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

On Fri, 11 Jan 2019 21:30:23 +1300, 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.

DXO's results are at best misleading, whether it's malicious or not.

On 2019-01-10 22:52, Eric Stevens wrote:
On Thu, 10 Jan 2019 07:39:32 -0500, Alan Browne
wrote:

On 2019-01-10 04:05, Eric Stevens wrote:

According to nospam they are claiming a DR of 14.3 for the sensor of
the D800. As they said in the link that I posted which has somehow got
snipped "Maximum dynamic range is the greatest possible amplitude
between light and dark details a given sensor can record ...".

1. A 14 bit sensor cannot, possibly, record 14.3 DR.

Please read what I am about to write and give it deep consideration
before you reply.

_There_is_no_such_thing_as_a_14_bit_sensor_! Or a 12 bit for that
matter. The sensors which we are considering are *analog* devices
which are not digital in their operation.

12 or 14 bits only come into it after the analog signal is stripped
from the sensor and (only then) passed through an analogue to a
digital convertor (ADC).

Now you're being silly.

The whole point of the ADC is to sample the analog sensor.

Constrain that to 14 bits and that's all you get. The whole point of
"more bits" in the ADC is not to find "bright" signal, but to sample
down deep in the very smallest shreds of the darkest part of the signal.

Even if the sensor itself were capable of more than 14 bits of real
honest to goodness signal (not including noise) then declaring a camera
as being more sensitive than its ADC can deliver is plain wrong (not to
mention: noise).

Point is the engineers (most probably) put in an ADC that sampled a
slight more deeper than the practical DR of the analog sensor - ie: they
KNOW that anything deeper is just plain random numbers (aka: NOISE).

Stop being silly. It's actually hurting me.

TANSTAAFL.
3
--
"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 2019-01-10 22:55, Eric Stevens wrote:
On Thu, 10 Jan 2019 07:41:14 -0500, Alan Browne
wrote:

On 2019-01-10 04:08, Eric Stevens wrote:
On Tue, 8 Jan 2019 08:29:29 -0500, Alan Browne
wrote:

On 2019-01-08 04:02, Eric Stevens wrote:

Theey do not specify their algorithms in the article.

Exactly.

So?

Not clear enough, huh? They don't show their algorithms (proprietary, I
assume). OTOH, the claim of 14.3 DR in the face of a 14 bit sensor and
no apparent accounting for noise is bad fish.

That clear enough?

EOD for me.

Please read my latest response and consider ...

I just did and you're grasping at straws.

--
"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 2019-01-10 23:04, Eric Stevens wrote:
On Thu, 10 Jan 2019 07:44:43 -0500, Alan Browne
wrote:

On 2019-01-10 04:17, Eric Stevens wrote:
On Tue, 8 Jan 2019 08:32:40 -0500, Alan Browne
wrote:

On 2019-01-08 04:04, Eric Stevens wrote:
On Mon, 7 Jan 2019 16:57:44 -0500, Alan Browne
wrote:

On 2019-01-07 16:19, Eric Stevens wrote:
On Sun, 6 Jan 2019 10:13:09 -0500, Alan Browne
wrote:

On 2019-01-04 18:58, Eric Stevens wrote:
On Fri, 4 Jan 2019 16:16:05 -0500, Alan Browne
wrote:

On 2019-01-02 04:16, Eric Stevens wrote:
On Wed, 2 Jan 2019 07:48:13 +0000, RJH wrote:

On 02/01/2019 01:38, nospam wrote:
In article , Eric Stevens
wrote:

You are obviously wedded to 1 stop per bit. Why is that?

math.

Why for example can you not have 2 stops per bit, or pi stops per bit?
As long as you scale the entire brightness range with the available 14
stops.

because it doesn't work that way.

think about what a stop means.


FWIW, I don't follow the linearity - in fact I've often wondered why
aperture, ISO and shutter speed aren't infinitely variable, especially
with digital. This article takes me closer to understanding:

https://expertphotography.com/understanding-fstops-stops-in-photography-exposure/

The author of that article is using 'stop' when he should be using
'exposure value'. But lets not get into that in this thread. It's
confused enough already. :-)

There is no difference at all between an EV and a stop of any of the
three independent variables of ISO, exposure period and aperture.

It may be hair-splitting but none of my lenses are calibrated in EVs.

They most definitely are, and probably 1/2 or 1/3 steps of EV as well, [1] ---
or possibly very fine steps in speed priority or auto modes.

I bow to your superior knowledge of my equipment.

Do your lenses have stops?

Yes.

Exactly. So they are indeed calibrated in EV. ([1] above).

No. EVs can be deduced. See
https://en.wikipedia.org/wiki/Exposure_value

"In photography, exposure value (EV) is a number that represents a
combination of a camera's shutter speed and f-number, such that all
combinations that yield the same exposure have the same EV (for any
fixed scene luminance)."

Finding some convenient words doesn't obviate the facts. Your camera
and lenses are calibrated in EV. What words are used (stops for
example) do not matter at all.

Dear me! I can change the EV to which my camera is set without
changing the lens aperture. My lenses are not calibrated in EVs.

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

Wow! You could pass Photography 101, chapter 3 (Basics of exposure).

CONGRATS!


--
"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 2019-01-10 23:11, Eric Stevens wrote:
On Thu, 10 Jan 2019 07:45:09 -0500, Alan Browne
wrote:

On 2019-01-10 04:20, Eric Stevens wrote:
On Tue, 8 Jan 2019 08:38:02 -0500, Alan Browne
wrote:

On 2019-01-08 04:12, Eric Stevens wrote:
On Mon, 07 Jan 2019 23:42:08 -0500, nospam
wrote:

In article , Eric Stevens
wrote:


It may be hair-splitting but none of my lenses are calibrated in EVs.

They most definitely are, and probably 1/2 or 1/3 steps of EV as well,
or possibly very fine steps in speed priority or auto modes.

I bow to your superior knowledge of my equipment.

your equipment is nothing special. many people have the same stuff.

for modern lenses, it's user selectable at 1, 1/2 or 1/3 stops. not all
options may be available on all cameras. it appears that nikon no
longer offers 1 stop anymore (there's no reason to) but older nikon
slrs did. i assume canon, pentax, etc., are similar.

examples:
https://www.imaging-resource.com/PRODS/D7000/screens/DSC_0211.jpg
https://1.img-dpreview.com/files/p/a...ages/Captures/
d1x_41.gif
http://www.steves-digicams.com/2004_reviews/d70/d70_custom_menu2.jpg

for older lenses with a mechanical aperture ring (manual lenses and
early autofocus), the aperture ring will normally click at 1 stop
increments, sometimes 1/2 stop. occasionally, it's both on the same
lens, i.e., the widest and smallest are 1 stop, rest 1/2 stop. there is
no point in 1/3 stops since the mechanics aren't good enough.

some lenses, such as mirror lenses, have only one f/stop, with no
adjustments to be made, although they sometimes accept an nd filter in
the back.

This illustrates the disadvantage of not using the language with
precision. As I said, all my lenses make use of f/numbers which are a
measure of stops. Your thoughts have jumped the rails and are now
talking about the intervals of Exposure Value of which the camera is
capable. The exposure value may be used to set lens aperture, shutter
speed or ISO. They are not identical to stops.

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. Lets leave it at that.

Yes, you should.


--
"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 2019-01-10 23:36, Eric Stevens wrote:
On Thu, 10 Jan 2019 07:46:00 -0500, Alan Browne
wrote:

On 2019-01-10 04:22, Eric Stevens wrote:
On Tue, 08 Jan 2019 10:28:28 -0500, nospam
wrote:

In article , Eric Stevens
wrote:

It may be hair-splitting but none of my lenses are calibrated in EVs.

They most definitely are, and probably 1/2 or 1/3 steps of EV as well,
or possibly very fine steps in speed priority or auto modes.

I bow to your superior knowledge of my equipment.

your equipment is nothing special. many people have the same stuff.

for modern lenses, it's user selectable at 1, 1/2 or 1/3 stops. not all
options may be available on all cameras. it appears that nikon no
longer offers 1 stop anymore (there's no reason to) but older nikon
slrs did. i assume canon, pentax, etc., are similar.

examples:
https://www.imaging-resource.com/PRODS/D7000/screens/DSC_0211.jpg
https://1.img-dpreview.com/files/p/a...ages/Captures/
d1x_41.gif
http://www.steves-digicams.com/2004_reviews/d70/d70_custom_menu2.jpg

for older lenses with a mechanical aperture ring (manual lenses and
early autofocus), the aperture ring will normally click at 1 stop
increments, sometimes 1/2 stop. occasionally, it's both on the same
lens, i.e., the widest and smallest are 1 stop, rest 1/2 stop. there is
no point in 1/3 stops since the mechanics aren't good enough.

some lenses, such as mirror lenses, have only one f/stop, with no
adjustments to be made, although they sometimes accept an nd filter in
the back.

This illustrates the disadvantage of not using the language with
precision. As I said, all my lenses make use of f/numbers which are a
measure of stops. Your thoughts have jumped the rails and are now
talking about the intervals of Exposure Value of which the camera is
capable. The exposure value may be used to set lens aperture, shutter
speed or ISO. They are not identical to stops.

they absolutely are.

So I double the shutter speed. I have halved the exposure value but I
haven't affected the stop setting.

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.


--
"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 2019-01-10 23:38, Eric Stevens wrote:
On Thu, 10 Jan 2019 07:43:24 -0500, Alan Browne
wrote:

On 2019-01-10 04:12, Eric Stevens wrote:
On Wed, 9 Jan 2019 08:36:24 -0500, Alan Browne
wrote:

Its amazing what Google can produce. This is DxO's own account of the
situation at:
https://www.dxomark.com/dxomark-came...ol-and-scores/

"Dynamic range corresponds to the ratio between the highest
brightness a camera can capture (saturation) and the lowest
brightness it can capture (which is typically when noise becomes
more important than the signal — that is, a signal-to-noise ratio
below 0 dB). A value of 12 EV is excellent, with differences below
0.5 EV usually not noticeable. Dynamic range is an open scale."

This appears to confirm that the situation is as I deduced: they are
not testing the dynamic range as recorded in a raw file. They are
testing the range that a camera can capture. i.e. it is the dynmaic
range of the sensor. It is not the dynamic range of the raw file.

It doesn't actually say that, however.

How, specifically, are they bypassing the raw file to get the data?


By measuring not the data in the file but the range of brightness that
the camera can capture from their test set up.

And where _specifically_ are they getting that data? What is the probe
point? What is the probe?

Read the URL. The use multiple light sources, each of different
calibrated illuminance. It's rather like photographing an gray-scale
wedge.

Oh. Thanks. Now it's CLEAR TO ME YOU HAVE NO CLUE.

My question related to how they measure the brightness at the camera.

And you're not replying with an answer to that. At all.

--
"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 2019-01-10 23:45, Bill W wrote:

_There_is_no_such_thing_as_a_14_bit_sensor_! Or a 12 bit for that
matter. The sensors which we are considering are *analog* devices
which are not digital in their operation.

12 or 14 bits only come into it after the analog signal is stripped
from the sensor and (only then) passed through an analogue to a
digital convertor (ADC).

A 14 bit ADC can output 16,384 distinct numerical values and the
analog output of the sensor has to be mapped to this range. It doesn't
matter what the Dynamic Range of the sensor may be. It has to be
mapped to the numerical scale of the output of the ADC. It is
perfectly feasible to map an analogue dynamic range to 14 bits (o12
(or 8)). Not withstanding what else has been written in this thread
the choice of the number of bits used to encode the sensor's output
does not affect the _sensor's_ dynamic range.

But the issue is not the sensor's DR, it's the camera's DR. The output
of the camera is the output of the ADC - not the sensor, and that ADC
is limited to 14 stops as designed.

This.


--
"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 2019-01-11 03:46, Eric Stevens wrote:
On Fri, 11 Jan 2019 00:18:28 -0500, nospam
wrote:

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?

That's the whole nutshell. Done. Period.

--
"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 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?


--
"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