Re: Dinosaurs

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

I am not saying there is anything wrong with your reasoning, but when
the demonstrated facts don't match your conclusions then it is time to
check your assumptions.

They are not assumptions. It is hard data on sensor performance.
Try reading.


Not hard data at all -- yet another list of unproven theories with
almost no supporting data. Those articles fail to explain how
manufacturers keep coming out with lower noise cameras having more
pixels on the same size sensors. Like you, they deny the facts because
those facts don't fit their theories.

If you read and check references at the end of the article, you
would find many other studies that point to the same conclusion.
The data are clear and tell the correct story. You and Stacey,
on the other hand sound like those film fanatics in the film versus
digital wars. You wave your arms and say it isn't so and this
or that proves me wrong. Well, show a real study that shows
real data that proves your point. Why don't you take data
from dpreview.com and plot it up and see if you can actually
prove your point?

Neither do those articles show how those theories apply to real-world
photography. It is great to talk about photon rain and draw a graph,
but the graphs make the same mistakes I pointed out earlier: they
assume that sensors will not become more efficient and they assume that
a smaller sensor size means a smaller pixel size. Neither of those
assumptions are valid. In fact, the author of "Does Pixel Size Matter"
seems to be confused. Nowhere does he tell us pixel size; he only talks
about pixel spacing and then uses pixel size and pixel spacing
interchangeably, which they are not.

The manufacturers use microlenses over the pixels to make effectively
100% fill factors. Then effectively pixel pitch = pixel size.
With CMOS, actual active area of a pixel may be only 25%, so with
microlenese, actual pixel size is irrelevant.

You can talk about quantum efficiency all you want. Those articles
throw the term around a lot. I suspect that the author of those
articles has about as clear an understanding of quantum physics as the
Ramtha group. Great for making New Age movies. Poor for understanding
physics.

All you have to do is follow the references and you will see many
other studies that come to the same conclusions. E.g. see:

http://www.astrosurf.org/buil/20d/20dvs10d.htm

http://spiff.rit.edu/classes/phys559/lectures/gain/gain.html

http://www.britastro.org/vss/ccdtable.html

http://www.kodak.com/global/plugins/acrobat/en/digital/ccd/papersArticles/PhotographyWithAn11-megapixel35mmFormatCCD.pdf

See figure 1 for quantum efficiencies of sensors:
http://huhepl.harvard.edu/~LSST/general/Janesick_paper_2003.pdf

Then a simple google search will show you more sites and manufacturer's
data sheets.

You claim that you are an image tester, yet it has been shown over and
over that you have not got the faintest idea of how your theories apply
to real photographs. Great, if all you want to shoot are test patterns
and the inside of lens caps. Poor, if you want to take pictures in a
rain forest. If you are really an image tester, you know that digital
noise has been reduced despite increasing the number of pixels. Yet you
ignore that to promote a pet theory without any hard data that supports
it.

Just what I expected: attack personal integrity if you don't like
the data. Here is my bio: http://www.clarkvision.com/rnc
and my publications:
http://www.clarkvision.com/rnc/publist.html
Many of the publications evaluate sensors, including NASA spacecraft.

So what are your qualifications to evaluate quantum effects?

I apply the technical knowledge of sensors to produce better
photographs. My photos are at: http://www.clarkvision.com
and include international contest winners. I currently have
photos hanging in galleries.

Do you? Where are your photos?


A little honesty would be greatly appreciated here. If you really have
data that shows the quantum limit has been reached, lets see it.

All of the above links were referenced from my pages, and prove
the point.

How about a reference that shows real data that supports
your contention?

I think what you and Stacey are seeing is that manufactures have
improved their electronics over the last 5 or so years to get
their cameras up to the photon limits the CCDs and CMOS sensors
had all along. They added microlenses to make the fill factors
100%. The sensors were always capable of producing at the
photon noise limit, and have been so for years before consumer
digital cameras came out.

You also seem to ignore the fact that I said that quantum efficiencies
of the sensors in consumer cameras could be improved by 3 to 5x,
so there is room for improvement.

Roger
.