digital camera as exposure meter

On Aug 14, 9:38 pm, Richard Polhill
wrote:


I was going to suggest one of these:http://preview.tinyurl.com/325sgw

but I suspect Floyd thinks a dSLR would be much better for the job.

dang, thats just what I needed for this one:
http://members.iinet.net.au/~nsouto/photos/pumpiron.jpg

;-)

In article ,
(Floyd L. Davidson) wrote:

Noons wrote:

You have to go to 1949 for the birth of Information
Theory.

Bull**** of the highest degree. You have to go much
EARLIER than that.

Your ignorance is absolutely astounding.

This is one example, I snipped the rest, which were all
at the same level.

Harry Nyquist: 1924, "Certain Factors Affecting Telegraph Speed"

Ralph Hartley: 1928, "Transmission of Information"

Alan Turing: 1940, used similar ideas as part of the statistical
analysis of the breaking of the German second world war Enigma ciphers

Claude E. Shannon: 1944, Introduced the qualitative and quantitative
model of communication as a statistical process underlying information
theory.

And, finally:
Claude E. Shannon: 1948, "A Mathematical Theory of Communication"


See how easy it all is? Still beats the hell outta me what any of this
has to do with photography, or using a camera as a light meter -- which
is stupid unless your light meter is busted, outta batteries, or still
in the hotel. Ever tried it? It is a complete PITA since the camera's
meter takes into account all the optical "qualities" of the lens it is
reading through ... the lens you will manifestly _not_ be using on your
medium format camera. There is also the "ISO Bias" -- Japanese
cameras/lenses/meters are calibrated differently than German
cameras/lenses/meters. I would _never_ use anything but a Gossen meter
for my Hasselblads, and built-in Leica or handheld Gossen meters for my
Leicas.

Besides, you can't stick it in your back pocket when yer not using it.

On Aug 15, 11:14 am, Niccolo Machiavelli
wrote:



Besides, you can't stick it in your back pocket when yer not using it.

have you ever tried to stick a Gossen lunasix F in your back pocket?

;-)

In article . com,
Noons wrote:

On Aug 15, 11:14 am, Niccolo Machiavelli
wrote:



Besides, you can't stick it in your back pocket when yer not using it.

have you ever tried to stick a Gossen lunasix F in your back pocket?

;-)

Nope but a Luna Star and a Digisix fit just fine. Better than a DSLR.

--Nicco

Niccolo Machiavelli wrote:
In article ,
(Floyd L. Davidson) wrote:

Noons wrote:

You have to go to 1949 for the birth of Information
Theory.

Bull**** of the highest degree. You have to go much
EARLIER than that.

Your ignorance is absolutely astounding.

This is one example, I snipped the rest, which were all
at the same level.

Harry Nyquist: 1924, "Certain Factors Affecting Telegraph Speed"

Ralph Hartley: 1928, "Transmission of Information"

Alan Turing: 1940, used similar ideas as part of the statistical
analysis of the breaking of the German second world war Enigma ciphers

None of them *ever* used the term "Information Theory".

Claude E. Shannon: 1944, Introduced the qualitative and quantitative
model of communication as a statistical process underlying information
theory.

Close, but that isn't it either!

And, finally:
Claude E. Shannon: 1948, "A Mathematical Theory of Communication"

Bingo. Now everyone can study "Information Theory".

See how easy it all is?

So you don't know the difference between researching
telegraph speed or transmission systems and developing
*Information Theory*.

A simple google search '"information theory" shannon'
would have explained an awful lot, if only you had
tried.

Even wikipedia gets it right! You probably should start
with this URL.

http://en.wikipedia.org/wiki/Information_theory

But note that wikipedia is not known for absolute
accuracy, and I've not read this entire article and cannot
vouch for anything other than one statement it makes:

Information theory is generally considered to have
been founded in 1948 by Claude Shannon in his seminal
work, "A Mathematical Theory of Communication."

As you can easily verify from any number of other sources,
that is an accurate assessment.

http://www.bell-labs.com/news/2001/february/26/1.html
http://ieeexplore.ieee.org/xpl/freea...number=1578661
http://www.lecb.ncifcrf.gov/~toms/shannontribute.html
http://www-groups.dcs.st-and.ac.uk/~...s/Shannon.html
http://www.nyu.edu/pages/linguistics...0003/shan.html

The term "Information Theory" didn't exist until Shannon published
his work.

Still beats the hell outta me what any of this
has to do with photography,

Actually it is pretty simple: photographs contain information.

Anything you do to manipulate that information (e.g.,
develop film, measure light values, quantize sensor
data etc.) is subject to "Information Theory". For
example it makes no difference if you do an Unsharp Mask
with wet processing in a darkroom or digitally using
software, the theory of what happens and why is
precisely the same.

or using a camera as a light meter -- which
is stupid unless your light meter is busted, outta batteries, or still
in the hotel. Ever tried it?

Actually I've been using a camera as a light meter since
I first bought a Pentax Spotmatic back in the middle
60's.

Separate light meters haven't been all that popular for
nearly half a century now...

It is a complete PITA since the camera's
meter takes into account all the optical "qualities" of the lens it is
reading through ... the lens you will manifestly _not_ be using on your
medium format camera.

Oh my goodness, you will be using the lense from your
light meter on that MF camera????

There is also the "ISO Bias" -- Japanese
cameras/lenses/meters are calibrated differently than German
cameras/lenses/meters.

And of course you aren't able to deal with that
difference, I suppose? There is just about the same
amount of difference between some lenses when set to the
same f/stop, but you probably don't have much difficulty
with that, eh?

I would _never_ use anything but a Gossen meter
for my Hasselblads, and built-in Leica or handheld Gossen meters for my
Leicas.

That's wonderful. But if you think that is logical,
it ain't.

Besides, you can't stick it in your back pocket when yer not using it.

Same could be said of many things, including your
cameras; but then the irrational bit doesn't seem to
bother you.

--
Floyd L. Davidson http://www.apaflo.com/floyd_davidson
Ukpeagvik (Barrow, Alaska)

(Floyd L. Davidson) wrote:

Separate light meters haven't been all that popular for
nearly half a century now...

Q: What do you call a DSLR when it is used as a light meter for a medium
format camera?

A: A Separate Light Meter.

See how that works?

Lobby Dosser wrote:
(Floyd L. Davidson) wrote:

Separate light meters haven't been all that popular for
nearly half a century now...

Q: What do you call a DSLR when it is used as a light meter for a medium
format camera?

A: A Separate Light Meter.

See how that works?

What works, trimming enough context that a single
phrase, out of context, appears to mean something it
doesn't when in context?

Out of an article with 130 lines of text, the only
thing you can even attempt to dispute is two lines,
a fragment of a sentence, that was never meant to
say what you dispute...

Looks like you don't have much of a leg to stand on
there, once someone does show you how that works.
What I notice though is that by yourself you never
do seem to "get" these things to begin with...

--
Floyd L. Davidson http://www.apaflo.com/floyd_davidson
Ukpeagvik (Barrow, Alaska)

Lobby Dosser wrote:
(Floyd L. Davidson) wrote:

Separate light meters haven't been all that popular for
nearly half a century now...

Q: What do you call a DSLR when it is used as a light meter for a medium
format camera?

A: A Separate Light Meter.

See how that works?

We've wasted too much time with this prat already.

On Aug 15, 8:59 pm, Richard Polhill
wrote:
Lobby Dosser wrote:
(Floyd L. Davidson) wrote:

Separate light meters haven't been all that popular for
nearly half a century now...

Q: What do you call a DSLR when it is used as a light meter for a medium
format camera?

A: A Separate Light Meter.

See how that works?

We've wasted too much time with this prat already.

Amen

In article ,
(Floyd L. Davidson) wrote:


Harry Nyquist: 1924, "Certain Factors Affecting Telegraph Speed"

Ralph Hartley: 1928, "Transmission of Information"

Alan Turing: 1940, used similar ideas as part of the statistical
analysis of the breaking of the German second world war Enigma ciphers

None of them *ever* used the term "Information Theory".

"The map is not the territory."

The term is not the field.

If you weren't the one who took the eagle photos, I haven't seen any
good photos of the Arctic from you, compared to these:

http://luminous-landscape.com/forum/...18236&hl=whale

And those were taken with a medium format film camera, not that digital
medium format cameras couldn't have done something equally as good, but
what makes a photograph memorable goes well beyond "information theory"
or the engineering used to make the camera. Getting the exposure and
focus as you want it requires thinking about the final effect, not just
putting the maximum pixels on the recording media, whatever that is.
And some of what makes art work for humans hasn't changed since the
Paleolithic when people used wax and mineral pigments to lay information
down.

Whoever took the photos of the eagles eating the young seal is a decent
photographer.