appear on your final image. Any
delay that people report in P&S camera displays are unaware of this advanced
ability of EVF capable cameras--the EVF *perfectly* matching the image that you
will get at whatever shutter-speeds and f/stops you select. The DOF also
automatically relayed to the EVF without having to press any awkward DOF-preview
buttons that dims the image so much that it is useless, as what happens on all
SLR and d-SLR designs.

They automatically or intentionally twist this shutter-speed-matching advantage
of EVF/LCD displays into their last-century thinking that this must be some
defect. Or more commonly the only time they've ever held a P&S camera is indoors
where a slow shutter-speed is automatically chosen for them. They mistakenly (or
purposely) assume that the EVF perfectly matching the chosen shutter-speed must
be a defective 1/5th or 1/10th second display-lag. They never see that the
EVF/LCD will keep in perfect sync under normal shooting circumstances and
average shutter-speeds. I suspect this is why Roger N. Clark doesn't know any
better and can't find one that works to his liking. He's never had enough
experience with them to realize he doesn't know one thing about P&S cameras nor
even how to use them correctly. His mind is still stuck in last-century's SLR
methodology and hardware with its inherent drawbacks and limitations. His mind
just can't make the leap to present-day technology with its many imaging and
preview advantages.

If you choose a shutter speed as fast or faster than your EVF/LCD refresh rate,
which on most P&S cameras is 60 to 160 fps, the most amount of lag you will ever
get is 1/60th or 1/160th of a second. If people who have only used SLRs and
d-SLRs think that they are going to miss a photo due to a 1/60th of a second lag
then they have some serious psychological issues, blatant agendas, or don't know
a thing about human-response times. Their own nerve reactions can't even
compensate for speeds that fast. Even their eyes alone can't respond that fast.
This is why video is often delivered at 30 fps, it is beyond the abilities of
human nervous system to see individual frames.

Ergo: any "display lag" that they constantly perceive on the EVF/LCD displays of
P&S cameras is directly proportional to their "experience lag", "brain lag" or
"intelligence lag". More often it is a combination of all three types of lag.

Well, in any P&S I tested, I see no effect of LCD delay
versus shutter speed, in any mode from P to shutter to aperture
priority, from bright outside light to dim room light, from
exposure times from 10 seconds to 1/400 second. LCD delay
remains the same. Typical delays seems to be about 0.1 second.
To me this is too long, especially when you add the typical
shutter lag P&S cameras have. Full press shutter lag in
good DSLRs is under 70 milliseconds, and that includes true
zero delay from the optical viewfinder.

Please cite specific models that do this, because clearly not
all do this. You also have yet to cite P&S models that have
LCD "live preview" in "perfect sync" with as fast as you can move
your hand in front of the camera.

A real world test from last Friday:
70+ P&S cameras versus 4 DSLRs on a whale viewing boat.
Guess which cameras got pictures of a whale breaching?
Hint: guess which cameras where hindered by too much delay?

Roger

Roger N. Clark (change username to rnclark) wrote:
D-Rexter wrote:
On Mon, 30 Jul 2007 22:42:12 +0200, Alfred Molon wrote:

In article , Roger N. Clark (change
username to rnclark) says...

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.
I framed a clock with an Olympus 8080 P&S. The clock is a quartz
clock with a clearly identifiable sound ("tac .. tac .. tac"), in
sync with the movement of the second hand.

The sound of the second hand was perfectly in sync with the video in
the LCD screen (i.e. the second hand moving). If there is a delay, it
must be minimal, perhaps below 0.1 seconds.

Then I repeated the test with a Sony R1, another camera with live
preview. Again no noticeable delay, even the vibrations of the second
hand were visible.
Lastly I tried out the Olympus mju 700 tiny compact of my wife. Again
no noticeable delay.

You will find that on nearly *all* P&S cameras today that the display
delay is
directly proportional to the shutter-speed selected. The EVF/LCD
display in all
P&S cameras correctly depicts the shutter-speed in use. For example if
you
wanted to do a motion-blur photo of a waterfall, rapids, or trickling
water. You
could dial-in a slow shutter-speed and your EVF/LCD will accurately
depict the
exact motion-blur effect that you want to achieve. The moving water in
your
EVF/LCD blurred with the same amount as will appear on your final
image. Any
delay that people report in P&S camera displays are unaware of this
advanced
ability of EVF capable cameras--the EVF *perfectly* matching the image
that you
will get at whatever shutter-speeds and f/stops you select. The DOF also
automatically relayed to the EVF without having to press any awkward
DOF-preview
buttons that dims the image so much that it is useless, as what
happens on all
SLR and d-SLR designs.

They automatically or intentionally twist this shutter-speed-matching
advantage
of EVF/LCD displays into their last-century thinking that this must be
some
defect. Or more commonly the only time they've ever held a P&S camera
is indoors
where a slow shutter-speed is automatically chosen for them. They
mistakenly (or
purposely) assume that the EVF perfectly matching the chosen
shutter-speed must
be a defective 1/5th or 1/10th second display-lag. They never see that
the
EVF/LCD will keep in perfect sync under normal shooting circumstances and
average shutter-speeds. I suspect this is why Roger N. Clark doesn't
know any
better and can't find one that works to his liking. He's never had enough
experience with them to realize he doesn't know one thing about P&S
cameras nor
even how to use them correctly. His mind is still stuck in
last-century's SLR
methodology and hardware with its inherent drawbacks and limitations.
His mind
just can't make the leap to present-day technology with its many
imaging and
preview advantages.

If you choose a shutter speed as fast or faster than your EVF/LCD
refresh rate,
which on most P&S cameras is 60 to 160 fps, the most amount of lag you
will ever
get is 1/60th or 1/160th of a second. If people who have only used
SLRs and
d-SLRs think that they are going to miss a photo due to a 1/60th of a
second lag
then they have some serious psychological issues, blatant agendas, or
don't know
a thing about human-response times. Their own nerve reactions can't even
compensate for speeds that fast. Even their eyes alone can't respond
that fast.
This is why video is often delivered at 30 fps, it is beyond the
abilities of
human nervous system to see individual frames.

Ergo: any "display lag" that they constantly perceive on the EVF/LCD
displays of
P&S cameras is directly proportional to their "experience lag", "brain
lag" or
"intelligence lag". More often it is a combination of all three types
of lag.

Well, in any P&S I tested, I see no effect of LCD delay
versus shutter speed, in any mode from P to shutter to aperture
priority, from bright outside light to dim room light, from
exposure times from 10 seconds to 1/400 second. LCD delay
remains the same. Typical delays seems to be about 0.1 second.
To me this is too long, especially when you add the typical
shutter lag P&S cameras have. Full press shutter lag in
good DSLRs is under 70 milliseconds, and that includes true
zero delay from the optical viewfinder.

Please cite specific models that do this, because clearly not
all do this. You also have yet to cite P&S models that have
LCD "live preview" in "perfect sync" with as fast as you can move
your hand in front of the camera.

A real world test from last Friday:
70+ P&S cameras versus 4 DSLRs on a whale viewing boat.
Guess which cameras got pictures of a whale breaching?
Hint: guess which cameras where hindered by too much delay?

A whale breaching is slow enough that if you know it is going to happen
it is pretty easy to capture with even a slow P&S camera. These are
some I shot with a small waterproof P&S.
http://www.pbase.com/konascott/whale
The whale gets enough hang time that I was waiting, trying to hit the
shutter at the best time.

The big difference is that if I had my DSLR I would have gotten 3-4
shots / breach instead of one. And if you don't know the whale is going
to breach before hand (often the case) the chances of getting it with a
P&S are close to zero, with a DSLR you have a much better chance.

Note that when I was using the P&S auto-focus time was not an issue
because I set the focus to infinity and just left it there, if I tried
to auto-focus all you would see is a splash left over from where the
whale went in, I have a number of photos like this.

Sadly I have yet to be very close to a breaching whale with my DSLR in
hand, I don't take it out on the water with me.

Scott

"Roger N. Clark (change username to rnclark)"
wrote in message ...

A real world test from last Friday:
70+ P&S cameras versus 4 DSLRs on a whale viewing boat.
Guess which cameras got pictures of a whale breaching?
Hint: guess which cameras where hindered by too much delay?

Roger


A real world test from today:
A "group" of 1-photographer was out all day with his high-quality P&S
camera taking photos of birds in flight and other fast-action nature
photography without missing a beat, as is his custom most every day.
500 wannabe photographers were posting in newsgroups trying to
convince other wannabe photographers which is the better camera, as is
their custom 24-7-52.
Guess which group actually got any photos worthy of being called
photography this year?

Hint: tomes of typing speak more about a person's photography
experience and skills than anything they might actually say in those
words. A few photos on a web page done 10 years ago does not a life of
experience, nor wisdom, nor an authority make.

I for one will pass on your (cough) "sage" advice.

Here's an imaginary photo taken with a lowly and slow-as-snails P&S
camera in the hands of a photographer that actually knows what he's
doing .... HAND-HELD, available light (no flash), with +7 diopters
worth of close-up lens on front, at 164mm (35mm eq.) focal length.
This insect in-flight is less than 1/3" long. (6-7mm to be more exact)

http://farm2.static.flickr.com/1234/...eeda45fe_o.jpg

I guess if my P&S camera didn't have as much display lag as someone
claims they all have, I might have actually gotten this photo. I sure
hated missing getting this one due to display and shutter lag. Maybe I
should spend my money on a dSLR so I won't miss shots like this one
next time.

Ignore that shallow DOF, that's also a figment of your imagination.
Only dSLR's are capable of having a shallow DOF, any dSLR owner will
tell you that.



For the rest of you, don't buy into all this blatant misinformation
about P&S cameras. It's just uneducated and inexperienced bias being
posted in this group by people with an obvious agenda against any
camera they didn't personally choose for their own equipment. Only
their camera is the best one, they did after-all spend that much money
on it. At that much cost it has to be the best camera. Right? (more
coughing)

Scott W wrote:
Roger N. Clark (change username to rnclark) wrote:
A real world test from last Friday:
70+ P&S cameras versus 4 DSLRs on a whale viewing boat.
Guess which cameras got pictures of a whale breaching?
Hint: guess which cameras where hindered by too much delay?

A whale breaching is slow enough that if you know it is going to happen
it is pretty easy to capture with even a slow P&S camera. These are
some I shot with a small waterproof P&S.
http://www.pbase.com/konascott/whale
The whale gets enough hang time that I was waiting, trying to hit the
shutter at the best time.

The big difference is that if I had my DSLR I would have gotten 3-4
shots / breach instead of one. And if you don't know the whale is going
to breach before hand (often the case) the chances of getting it with a
P&S are close to zero, with a DSLR you have a much better chance.

Note that when I was using the P&S auto-focus time was not an issue
because I set the focus to infinity and just left it there, if I tried
to auto-focus all you would see is a splash left over from where the
whale went in, I have a number of photos like this.

Sadly I have yet to be very close to a breaching whale with my DSLR in
hand, I don't take it out on the water with me.

http://www.clarkvision.com/galleries...3556b-800.html

Out of the 70+ P&S cameras on board, none got the shot.
Of the 4 DSLRs, 2 people were chimping and missed it.
The two images were the one above and one by a guy with a Nikon DSLR.
We had no warning, only knew a breach was possible anytime, anywhere.
My main regret is I didn't take my 1D Mark II with me (I was traveling
light and didn't plan on doing this).

Roger