How to measure ISO

In article ,
Sandman wrote:

Sandman:
The only one that has offered any kind of critical thinking is the
OP, Alfred. He did some math, confused some concepts, but the
math was valid,

No. You are the one who is confused. But it's a waste of time to
discuss things with you.

Since I provide support for my claims.

you only think you did.

what you provided does not support what you're saying.

you are very, very confused.

In article ,
Whisky-dave wrote:

Sandman:
..to achieve a specific brightness level. ISO 400 on a FF sensor
is four times less sensitive than ISO 400 on a MFT sensor. You
cannot use ISO values to compare sensor amplification if the
sensor differ in size.

Nothinng to do with it.

Incorrect, as I have shown.

you haven't shown anything other that you don't have a clue.

exactly.

In article ,
Sandman wrote:

Whisky-dave:
Som it doesnt; matter what sensor size or what file size you use
the sensitivity of it will be the same irrespecive of it
physical size.

Sandman:
Incorrect, because "ISO" doesn't tell you what signal
amplification a given sensor uses,

At least that is corect

Which is my entire point. Thank you.

the hell it is.

you've been babbling about iso being meaningless and noise levels and
all sorts of other stuff, confused by all of it.

In article ,
Whisky-dave wrote:

Soon yuo will be able to have a camera with NO moving parts,
not
even
the
shutter release will move.

where 'soon' was roughly a decade ago.

yes I have one 256X384 pixels I was refering to a more high end
camera
that people in this NG might consider buying.

the original iphone in 2007 had a 2 megapixel camera with no moving
parts, including the shutter release which was via a touch screen.

my first digital camera was long before then around April 2002
Digital cameras (without moving parts) existed before the iphone.

you originally said soon there will be a camera with no moving parts.

I was talking about a proper camera.

an iphone is a proper camera.

Not to most it's a phone with a camera.

it's a camera with no moving parts.

end of story.

it just happens to come with a phone attached to it.

Just happens, yeah sure.

yes.

and an iphone is also a music system that just happens to hae a phone
attached to it. It's also a TV just happens to hae a phone attached to it.
It's also a games machine just happens to hae a phone attached to it, it's
also a dicataphone just happens to hae a phone attached to it, it's alos a
mirror just happens to hae a phone attached to it. It's also a note book or
writing implement just happens to hae a phone attached to it. It's also can
be a library just happens to hae a phone attached to it.

yes, it does all sorts of things.

that doesn't change the fact that it's a camera with no moving parts.

i told you that was wrong, with the iphone being a good example. i also
said it might not have been the first, just the most widely known one.

the iphone is not the most widely know camera or the first digital camera.

it's the most widely known camera that doesn't have moving parts.

you'd have to prove that for me to believe it.

name one that preceded it that has no moving parts.

mention something else, such as an old minolta or sony camera, and
people would say they never heard of it.

So if you ask someone who makes the most famous or the best cameras you think
they will say Apple.

it's the most widely known example of a camera with no moving parts.

so far you have yet to mention another one.

now you say there was one 15 years ago. even better.

no nothing about it being better.

if you had a camera with no moving parts 15 years ago then yes it is
definitely better because you're even more wrong than i thought you
were.

As you have proved you've no idea.

much more than you ever will.

however, i bet it had moving parts, such as the shutter button and
focusing mechanism.

which camera was it?

a trust spy camera, it had an LCD but didn't display the picture but
usewd a
moving segment to indicate it was active.
yes it had a shutter buttom what camera doesn;t NO focusing NO aperature
no way of controliong exposure.

oh one of those. i remember those.

yep one of those, just noticed one of the first pictures I took with it
img10.bmp 19th april 2002 304kb, as I was transfering stuff from my work PC
to my newish work 27" iMac.

in other words, junk.

however, it had moving parts, at least the shutter button.

and you say the iphone isn't a proper camera??? hah.

No I don't consider an iphone a proper camera.

that's your problem.

meanwhile, the rest of the world does.

for me a proper camera is one where you can adjust the aperature, shutter
speed focus exposure, ISO and various other things that yuo can't do on teh
iphione or any camera phone.

in other words, most cameras.

instamatics, polaroid cameras and most compact film cameras, could not
adjust much of anything.

in your world, those weren't cameras. that's ****ed up.

But oif you think the iphone is one of teh best cameras on the market because
it can do 4k video then that's your choice not mine.

i didn't say it's the best on the market. i said it's the most well
known for a camera with no moving parts.

smartphones are good enough to where it can easily replace a more
traditional camera, which is why camera sales have tanked.

On 2015-11-18 17:33:56 +0000, nospam said:

In article ,
Sandman wrote:

nospam:
the problem is you're claiming that it also changes iso. it does
*not* change iso.

Sandman:
I have never claimed it changes ISO. Maybe you can't read?

yes you have. you keep saying that iso is meaningless and that
smaller sensors have a higher iso to compensate for the smaller
area.

Ok, so you can't read.

much better than you ever could and unlike you, i understand what it is
i read.

I have correctly stated that smaller sensors needs to amplify the signal more
to
provide an equally bright image as a larger sensor, while claiming the same
ISO,
meaning that ISO is not a measure of sensor sensitivity, but rather expected
brightness.

nope. you might *think* you're correct, but you are not.

what you stated is *wrong* and demonstrates a serious misunderstanding
of what is actually happening.

the brightness is the same regardless of sensor size. this is easily
demonstrated but you refuse to listen.

The problem is Jonas is talking about noise, and how it is introduced
due to sensor size differences and signal amplification to match light
sensitivity. ISO in the digital world is different to ASA/DIN/ISO for
film. However, as a guideline digital ISO is close enough to provide
equivalent sensitivity in all sensor sizes that making a full manual
digital camera exposure setting using the data from a handheld incident
light meter is going to give very close to equally exposed images from
a M4/3, an APS-C, or a FF regardless of MP density.

Noise is a completely different issue, and each of those sensors is
going to perform differently in that regard, in accord with the
particular sensor characteristics, and that is a result of pixel
density and CPU amplification.

A photographer shooting at a specific ISO on any size sensor is going
to be able to expose correctly according to that sensitivity, and
obtain images which appear equally exposed. One might well be noisier
than another, by that has nothing to do with exposure.


--
Regards,

Savageduck

In article 2015111810114199157-savageduck1@REMOVESPAMmecom,
Savageduck wrote:


I have correctly stated that smaller sensors needs to amplify the signal
more
to
provide an equally bright image as a larger sensor, while claiming the same
ISO,
meaning that ISO is not a measure of sensor sensitivity, but rather
expected
brightness.

nope. you might *think* you're correct, but you are not.

what you stated is *wrong* and demonstrates a serious misunderstanding
of what is actually happening.

the brightness is the same regardless of sensor size. this is easily
demonstrated but you refuse to listen.

The problem is Jonas is talking about noise, and how it is introduced
due to sensor size differences and signal amplification to match light
sensitivity.

he's talking about a lot of things, lumping them all together. that's
where he goes off the rails.

ISO in the digital world is different to ASA/DIN/ISO for
film.

no. iso 100 film will require the same exposure for a given scene as a
digital camera set to iso 100.

there is some variance because of how it can be measured but that's a
different issue.

However, as a guideline digital ISO is close enough to provide
equivalent sensitivity in all sensor sizes that making a full manual
digital camera exposure setting using the data from a handheld incident
light meter is going to give very close to equally exposed images from
a M4/3, an APS-C, or a FF regardless of MP density.

it'll be the same exposure, however, the results with digital will have
higher resolution, lower noise, wider dynamic range, etc.

Noise is a completely different issue, and each of those sensors is
going to perform differently in that regard, in accord with the
particular sensor characteristics, and that is a result of pixel
density and CPU amplification.

just as different films performed differently.

ektachrome, kodachrome, vevia and tri-x all looked different.

A photographer shooting at a specific ISO on any size sensor is going
to be able to expose correctly according to that sensitivity, and
obtain images which appear equally exposed. One might well be noisier
than another, by that has nothing to do with exposure.

yep.

as i said before, he's confusing equivalency, which matches noise, with
exposure/iso, which does not.

On Wed, 18 Nov 2015 03:54:27 -0800 (PST), Whisky-dave
wrote:

On Tuesday, 17 November 2015 18:06:07 UTC, peterN wrote:
On 11/17/2015 12:46 PM, nospam wrote:
In article 2015111621543686539-savageduck1@REMOVESPAMmecom,
Savageduck wrote:

How is it being exploited, when they don't know what monkey it is or how
it
is being exploited. To be exploited you must lose out in some way.

a monkey (it doesn't matter which one) is being used so that someone
else can profit without it having consented.

Neither monkeys nor words should be mistreated. To exploit someone,
you must deprive them of some benefit that they would otherwise enjoy.
You cannot exploit a monkey in this photograph issue because the
monkey is not being deprived of any benefit that would otherwise
accrue to the monkey.

http://dictionary.reference.com/browse/exploiting
2 to use selfishly for one's own ends:
/employers who exploit their workers./

which is *exactly* what peta is doing.

if the monkey could talk, it would tell peta to **** off.

PETA couldn't even find the specific monkey to sign a consent to act if
it wanted to, and if they did find said mokey, what were they going to
do? Get Koko the gorilla to act as Court interpretor?

they claim to be representing the monkey.

Does PETA have a signed authorization from the monkey?

Does it need one.
If someone is murdered the police don;t need authorization
from the corpse in order to investige and cgareg someone with murder.

They don't need another one. They already have one from the law which
imposes the *duty* on the police to investigate such matters.


it's nothing more than a publicity stunt.



--
PeterN
--

Regards,

Eric Stevens

On 2015-11-18 18:47:44 +0000, nospam said:

In article 2015111810114199157-savageduck1@REMOVESPAMmecom,
Savageduck wrote:


I have correctly stated that smaller sensors needs to amplify the signal
more
to
provide an equally bright image as a larger sensor, while claiming the same
ISO,
meaning that ISO is not a measure of sensor sensitivity, but rather
expected
brightness.

nope. you might *think* you're correct, but you are not.

what you stated is *wrong* and demonstrates a serious misunderstanding
of what is actually happening.

the brightness is the same regardless of sensor size. this is easily
demonstrated but you refuse to listen.

The problem is Jonas is talking about noise, and how it is introduced
due to sensor size differences and signal amplification to match light
sensitivity.

he's talking about a lot of things, lumping them all together. that's
where he goes off the rails.

ISO in the digital world is different to ASA/DIN/ISO for
film.

no. iso 100 film will require the same exposure for a given scene as a
digital camera set to iso 100.

Correct. I should have said they were different in the way they are
implemented in film where it is fixed (other than doing stuff like
pushing Tri-X to 1200 ASA) to a particular film type, or digital where
it is variable in the camera.

there is some variance because of how it can be measured but that's a
different issue.

Yup!

However, as a guideline digital ISO is close enough to provide
equivalent sensitivity in all sensor sizes that making a full manual
digital camera exposure setting using the data from a handheld incident
light meter is going to give very close to equally exposed images from
a M4/3, an APS-C, or a FF regardless of MP density.

it'll be the same exposure, however, the results with digital will have
higher resolution, lower noise, wider dynamic range, etc.

Let's just stick to exposure, as those other issues can also apply to
different sensor characteristics.

Noise is a completely different issue, and each of those sensors is
going to perform differently in that regard, in accord with the
particular sensor characteristics, and that is a result of pixel
density and CPU amplification.

just as different films performed differently.

ektachrome, kodachrome, vevia and tri-x all looked different.

A photographer shooting at a specific ISO on any size sensor is going
to be able to expose correctly according to that sensitivity, and
obtain images which appear equally exposed. One might well be noisier
than another, by that has nothing to do with exposure.

yep.

as i said before, he's confusing equivalency, which matches noise, with
exposure/iso, which does not.

Not everybody in this thread is on the same page.


--
Regards,

Savageduck

On 18 Nov 2015 08:01:18 GMT, Sandman wrote:

In article , Eric Stevens wrote:

Sandman:
It's also important here to note that light isn't projected as a
"cone" in a camera. This misconception comes from images like
these:

https://c2.staticflickr.com/6/5442/17491457679_4003be7f39_o.png

Which just describes how light is focused by the lens. If you
looked at that, you might be led to think that the image you are
taking is being focused in a small point in the center of the
focal plane. Or that you're using a magnifier to burn some ants.

Fact is, all light comes in from different angles, and is
projected over the entire sensor, not just the middle.

But it is projected in cones, from different directions.

Not really. A photon always travels in a straight line (well, almost always) and
the lens in the camera changes its direction. Or rather, the *lenses* in the
camera changes its direction many times.

The only cone shape you could talk about is the inverse one:

http://jonaseklundh.se/files/lens_cone.png

That's field of view. Previously you were describing the paths of ray
bundles. http://www.edmundoptics.com/images/a.../fig-9a-rs.gif
shows bundles of rays coming from different parts of the object and
constructing the image by being focussed on different parts of the
sensor. The fact that it's a multi-element sensor doesn't change what
happens.

Where the larger "cone" is the angle of view of the lens, and the smaller one on
the other side of the lens is the image focused.
--

Regards,

Eric Stevens

In article 2015111810592963084-savageduck1@REMOVESPAMmecom,
Savageduck wrote:


ISO in the digital world is different to ASA/DIN/ISO for
film.

no. iso 100 film will require the same exposure for a given scene as a
digital camera set to iso 100.

Correct. I should have said they were different in the way they are
implemented in film where it is fixed (other than doing stuff like
pushing Tri-X to 1200 ASA) to a particular film type, or digital where
it is variable in the camera.

push processing is the film equivalent of amplifying the sensor data.

there is some variance because of how it can be measured but that's a
different issue.

Yup!

However, as a guideline digital ISO is close enough to provide
equivalent sensitivity in all sensor sizes that making a full manual
digital camera exposure setting using the data from a handheld incident
light meter is going to give very close to equally exposed images from
a M4/3, an APS-C, or a FF regardless of MP density.

it'll be the same exposure, however, the results with digital will have
higher resolution, lower noise, wider dynamic range, etc.

Let's just stick to exposure, as those other issues can also apply to
different sensor characteristics.

yep.

Noise is a completely different issue, and each of those sensors is
going to perform differently in that regard, in accord with the
particular sensor characteristics, and that is a result of pixel
density and CPU amplification.

just as different films performed differently.

ektachrome, kodachrome, vevia and tri-x all looked different.

A photographer shooting at a specific ISO on any size sensor is going
to be able to expose correctly according to that sensitivity, and
obtain images which appear equally exposed. One might well be noisier
than another, by that has nothing to do with exposure.

yep.

as i said before, he's confusing equivalency, which matches noise, with
exposure/iso, which does not.

Not everybody in this thread is on the same page.

actually most people are on the same page.

only one is not.