How to measure ISO

In article ,
Sandman wrote:

Sandman:
FACT: Smaller sensors have smaller photo sites.

nospam:
no.

the photosites *might* be smaller, but it's not always the case.
they might be the same size or even larger.

*if* the megapixel count is the same on both sensors, *then* the
photosites will be smaller on the smaller sensor. if it's
different the you have more variables in the mix.

Sandman:
This has already been supported by me:

http://jonaseklundh.se/files/cameras_since_2013.png

Posting a list you have pinched from somewhere else without
explanation doesn't offer support for anything.

I made that list, from data from dpreview. Do you have a better list? No?
Then
it is valid.

it doesn't work that way.

Those are the MFT and FF cameras released since April 2013 as listed by
dpreview. Do you disagree with the list?

who cares. it's nothing more than a list of cameras made in the past
few years. big deal. that says *nothing* about photosite sizes. nothing
at all.

Fine, produce another list that
counters it, or accept it as valid.

if you insist:
olympus e-1 and nikon d800.
nikon d70 and nikon d800.
canon 1d and sony alpha 7r ii.

This is how proof works. One has a claim, one posts supporting data, which
remains valid until it has been invalidated. Merely claiming it isn't valid
is
just nospam-like hot air.

claiming that a list of recent cameras is somehow proof of something is
beyond ludicrous. it's truly ****ed up.

put simply: you're full of ****.

Sandman:
FACT: Smaller photo sites capture less light

nospam:
true, but that's independent of sensor size.

Sandman:
Incorrect, given the fact that all contemporary cameras have
smaller photo sites if they have smaller sensors.

Are you trying to say that a contemporary camera which has smaller
photosites has a smaller sensor?

No, all contemporary cameras with smaller sensors have smaller photosites.
This
was obvious from my sentence above.

facts do not care what's contemporary and what's not. facts do not care
what is in stock at b&h.

the fact is that there *are* smaller sensors with larger photosites.

in other words, you're wrong.

Sandman:
FACT: For a smaller sensor with smaller photo sites
to achieve the same brightness as a larger sensor with larger
photo sites, the signal needs to be amplified

nospam:
no.

Sandman:
Note: no support for opposing view. Fact remains factual.

But it's not a fact.

It is. I have given support.

it isn't and you haven't.

If you want to disprove it, you have to post
support that proves my support wrong.

already done, multiple times and by multiple people.

you want no part of it. all you do is say 'incorrect' and keep on
babbling.

Fact remains factual.

too bad you don't have any to offer.

Sandman:
In order to do this, the troll often snips out the context in
which a statement was made, and attack the statement on its own,
isolated from the context, like you did in this part of the
thread, reference he



Those statements stand on their own.

But have to be taken out of their context to be attacked semantically by a
troll.

Sandman:
I have, correctly, used the terms as used by people. This very
thread has the subject "How to measure ISO". ISO is amplification
of signal (unless it's the base ISO), and this is what people
refer to as sensor sensitivity. Very much like you did he

Back to the beginning. You haven't learned or (more likely)
understood a thing.

Such as? Don't be afraid to be specific.

What is more you use words in a very loose fashion entirely
unsuitable for the discussion of a technical subject.

This wasn't a technical subject from the start. It gradually became more and
more technical when nospam couldn't wrap his head around the facts. Then you
joined and you did get it, your math corroborated my math and it would have
been just nice if you hadn't gone south when you realized you agreed with me.

Sandman:
"See https://photographylife.com/what-is-iso-in-photography "In
very basic terms, ISO is the level of sensitivity of your camera
to available light."" / Eric Stevens- 11/11/2015

True.

"Amplification is NOT sensor sensitivity."
/ Eric Stevens- 11/21/2015

Sandman:
"ISO is only concerned with sensitivity." / Eric Stevens-
11/14/2015

True

"Amplification is NOT sensor sensitivity."
/ Eric Stevens- 11/21/2015

Sandman:
With a given exposure, a MFT sensors receives
(roughly) one fourth the amount of light as a FF sensor. If
you were to give the MFT sensor the same amount of total
light (I trust you are familiar with how to operate a camera
to give a sensor more light), the signal amplification will
be comparable.

False. Completely false.

So prove it wrong - merely blowing hot air in my general direction says exactly
nothing.

I have proven it correct, using math and example footage. You have been 100%
unable to disprove any substantiation I have supplied, so they remain valid to
this day, regardless of the amount of whining you do.

Eric Stevens:
That's all very fine, but what are the units of measure to
enable you to define whether or not the same amount of light has
been received?

Sandman:
The actual amount is irrelevant. The fact that one receives 25% of
the other is what is relevant. We're discussing a comparison, not
how to measure amount of light.

You still haven't understood, have you? Are you talking about the
level of illumination (e.g. Lux) or are you talking about the total
exposure (e.g. Lux x Seconds)?

Both. Pick one.

Sandman:
Simple physics.

Which requires the precise use of language to describe.

Only for a troll that would rather argue semantics than admit to being wrong.

--
Sandman

In article , Eric Stevens wrote:

Sandman:
FACT: Smaller sensors have smaller photo sites.

nospam:
no.

the photosites *might* be smaller, but it's not always the
case. they might be the same size or even larger.

*if* the megapixel count is the same on both sensors, *then*
the photosites will be smaller on the smaller sensor. if
it's different the you have more variables in the mix.

Sandman:
This has already been supported by me:

http://jonaseklundh.se/files/cameras_since_2013.png

Eric Stevens:
Posting a list you have pinched from somewhere else without
explanation doesn't offer support for anything.

Sandman:
I made that list, from data from dpreview. Do you have a better
list? No? Then it is valid.

Those are the MFT and FF cameras released since April 2013 as
listed by dpreview. Do you disagree with the list? Fine, produce
another list that counters it, or accept it as valid.

This is how proof works. One has a claim, one posts supporting
data, which remains valid until it has been invalidated. Merely
claiming it isn't valid is just nospam-like hot air.

Proof of what exactly?

The fact listed above, still quoted.

You haven't either told us or demonstrated
exactly what conclusions you have drawn from that data.

I have, several times.



--
Sandman

Sandman:
FACT: Brightness is the result of captured light

Whisky-dave:
No it is not. Brightness is the intensisty of
seen over a period of time.

Sandman:
I.e. the amount of light.

Whisky-dave:
The number of photons received per unit time.

Sandman:
I.e. the amount of light.

NO NO NO NO!

"photons received per unit time" is the rate at which light arrives.

Correct, and since the examples have been about the same exposure for both
sensors, it relates to an amount of light.

'Photons received' is a quantity of light.

Which is a result of amount of photons received during a given unit of time. It
could be 1/250 or 1/60, it doesn't matter. Go back 12 days to see the examples
that I've posted many times since then as well.

The two are very different and you, with your contempt for what you
call 'semantics', seem to use the two concepts interchangeably as it
suits you.

I don't.

--
Sandman

In article , Eric Stevens wrote:

Sandman:
As I said - a lot of people care about noise, which
is what amplification leads to. Not sure what the babble
above is supposed to say in this context.

Eric Stevens:
And there is the problem: you don't know what the terms mean.

Sandman:
What term?

Most of the terms you have just snipped. Another of your less
pleasant debating tricks.

So you don't know, huh?

nospam:
not quite, because the same amount of light on
smaller photosites would likely saturate them.

Sandman:
Incorrect.

Eric Stevens:
He is correct. If you think we are wrong, please explain.

Sandman:
There is no "likely" since there is no amount of light given. His
"likely" is a red herring that doesn't relate to my factual
statement.

... your factually incorrect statement. --

...that has yet to be proven false by any troll in this thread. Go figure.

--
Sandman

In article ,
Sandman wrote:

Sandman:
With a given exposure, a MFT sensors receives
(roughly) one fourth the amount of light as a FF sensor. If
you were to give the MFT sensor the same amount of total
light (I trust you are familiar with how to operate a camera
to give a sensor more light), the signal amplification will
be comparable.

False. Completely false.

So prove it wrong - merely blowing hot air in my general direction says
exactly
nothing.

if anyone is spewing hot air, it would be you.

it's been shown to be wrong multiple times by multiple people.

I have proven it correct, using math and example footage. You have been 100%
unable to disprove any substantiation I have supplied, so they remain valid
to
this day, regardless of the amount of whining you do.

you haven't proven anything.

you're confused by several concepts and have fabricated your own proof.

cite a peer-reviewed source that supports your claims or stfu.

Eric Stevens:
That's all very fine, but what are the units of measure to
enable you to define whether or not the same amount of light has
been received?

Sandman:
The actual amount is irrelevant. The fact that one receives 25% of
the other is what is relevant. We're discussing a comparison, not
how to measure amount of light.

You still haven't understood, have you? Are you talking about the
level of illumination (e.g. Lux) or are you talking about the total
exposure (e.g. Lux x Seconds)?

Both. Pick one.

more evidence that you're confused.

Sandman:
Simple physics.

Which requires the precise use of language to describe.

Only for a troll that would rather argue semantics than admit to being wrong.

that makes you a troll.

at least we cleared that up.

In article ,
Sandman wrote:


Sandman:
As I said - a lot of people care about noise, which
is what amplification leads to. Not sure what the babble
above is supposed to say in this context.

Eric Stevens:
And there is the problem: you don't know what the terms mean.

Sandman:
What term?

Most of the terms you have just snipped. Another of your less
pleasant debating tricks.

So you don't know, huh?

he knows. you're just playing debating games.

nospam:
not quite, because the same amount of light on
smaller photosites would likely saturate them.

Sandman:
Incorrect.

Eric Stevens:
He is correct. If you think we are wrong, please explain.

Sandman:
There is no "likely" since there is no amount of light given. His
"likely" is a red herring that doesn't relate to my factual
statement.

... your factually incorrect statement. --

..that has yet to be proven false by any troll in this thread. Go figure.

much of what you said has been proven false and by several different
people on several different occasions.

what i wrote above is 100% true.

prove it wrong or stfu.

In article , nospam wrote:

Sandman:
With smaller photo sites, found in smaller sensors,
each photo site receives less light and the signal needs to
be amplified more while reporting the same ISO value as a
larger sensor.

nospam:
smaller sensors *might* have smaller photosites.

Sandman:
Smaller sensors have smaller photo sites:

http://jonaseklundh.se/files/cameras_since_2013.png

except when they don't.

olympus e-1 and nikon d800.

2003 vs. 2012.

nikon d70 and nikon d800

2004 vs. 2012

canon 1d and sony 7r ii.

2001 vs. 2015

You really had to dig through the ages to find smaller sensor cameras with
bigger photo sites. As you can see, I talk about contemporary cameras, and
comparing them. Few people would compare a Nikon D70 with a D800. But het,
semantics, right?

Sandman:
More amplification leads to more noise, which is what
makes people think smaller sensors are noisier, when in
reality they aren't, they're just not receiving as much
light.

nospam:
you just said a smaller sensor needs more amplification,
resulting in more noise, which means smaller sensors are
noisier.

Sandman:
Indeed - since they are getting less light.

which means it's not due to amplification.

It means exactly that, since for them to produce an equally bright image at the
same ISO value, the signal needs to be amplified more. If you give them the
same amount of total light, the signal need not be amplified more than on the
larger sensors, and you get an equally clean image.

Which, incidentally, is exactly what I've been saying for the last 12 days, and
something you still can't wrap your head around.

nospam:
now you say they really aren't.

Sandman:
If they get the same amount of light.

which affects exposure.

Well, duh.

nospam:
make up your mind.

Sandman:
Learn to read.

take your own advice.

No need, I read just fine, thanks.

Sandman:
If you give them the same amount of total light (i.e.
the same amount of light per photo site), the noise levels
are comparable to that of a larger sensor, while brightness
is the same. But, you have to adjust the ISO value down by the
crop factor squared (roughly).

nospam:
not quite, because the same amount of light on smaller
photosites would likely saturate them.

Sandman:
Incorrect.

nope.

it's *exactly* correct.

Incorrect, since your "likely" assumes a given amount of light, an amount that
was not given or specifically stated. The same amount of light CAN saturate a
given photo site, but it's not "likely", since it's all up to the exposure.

a smaller photosite has a lower full well capacity which means it
will saturate with less light than a larger photosite.

simple physics.

Indeed - using supposed input data that was never specified, making the
"likely" another empty claim.

think rain buckets. a smaller bucket holds less water than a larger
bucket.

Indeed, and that's the example that I used 12 days ago, and it flew past you
then as well.

We're talking about a given exposure, for example:

Contemporary FF sensor: 1/250, f.28 with an ISO of 800

Right, no problem there. This will produce a given amount of light. Let's
assume it produces an even exposure over the sensor, a perfectly composed image
that looks nice. Very well.

Now do the exact same exposure on a contemporary MFT sensor.

This will of course expose the same amount of light per unit area, but we have
less unit areas, so not all light is being used. Furthermore, the photo sites
are smaller, so each one gets slightly less signal.

This means that when set to ISO 800, the MFT sensor with its smaller photo
sites will have to amplify its signal *more* to achieve the same level of
brightness that the larger sensors does.

This leads to noise, so the MFT sensor will be noisier.

So you adjust the ISO to the crop factor squared, set it to ISO 200. And then
you adjust your exposure to 1/60, which is four times longer than 1/250.

Suddenly, you have given the MFT sensor the same amount of light as the larger
sensor, and you are thus amplifying the signal comparably. This means that your
exposure will be next to identical to the larger sensor.

This, of course, tells us that the "ISO" value is merely a way to achieve a
certain level of brightness, not that the level of amplification is comparable
between the sensors.

I.e., what I've been saying all along. Nothing has changed.

--
Sandman

In article , nospam wrote:

Sandman:
So prove it wrong - merely blowing hot air in my general direction
says exactly nothing.

if anyone is spewing hot air, it would be you.

it's been shown to be wrong multiple times by multiple people.

Message-ID? No? Didn't think so.

Sandman:
I have proven it correct, using math and example footage. You have
been 100% unable to disprove any substantiation I have supplied,
so they remain valid to this day, regardless of the amount of
whining you do.

you haven't proven anything.

Incorrect. The word "proof" doesn't inherently mean that something is factual in
itself. It is something that supports a position. I have provided many pieces of
evidence that support my position. You have provided exactly none.

cite a peer-reviewed source that supports your claims or stfu.

Like you did? Hahahahahahaha!!!

snip trolling

--
Sandman

In article , nospam wrote:

Sandman:
As I said - a lot of people care about noise,
which is what amplification leads to. Not sure what the
babble above is supposed to say in this context.

Eric Stevens:
And there is the problem: you don't know what
the terms mean.

Sandman:
What term?

Eric Stevens:
Most of the terms you have just snipped. Another of your less
pleasant debating tricks.

Sandman:
So you don't know, huh?

he knows. you're just playing debating games.

Here comes nospam with his hot air

nospam:
not quite, because the same amount of light on
smaller photosites would likely saturate them.

Sandman:
Incorrect.

Eric Stevens:
He is correct. If you think we are wrong,
please explain.

Sandman:
There is no "likely" since there is no amount of
light given. His "likely" is a red herring that doesn't
relate to my factual statement.

Eric Stevens:
... your factually incorrect statement. --

Sandman:
..that has yet to be proven false by any troll in this thread. Go
figure.

much of what you said has been proven false and by several different
people on several different occasions.

But can in no way be provided by you More hot air.

--
Sandman