Finally got to the point where no new camera holds my interest(waiting for specific offering)

In article , Eric Stevens
wrote:

But the digital DR of the output of the ADC is not the same as the
analog DR of the sensor. Nor is there any reason why it should be.

Well that's exactly what I said. If they are publishing the DR of the
sensor, why would any photographer care about that, if the DR is then
limited by the ADC? The usable output of any camera we buy is all we
care about.

There is no reason why the DR of the sensor should not be compressed
to make it fit within the limits of the ADC.

actually there are several reasons, but the only one that matters is
that the sensor data *isn't* compressed or altered in any way prior to
the adc.

It is inherent in the operation of an ADC that the full DR of the
sensor is incorporated in the bit band-width of the output.

what's inherent is that the adc is the limiting factor, unless the
sensor is crap, which is not the case in a d800.

arguing about a non-existent camera, one which is likely to never exist
at all, is pointless and actually, rather bizarre.

I thought we were arguing about what DxO have done when measuring the
DR of the various Nikon cameras you have cited.

yes, so why bring up a non-existent camera?

In article , Eric Stevens
wrote:

dxo is reporting the dynamic range of various *cameras*.

and even if you ignore the 14 bit issue, their numbers are highly
suspect.

the nikon d800 and d800 are identical cameras, the only difference
being the lack of an anti-alias filter on the d800e, something which
does not affect dynamic range (only aliasing). thus, the results should
be *the* *same* (other than alias artifacts on high frequency content).

Light passes through the filter which affects the spectrum detected by
the sensor. Of course this will affect the dynamic range.

nonsense. an aa filter has *zero* effect on dynamic range.

You know that do you?

yes.

Show me the data.

show me the data that it does.

Google shows that a hell of a lot of work has been done on the
spectral properties of anti-aliasing filters. You should write to all
the authors and tell them they are wasting their time.

spectral properties aren't the issue.

Of course it is, unless the AA filter has none. The light which
determines the RGB image has to bass through the filter and some must
be lost on the way.

the only thing that's lost is *spatial* *detail* above nyquist (and a
little below since this is the real world).

below nyquist, there is no effect, and a grey card or other test target
has essentially no detail, so it's *well* below nyquist.

if they were shooting resolution test charts or scenes with fine
detail, there would be a difference, as one would expect, but they're
not, at least not in this test.

you claim that dxo is shooting grey cards in their testing, which does
not have detail anywhere close to nyquist, therefore the presence or
absence of an aa filter will have no effect whatsoever.

You are not even reading what I say! I said nothing of the sort but I
have several times stated what it is that DxO do. Now you seem to be
arguing without having read or understood what it is you are arguing
about.

actually, i am reading what you say, which is well beyond ludicrous at
this point.

dxo claims that the d800 has 14.4 stops dynamic range and the d800e has
14.3 stops.

Even ignoring error bars, this is not at all surprising.

it's very surprising that two identical sensors (other than an aa
filter, which has no effect except for aliasing) in identical cameras
with identical electronics have different results, without any
explanation as to why.

That it has no effect except for aliasing is classic nospam.

no, it's classic signal theory 101.

So if it's not in the equation it doesn't exist? The map is not the
territory.

an antialias filter doesn't change the dynamic range of the sensor.
it's that simple.

nor does a uv filter on the lens or different lens for that matter.

are you running out of straws yet?

It
reminds me of the discussion when you assumed that in Windows the
'print' function sent a file straight to the printer without anything
going on in between. In fact all kinds of things may be going on as
well the one thing that you have in mind.

diversion, lying about what i actually said and irrelevant.

It's typical of what you do.

further lying.

you're *really* grasping at straws.

You don't even seem to have the right straws.

you're the one grasping at straws, so grasp whatever type of straw you
prefer.

best to avoid plastic straws, since many places are starting to ban
them.

just don't attack anyone in doing so:
https://www.cnn.com/2019/01/02/us/cu...lds-employee/i
ndex.html

In article , Eric Stevens
wrote:

My lenses are not calibrated in EVs.

actually, they're calibrated in 1/3 evs, unless they're old, when it
wasn't possible to be that accurate.

Further, lenses do not determine EVs on their own. It is also
necessary to set a shutter speed.

and iso.

You say that my lenses are calibrated in EVs and then agree there are
factors additional to the lens which determine EV. Is my lens somehow
prescient or are you an idiot?

ad hominem.

You mean there is another choice?

yes.

If I accept what you say its got to
be one or the other.

no.

Excellent. What is it?

Oh I know. You have already explained.

yes i have. at least you got that part right.

In article , Eric Stevens
wrote:

EV's are equivalent to stops for any purpose related to exposure.

I can change exposure value without changing the stop setting.

No ****. That's sort of the point.

It's my point. Stops aren't exposure values. Exposure values are not
stops.

they are.

Lets leave it at that.

ok, but you saying so doesn't make it correct.

Allright then. Please explain to your readers how you set a lens to an
EV of 20.

For what ISO and speed?

No, no. No ISO or speed. The lens calibration is equivalent to stop
settings according to nospam so it must be possible to set a lens to a
particular EV. I picked 20 as an example.

by picking 20 (or any number), you demonstrate you don't understand it.

Now if I said, for example f/11 you would understand it. But that is
not an EV.

as i said, you don't understand it.

here's a hint:
what's the difference between f/8 and f/11 ?

On 2019-01-12 11:22, nospam wrote:
In article , Eric Stevens
wrote:

Now if I said, for example f/11 you would understand it. But that is
not an EV.

as i said, you don't understand it.

here's a hint:
what's the difference between f/8 and f/11 ?

a) f/3
b) 1 stop
c) 1 EV
d) a and b.
e) b and c.

C'mon _E_ric!
I'm rooting for you!

--
"2/3 of Donald Trump's wives were immigrants. Proof that we
need immigrants to do jobs that most Americans wouldn't do."
- unknown protester

On Fri, 11 Jan 2019 23:21:42 -0500, nospam
wrote:

--- snip ---

The fstop is [Image distance]/lens aperture.

also wrong. f/stop = focal length/aperture.

Aha! Your correction of me is an approximation.

it's not in any way an approximation.

See
https://en.wikipedia.org/wiki/F-number

from that link,
The f-number of an optical system (such as a camera lens) is the
ratio of the system's focal length to the diameter of the entrance
pupil.

exactly what i said it is.

"... as one focuses closer, the lens' effective aperture becomes
smaller, making the exposure darker. The working f-number is often
described in photography as the f-number corrected for lens
extensions by a bellows factor. This is of particular importance in
macro photography".

selective snipping. that's *not* cool.

Do you think I should not have snipped the several thousand irrelevant
words, tables and images between the two parts I quoted? At least I
marked that I snipped.

that quote is from the working f-number section,
https://en.wikipedia.org/wiki/F-number#Working_f-number

For what it is worth, I have never heard of the term 'working
f-number'. I have always known of it as 'effective f-number'.

which begins:
The f-number accurately describes the light-gathering ability of a
lens only for objects an infinite distance away. This limitation is
typically ignored in photography, where f-number is often used
regardless of the distance to the object.

note this part: 'this limitation is typically ignored in photography'.

But not if you are trying to pin me down on an exact definition. As
the Wiki says, the f value is normally calculated on the basis of the
focal length i.e with the lens focused at infinity. That's fine for
characterising a lens and not bad either for exposure calculation
providing the subject is not too close. But if you are being exact,
for exposure calculation purposes, the f value has to be based on the
actual image distance (not just the image distance when focused at
infinity).

did you somehow miss that part?

No I didn't, but we are currently discussing precise meanings, not
conventional abbreviations of terms.

it's ignored for a very good reason: the difference is insignificant,
except in certain situations, namely macro. see below.

moving on,
In optical design, an
alternative is often needed for systems where the object is not far
from the lens. In these cases the working f-number is used.

which is not relevant here.

It's precisely relevant as that is the definition I gave you. What's
more, for photographic purposes it is always accurate.

{formula snipped}

In photography this means that as one focuses closer, the lens'
effective aperture becomes smaller, making the exposure darker.
The working f-number is often described in photography as the
f-number corrected for lens extensions by a bellows factor. This is
of particular importance in macro photography.

not exactly.

Depends upon how exactly you manage your photography.

as one focuses closer, the effective *focal* *length* becomes *longer*,
however, it's not enough to matter in typical situations.

for macro, where the working distance is very short, the effective
focal length can become quite long, requiring lens extensions (tubes,
bellows, etc.).

http://www.nicovandijk.net/pb6E.jpg

focusing closer can also be done via a close-up lens, which will have
no effect on the f/stop. however, it's an additional optical element in
the path and most of them aren't all that good.

tl;dr you're *really* grasping at straws.

A quote from Hamlet's Mill is appropriate:

"In other words we must take language seriously. Imprecise language
discloses the lack of precision of thought."
--

Regards,

Eric Stevens

On Fri, 11 Jan 2019 23:21:41 -0500, nospam
wrote:

In article , Eric Stevens
wrote:

If you want to continue arguing to the contrary I will be happy to
leave you to it.

Reciprocity games. "Introduction to photography 101."

You are still missing the point: lens aperture, shutter speeds or ISOs
are not identical to stops.

I have not missed any points at all. To a PHOTOGRAPHER your PEDANTRY is
MEANINGLESS and in fact MISLEADING.

To some photographers ... it is annoying. But it is amazing what I
have learned out of this thread.

what's amazing is that it doesn't appear that you've learned a thing,
despite repeated explanations from several people.

I apologise for not embracing the full scope of your range of
knowledge but defective as it is my memory will not let me forget what
I already know and understand.
--

Regards,

Eric Stevens

On Sat, 12 Jan 2019 09:26:28 -0500, Alan Browne
wrote:

On 2019-01-11 18:20, Eric Stevens wrote:
On Fri, 11 Jan 2019 12:51:28 -0500, Alan Browne
wrote:

On 2019-01-11 10:28, nospam wrote:
In article , Eric Stevens
wrote:


The problem is clearly DXO's testing methods. No matter how you look
at this, you have to be able to imagine all kinds of sources of
inaccurate measurements, especially if they are slight. I have to
agree with nospam and Alan. You can't get DR outside of the limits of
the ADC because that is the output you see, but you can certainly get
test results outside of that limit.

But the digital DR of the output of the ADC is not the same as the
analog DR of the sensor. Nor is there any reason why it should be.

nobody said it was, however, it's always going to be limited by the adc.


Got that Eric?

What is 'it'? The DR of the sensor or the DR of the output of the ADC?

Obvious. The ADC is the limiting factor. Always. There is NO WAY for
DxO to probe the sensor directly (and it would be meaningless to
everyone even if they could...)

The ADC won't be the limiting factor if it has a better dynamic range
than the sensor.

I think at this point I should stop and ask you whereabouts in the
pipeline the sensor DR range should be measured. As perhaps an extreme
example, do you think it should be measured by what is output to a
memory card? ... or should it be closer to the sensor? If so, where
(and how)?
--

Regards,

Eric Stevens

On Sat, 12 Jan 2019 11:22:30 -0500, nospam
wrote:

In article , Eric Stevens
wrote:

The problem is clearly DXO's testing methods. No matter how you look
at this, you have to be able to imagine all kinds of sources of
inaccurate measurements, especially if they are slight. I have to
agree with nospam and Alan. You can't get DR outside of the limits of
the ADC because that is the output you see, but you can certainly get
test results outside of that limit.

But the digital DR of the output of the ADC is not the same as the
analog DR of the sensor. Nor is there any reason why it should be.

nobody said it was, however, it's always going to be limited by the adc.

The recorded output of the ADC is limited by the capabilities of the
ADC. But these have no effect on the capabilities of the sensor.

again, nobody said the adc would alter the sensor's capability.

You have been strenuously arguing that it will limit it.

as has everyone else, because it does.

A meat grinder will alter a sheep. But before the grinder the sheep
will remain a sheep and after the grinder the sheep will be whatever
the grinder produces. If you are going to determine the height of a
sheep would you prefer to do it before or after the grinder?

You will argue that this is irellevant, but it's not. The place to
measure the DR of a sensor is at the sensor and not at the output of
an ADC. DxO's method measures the DR at the sensor.

you're confusing limiting with altering (and a lot more).

I have been
pointing out that that is not necessarily the case.

it's always the case, except perhaps with your imaginary cameras that
don't exist.

what you still fail to grasp is that whatever the sensor can produce
will always be limited by the adc, unless the sensor itself is the
limiting factor, which is not the case in a d800 class camera.

It depends by what you mean by 'limited'.

no

The sensor will always do do
whatever it can do and it's DR can be scaled up or down to fit the
output bandwidth of the ADC. It is because of the scaling that you can
have the output of a sensor with a 14.8 stop DR scaled down to to suit
a 14 bit ADC. It's not a big deal.

except that it's *not* scaled.

Of course it is. In any sensible design the DR of the input to the ADC
will be designed to accept the DR of the sensor's output.

imaginary cameras do not count.

I don't know where you keep finding these imaginary cameras.

If
the sensor can discriminate between luminance levels from 'c' to 'q'
it will always retain that ability irrespective of the capabilities of
the ADC. How the ADC encodes it is another matter, and how that image
is decoded by RAW decoder is another matter again. There is enormous
scope for fiddling and adjustments.

except that no fiddling or adjustments are being done.

You would know that if you worked for the right section of Nikon. Or
perhaps you have reverse engineered a D800? You will also have to know
what goes on in the Nikon RAW decoder. So I don't actually believe you
know.

there is no need to work for nikon to know that the sensor directly
feeds the adc. your own links even confirmed that in a block diagram.

Is there any argument about that?

if this was not the case, the 'fiddling' would be well known since the
camera would perform differently than previous cameras, ...

But they do, they do

... and it would
likely be marketed as a benefit (e.g., 'new hdr sensor'), and hotly
argued because the camera is 'not pure' or some such.

It is merely your assumption that every individual design advance
would be trumpeted by the marketing department.

and if it really *is* the sensor they're measuring, then it should be
the *same* for the *same* sensor, and it is not.

Not when you shove another piece of glass in front of one of the
sensors.

no effect on dynamic range.

So you keep saying. That doesn't make it true.

it's true because it is true.

No glass (or in this case the material of the AA filter) offers 100%
transmissability to the electromagnetic spectrum. You continuing to
argue otherwise is plain silly.

Nor when you realise that not all sensors will be identical
and all measurements are subject to errors.

especially when the methodology is itself an error.

How can it be an error when they make clear what they are testing and
how?

when their numbers defy physics.

But they don't. In spite of multiple lengthy explanations, the
understanding of how it is that sensor DRs can exceed 14 stops
continues to allude you. Such a failure on your part would be less
understandable if you had not given evidence that you have neither
properly read nor understood the explanations put before you.

if they're supposedly measuring the sensor's dynamic range, explain why
the nikon d50 & d70 differ by a half-stop, both of which used the same
popular 6mp sony sensor (as did pentax). other results also differ.

I have no way of knowing but the first thing I would suspect is the
circuitry between the sensor and the ADC.

then you'd be wrong. there is nothing between the sensor and adc, in
those two or any other camera under discussion.

Do you know whether the ADC is pipelined, or perhaps Nikon use one ADC
per column of pixels? In any case, do you know whether the voltage
divider resistors all have the same value? That the sort of thing
which Nikon's competitors would like to know. For that matter, is the
ADC the same in each camera under discussion? I'm afraid I don't share
your confidence in your certainty.

none of that is in any way relevant.

It is to the illumination of your knowledge of the workings of Nikon
digital cameras.

you're just spewing buzzwords hoping to fool people.

the d50 & d70 are basically the same camera, with minor feature
differences, such as the d70 having two control wheels versus one,
compact flash versus sd card, slightly faster frame rate, wired remote
option, flash commander mode and some minor other things i don't
remember, none of which have *any* effect on the dynamic range.

If you examine first
https://imaging.nikon.com/lineup/dslr/d50/index.htm and then
https://imaging.nikon.com/lineup/dslr/d70/ you will see that the D70
boasts of:

"New Nikon DX Format CCD image sensor for 3,008 x 2,000-pixel images

New advanced digital image processor to optimize image quality,
control auto white balance, auto tone and color control"

that's just marketing babble.

Actually you could be right. I see the D70 preceded the D50 by some 16
months and what was new for the D70 was old hat for for the D50. But,
nevertheless, I would be surprised if 16 months of development did not
result in the slight improvement of the sensor DR range shown by the
D50.




both cameras use the same sony 6mp sensor, which was also used in
several other cameras at the time, including the nikon d100 and d40 as
well as the horribly named pentax *ist.

I would expect the D70 and D50 to have different characteristics.

as i recall, the jpegs were slightly different at default settings, but
that's *after* the adc, it does not apply to raw images and definitely
not a factor for dynamic range of the sensor.

you are claiming the properties of the sensor is what matters, so the
same sensor would have the same properties regardless of camera. any
differences would be in the camera itself, which you are excluding.
--

Regards,

Eric Stevens

On Sat, 12 Jan 2019 09:25:23 -0500, Alan Browne
wrote:

On 2019-01-11 18:18, Eric Stevens wrote:

The recorded output of the ADC is limited by the capabilities of the
ADC. But these have no effect on the capabilities of the sensor. If

If there is no way to encode the information, then that is the mootest
of moot points.

That may well be but, as I have several times said, it is possible to
scale the dynamic range of the sensor to fit the narrower dynamic
range of the ADC.
--

Regards,

Eric Stevens