Dynamic range of digital and film: new data

Roger N. Clark (change username to rnclark) wrote:
[]
Yes, I'll include log-log. Both plots are useful and separate the
curves in different regions.

Roger

Thanks, Roger. David

Roger N. Clark (change username to rnclark) wrote:
[]
Yes, I'll include log-log. Both plots are useful and separate the
curves in different regions.

Roger

Thanks, Roger. David

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

I've been running tests and have some interesting new plots
of film and digital dynamic range. This is the first of about
10 graphs on this page, but I though I would share it for comments
while I built the rest of the page. See:

http://clarkvision.com/imagedetail/dynamicrange2



I can't wait to see the rest.

It seems to indicate that there might not be a lot of room for improvement
in top end CCDs.

Bob

--
Delete the inverse SPAM to reply

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

I've been running tests and have some interesting new plots
of film and digital dynamic range. This is the first of about
10 graphs on this page, but I though I would share it for comments
while I built the rest of the page. See:

http://clarkvision.com/imagedetail/dynamicrange2



I can't wait to see the rest.

It seems to indicate that there might not be a lot of room for improvement
in top end CCDs.

Bob

--
Delete the inverse SPAM to reply

bob wrote:

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


I've been running tests and have some interesting new plots
of film and digital dynamic range. This is the first of about
10 graphs on this page, but I though I would share it for comments
while I built the rest of the page. See:

http://clarkvision.com/imagedetail/dynamicrange2




I can't wait to see the rest.

It seems to indicate that there might not be a lot of room for improvement
in top end CCDs.

Bob

Bob
Take a look at my other dynamic range page:
http://clarkvision.com/imagedetail/d...ignal.to.noise

and in particular, look at Figure 2. Figure 2 shows that the 1D Mark II
is working at the photon noise limit. The only way to improve on that is
to make larger pixels to collect more photons into a larger well
(which means less spatial resolution). The other improvement, which would
help low signals, is to lower the read noise and lower the dark current for
long exposures. But for everyday full light photography, the 1D Mark II
8-microns/pixel performance is the sweet spot that is essentially at
the theoretical best. If you make smaller pixels, and remain at the photon
noise limit, you collect less photons per pixel, so the noise goes up.
Larger chips is the other solution (lusting for the new 1Ds Mark II).
The other improvement would be to go to 14 bit A to D conversion. That would
help the low end get even better at low iso, but not the high end, where
photon statistics dominate.

Roger

bob wrote:

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


I've been running tests and have some interesting new plots
of film and digital dynamic range. This is the first of about
10 graphs on this page, but I though I would share it for comments
while I built the rest of the page. See:

http://clarkvision.com/imagedetail/dynamicrange2




I can't wait to see the rest.

It seems to indicate that there might not be a lot of room for improvement
in top end CCDs.

Bob

Bob
Take a look at my other dynamic range page:
http://clarkvision.com/imagedetail/d...ignal.to.noise

and in particular, look at Figure 2. Figure 2 shows that the 1D Mark II
is working at the photon noise limit. The only way to improve on that is
to make larger pixels to collect more photons into a larger well
(which means less spatial resolution). The other improvement, which would
help low signals, is to lower the read noise and lower the dark current for
long exposures. But for everyday full light photography, the 1D Mark II
8-microns/pixel performance is the sweet spot that is essentially at
the theoretical best. If you make smaller pixels, and remain at the photon
noise limit, you collect less photons per pixel, so the noise goes up.
Larger chips is the other solution (lusting for the new 1Ds Mark II).
The other improvement would be to go to 14 bit A to D conversion. That would
help the low end get even better at low iso, but not the high end, where
photon statistics dominate.

Roger

On Sun, 07 Nov 2004 20:15:45 -0700, "Roger N. Clark (change username
to rnclark)" wrote:

bob wrote:

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


I've been running tests and have some interesting new plots
of film and digital dynamic range. This is the first of about
10 graphs on this page, but I though I would share it for comments
while I built the rest of the page. See:

http://clarkvision.com/imagedetail/dynamicrange2




I can't wait to see the rest.

It seems to indicate that there might not be a lot of room for improvement
in top end CCDs.

Bob

Bob
Take a look at my other dynamic range page:
http://clarkvision.com/imagedetail/d...ignal.to.noise

and in particular, look at Figure 2. Figure 2 shows that the 1D Mark II
is working at the photon noise limit. The only way to improve on that is
to make larger pixels to collect more photons into a larger well
(which means less spatial resolution). The other improvement, which would
help low signals, is to lower the read noise and lower the dark current for
long exposures. But for everyday full light photography, the 1D Mark II
8-microns/pixel performance is the sweet spot that is essentially at
the theoretical best. If you make smaller pixels, and remain at the photon
noise limit, you collect less photons per pixel, so the noise goes up.
Larger chips is the other solution (lusting for the new 1Ds Mark II).
The other improvement would be to go to 14 bit A to D conversion. That would
help the low end get even better at low iso, but not the high end, where
photon statistics dominate.


Virtual all CCD cameras made today are photon noise limited over some
portion of their range. The readout noise is about 20 photo electrons
in modern cameras. If you say that photon noise dominates when it is
double the readout noise, the well depth will be 1600 photoelectrons.
Using the rule of thumb that you can collect between 800 and 1250
photoelectrons per square microns of silicon, sensor size would have
to drop down to around 2 square microns before photon noise ceased to
dominate

And a note in passing--the well depth on some individual sensors may
be much deeper than the rule of thumb predicts. Dispite a serious
effort on my part to find theoredical or experimental errors in the
numbers I get from my camera, (see some of my recent posts) I still
haven't been able to discover an error that would explain why my S/N
numbers points to a well depth 4 time greater than the rule of thumb
says it should be.

jpc

On Sun, 07 Nov 2004 20:15:45 -0700, "Roger N. Clark (change username
to rnclark)" wrote:

bob wrote:

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


I've been running tests and have some interesting new plots
of film and digital dynamic range. This is the first of about
10 graphs on this page, but I though I would share it for comments
while I built the rest of the page. See:

http://clarkvision.com/imagedetail/dynamicrange2




I can't wait to see the rest.

It seems to indicate that there might not be a lot of room for improvement
in top end CCDs.

Bob

Bob
Take a look at my other dynamic range page:
http://clarkvision.com/imagedetail/d...ignal.to.noise

and in particular, look at Figure 2. Figure 2 shows that the 1D Mark II
is working at the photon noise limit. The only way to improve on that is
to make larger pixels to collect more photons into a larger well
(which means less spatial resolution). The other improvement, which would
help low signals, is to lower the read noise and lower the dark current for
long exposures. But for everyday full light photography, the 1D Mark II
8-microns/pixel performance is the sweet spot that is essentially at
the theoretical best. If you make smaller pixels, and remain at the photon
noise limit, you collect less photons per pixel, so the noise goes up.
Larger chips is the other solution (lusting for the new 1Ds Mark II).
The other improvement would be to go to 14 bit A to D conversion. That would
help the low end get even better at low iso, but not the high end, where
photon statistics dominate.


Virtual all CCD cameras made today are photon noise limited over some
portion of their range. The readout noise is about 20 photo electrons
in modern cameras. If you say that photon noise dominates when it is
double the readout noise, the well depth will be 1600 photoelectrons.
Using the rule of thumb that you can collect between 800 and 1250
photoelectrons per square microns of silicon, sensor size would have
to drop down to around 2 square microns before photon noise ceased to
dominate

And a note in passing--the well depth on some individual sensors may
be much deeper than the rule of thumb predicts. Dispite a serious
effort on my part to find theoredical or experimental errors in the
numbers I get from my camera, (see some of my recent posts) I still
haven't been able to discover an error that would explain why my S/N
numbers points to a well depth 4 time greater than the rule of thumb
says it should be.

jpc

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

The other improvement would be to go to 14 bit A to D conversion. That would
help the low end get even better at low iso, but not the high end, where
photon statistics dominate.

Lacking some externality (14b flash converters suddenly become cheaper
than 12b, Dumbya passes a law making 12b converters illegal(*),
whatever) adding bits to the ADC won't make sense unless one can lower
the read-out noise by, hm, 2 bits ~ 12dB. That's so large that one
would think if it was possible it would have been done at this point.
Hm. Perhaps an option to read the image at different rates from the
sensors ("slow and smooth" or "fast and furious")? Maybe Canon will
start selling Peltier cooling accessories for their cameras, with
colour-matching hybrid titanium scraping tools made by magic elves so
the Professionals can chip the ice off their digital backs, and write
entire chapters on the related "process" and "workflow"?

(*) actually considered a few years ago; they did get a "broadcast
flag" though.

wrote in message
om...
"Roger N. Clark (change username to rnclark)"
wrote:
Lacking some externality (14b flash converters suddenly become cheaper
than 12b, Dumbya passes a law making 12b converters illegal(*),
....
(*) actually considered a few years ago; they did get a "broadcast
flag" though.

Eh? Tell us more!