Lightroom vs. Apertu Curves

On Tue, 12 Aug 2014 19:12:17 -0400, nospam
wrote:

Also "everything is done in raw" is just not true.

you're wrong. it is true.

that's how lightroom (and aperture) works.

That is an abjectly ignorant statement.

it's 100% accurate. that's how they work.

That doesn't make sense. If everything was done in raw then you would
need a different processing engine for each type of raw image. What
happens is that the raw image (from whatever camera) is converted into
the type of colour space used by the editor.

According to http://en.wikipedia.org/wiki/ColorSync the Profile
Connection Space (PCS) used by Apple is CIE XYZ Color Space.

According to
http://www.dpbestflow.org/color/colo...color-profiles
"Photoshop uses CIELAB as a reference color space when it converts
from one RGB profile to another RGB color space. Photoshop uses CIE
XYZ when it converts from the RGB color mode to the CMYK color mode".
I haven't been able to find a statement specific to Lightroom but it
does seem likely that Lightroom uses the same PCS as Photoshop.

CIELAB is commonly referred to as L*a*b* or even more commonly as Lab.
CIELAB is closely related to CIE XYZ so there is no great difference
between the PCS used by Photoshop and that used by Apple.

No matter what, the processing inside the editor is not done in raw.
--

Regards,

Eric Stevens

On Tue, 12 Aug 2014 18:36:25 -0700, Savageduck
wrote:

On 2014-08-13 00:37:53 +0000, (Floyd L. Davidson) said:

Savageduck wrote:
On 2014-08-12 22:25:42 +0000, (Floyd L. Davidson) said:

nospam wrote:
In article , Floyd L. Davidson
wrote:
But if it has been converted, and is now being
edited...
it hasn't been converted. all adjustments are applied
to the raw data.
Hilarious.

Actually Floyd, this time *nospam* is sort of, but not entirely correct.

He isn't even close. He is making wild statements that
are so confused compared to reality that it is actually
obnoxious to have someone confusing others.

Most of us who use Lightroom, import RAW files and we
choose to either maintain them as original RAW files, or
convert to DNG. All edits/adjustments are applied to
those imported, unconverted RAW files. All of these
adjustments/edits are recorded and stored in the
Lightroom data base as XMP files.

Those adjustments are *never* applied to the raw sensor
data. They are applied to the RGB data produced by
converting the Bayer Color Filter Array encoded color to
RGB encoded color.

In Lightroom there is no conversion of the RAW file until the adjusted
image file is converted for use in an external editor.
For those RAW files not converted they, remain unmolested and the
adjustments and edits are retained in XMP files.

You can't be sure of that and in fact I think you are wrong. Lightroom
won't have the capability to understand and then edit the geometry and
colour interpretation of each and every one of all the raw images it
is able to import. What it will do is import the raw file through an
interpreter (for which it has the data) and transform it into it's own
internal working space. This happens every time you load a raw file.
It is this version of the image which is open to modification by
Lightroom's editing functions and to which the XMP files apply.

I usually make my adjustments to a "Virtual Copy" of the
imported original, and I can have several virtual copies
each as a different rendition.

Irrelevant.

I guess so, just my workflow.

there is no jpeg until the user exports one, and that's if they decide
to do that. they might not, which means there won't ever be a jpeg.

Also "everything is done in raw" is just not true.
you're wrong. it is true.
that's how lightroom (and aperture) works.
That is an abjectly ignorant statement.

I have no JPEGs in Lightroom, I only produce JPEGs from
NEFs, DNGs, PSDs, and TIFs in Lightroom when I use the
LR export dialog and use one of my presets to resize,
convert to 8-bit JPEG, and sRGB to store in the location
I choose.

Irrelevant to the discussion.

Not really.

Here is that export dialog, and as you can see I have
quite a few options including file type, size,
dimensions, color space, levels of metadata I can
include, etc.

What you can export is of no significance.

Ok.

What can you import? (Not what *do* you import, but what *can* you
import.)

NEF, CR2, RAF, AFW, DNG and other RAW files in addition to all the
usual suspects JPEG, JPEG2000, PSD, TIFF, PNG, GIF, et al.

So in this case the 108 MB, ProPhoto RGB, 4952x3569,
_DNC2923-edit.tif is exported to my Dropbox Public
folder as the 817kb, sRGB, 1304x940,
_DNC2923-edit-1.jpg
https://dl.dropbox.com/u/1295663/FileChute/screenshot_842.jpg
https://dl.dropboxusercontent.com/u/1295663/_DNC2923-Edit-1.jpg

All the adjustments made in Lightroom are to RAW files

But that is not the issue, though you aren't quite correct
anyway.

Well all the adjustments I make in Lightroom are made to the RAW file.

All color, brightness, and gamma adjustments are made to
an RGB data set. You are saying that your workflow
always involves deriving the RGB data set from a RAW
file that is first converted.

I didn't say that. I apply the adjustments to an unconverted RAW file,
for all of its life in my Lightroom library it remains the same
unmolested RAW file with th adjustments recorded in an XMP file. It is
converted if I choose to use an external editor.

What was claimed is that the adjustments are applied to the raw sensor
data from
the RAW file *before* it is converted to RGB data. That
does not happen with anything relating to color.

In Lightroom it does.

unless an external processor such as Photoshop has been
used then Lightroom acts as a RAW processor and
converts, usually to 16-bit TIF with a preferred color
space of ProPhoto RGB. A TIF, or PSD would be saved back
to Lightroom from the external editor.

Yes, but that isn't what is at issue.

If you don't want it to be, so be it.

There is
not color space for raw sensor data either.
the colour space used is pro photo rgb.
Not for raw sensor data it isn't.

ProPhoto RGB is recommended for use by Lightroom when it
is used to convert an adjusted RAW file for use in an

It is applied to RGB image data, not to the RAW file's
raw sensor data. The fact that it was used might get
written to the RAW file, but the RGB image data is never
written back to the RAW file (by external converters, as
opposed to the in camera RAW converter that does embed
JPEG images).

Agreed, the RAW file remains intact as it was imported. The adjustments
are applied to and recorded in an XML file much as they would be in ACR
prior to conversion.

external editor such as Photoshop, or any of a number of
plug-ins which Lightroom sees as external editors. There
is no colorspace reference when editing/adjusting RAW
files in Lightroom/ Any JPEGS which find their way to LR
are adjusted in the colorspace that was used in their
creation.

Or converted...

Whatever.

One other area where *nospam* is correct, is you have no idea of how
Lightroom functions, or just how folks use it either as a primary
editor, or as a RAW convertor, or both. These days I seldom use ACR in
my RAW workflow except as a Photoshop filter
--

Regards,

Eric Stevens

nospam wrote:
In article , Floyd L. Davidson
wrote:
i'm correct that it does have a colour space for its raw calculations.

It need not, and indeed cannot, have a color space for
"raw calculations". Color space doesn't mean anything
in relation to raw sensor data.

it does.

learn something for a change:

You posted that before, and as noted then and now, it says exactly
nothing to support you statement. It is all about *RGB* images, and
not about "raw calculations".

https://forums.adobe.com/message/6228569

Melissa RGB is the name of the color space that represents the
histogram and RGB values in Develop (soft proofing off). This is not
the same color space used for processing. Melissa RGB uses ProPhoto
primaries with an actual 2.2 Tone Response Curve (TRC) like sRGB's
TRC. The internal processing space is a linear (1.0 TRC) space with
the same ProPhoto RGB primaries. This internal color space has no
name.

the key sentence is:
The internal processing space is a linear (1.0 TRC) space with
the same ProPhoto RGB primaries. This internal color space has no
name.

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

nospam wrote:
In article , Floyd L. Davidson
wrote:


"All adjustments" are applied *after*
the data is demosaiced. It *cannot* be appled to the raw data.

the demosaicing is a step that's automatically included and your
nitpicking does not change anything.

it is *not* a separate step as far as the user is concerned (which is
all that matters).

Sure it isn't.

it isn't.

the user imports a raw, adjusts and exports the results. there is no
conversion to anything intermediate. the raw stays raw the entire time.

The raw sensor data is not adjusted nor edited. It is
only converted to RGB and that is the data set worked
on.

You are claiming that because you don't know what goes
on inside, that nothing goes on inside.

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

In article , Floyd L. Davidson
wrote:

Those adjustments are *never* applied to the raw sensor
data. They are applied to the RGB data produced by
converting the Bayer Color Filter Array encoded color to
RGB encoded color.

In Lightroom there is no conversion of the RAW file
until the adjusted image file is converted for use in an
external editor.
For those RAW files not converted they, remain
unmolested and the adjustments and edits are retained in
XMP files.

No conversion until after the data that doesn't exist is
adjusted????

Come on... let get really silly.

The RAW file is never "molested", but the data from the
file is used to generate an RGB data set. That is what
demosaicing means. Until that RGB data set exists there
is no image to view and no data to "adjust" with things
like brightness, gamma curves, and color space. The
first step is necessarily to convert raw sensor data to
RGB pixel data.

internal and unimportant to users.

this is where you are stuck.

The "adjusted image file" is *never* "converted" for
anything in the same sense that "converted" is used to
describe demosiacing the raw sensor data. The values of
the image pixels are not changed, they are formatted in
a given way. With raw sensor data there are no pixel
values and the data values that are "converted" do not
have the same value or even meaning in a new format.
Instead they have a totally new kind of value (a pixel
value as opposed to sensor location values).

again, internal and unimportant to users.

I have no JPEGs in Lightroom, I only produce JPEGs
from
NEFs, DNGs, PSDs, and TIFs in Lightroom when I use the
LR export dialog and use one of my presets to resize,
convert to 8-bit JPEG, and sRGB to store in the location
I choose.
Irrelevant to the discussion.

Not really.

Absolutely irrelevant. While you don't, the facility
for you to do it that way is there. It makes no
difference whether your workflow uses it or not.

it's relevant in that exporting is part of how lightroom works, and he
does use that capability.

if you actually used lightroom, you'd realize just how stupid what
you're saying actually is.

Here is that export dialog, and as you can see I have
quite a few options including file type, size,
dimensions, color space, levels of metadata I can
include, etc.
What you can export is of no significance.

Ok.

What can you import? (Not what *do* you import, but what *can* you
import.)

NEF, CR2, RAF, AFW, DNG and other RAW files in addition
to all the usual suspects JPEG, JPEG2000, PSD, TIFF,
PNG, GIF, et al.

See! And when you import an NEF or other raw file it
necessarily must be converted to an RGB data set before
any color space or other such adjustment can be made.
None of that is done to raw sensor data, ever.

again, internal and not important to users.

users import the raw, they adjust the images to taste and export the
final images.

what lightroom does internally does not matter except to the authors of
the app.

users want results. they are not modifying the source code

But you can import an image data set without having to
convert it from raw sensor data.

whatever is imported is not converted or modified.

So in this case the 108 MB, ProPhoto RGB, 4952x3569,
_DNC2923-edit.tif is exported to my Dropbox Public
folder as the 817kb, sRGB, 1304x940,
_DNC2923-edit-1.jpg
https://dl.dropbox.com/u/1295663/FileChute/screenshot_842.jpg
https://dl.dropboxusercontent.com/u/1295663/_DNC2923-Edit-1.jpg
All the adjustments made in Lightroom are to RAW files
But that is not the issue, though you aren't quite
correct
anyway.

Well all the adjustments I make in Lightroom are made to the RAW file.

No, the adjustments are made to RGB data. If you input
a RAW file Lightroom cannot do a thing to raw sensor
data until it first converts it to RGB data.

as far as the user is concerned, the adjustments are made to the raw
data.

the fact that lightroom does an rgb conversion is unimportant to end
users. they don't care.

knowing that irrelevant detail is not going to make their photos any
better.

If you input a JPEG that is not the case.

if you import a jpeg, the adjustments are made to the jpeg data.

All color, brightness, and gamma adjustments are made to
an RGB data set. You are saying that your workflow
always involves deriving the RGB data set from a RAW
file that is first converted.

I didn't say that.

That is exactly what you are saying. You just don't realize
that is what happens.

how does knowing that change the results?

it doesn't.

again, you are overcomplicating things for absolutely no reason other
than to argue.

I apply the adjustments to an
unconverted RAW file, for all of its life in my
Lightroom library it remains the same unmolested RAW
file with th adjustments recorded in an XMP file. It is
converted if I choose to use an external editor.

You *cannot* make an adjustment to the raw sensor data.

yet users are doing that millions of times a day, worldwide.

Only to the RGB data set generated from that raw sensor
data by a demosaicing process. Until that has been done
there is nothing to adjust.

again, that's internal and of no concern to end users.

are you going to break it down into processor opcodes?

the user imports raws, adjusts as needed and exports results. that's
all that matters.

What was claimed is that the adjustments are applied
to the raw sensor data from
the RAW file *before* it is converted to RGB data. That
does not happen with anything relating to color.

In Lightroom it does.

It can't.

it does.

unless an external processor such as Photoshop has been
used then Lightroom acts as a RAW processor and
converts, usually to 16-bit TIF with a preferred color
space of ProPhoto RGB. A TIF, or PSD would be saved back
to Lightroom from the external editor.
Yes, but that isn't what is at issue.

If you don't want it to be, so be it.

Where is there an issue?

the issue is that photoshop is inserted into the workflow.

ProPhoto RGB is recommended for use by Lightroom when
it
is used to convert an adjusted RAW file for use in an
It is applied to RGB image data, not to the RAW file's
raw sensor data. The fact that it was used might get
written to the RAW file, but the RGB image data is never
written back to the RAW file (by external converters, as
opposed to the in camera RAW converter that does embed
JPEG images).

Agreed, the RAW file remains intact as it was
imported. The adjustments are applied to and recorded in
an XML file much as they would be in ACR prior to
conversion.

They are not applied to the XML file. What is applied
to the RGB data set is recorded in the XML file.

you're mis-parsing because you don't understand how lightroom works.

One other area where *nospam* is correct, is you have no
idea of how Lightroom functions, or just how folks use
it either as a primary editor, or as a RAW convertor, or
both. These days I seldom use ACR in my RAW workflow
except as a Photoshop filter

Seems that I understand the underlying processes better
than either of you. I hate to be the one to tell you,
but using a software package doesn't help you that much
in knowing how it works.

except that you don't understand it at all.

all you're doing is arguing semantics.

whether or not there's an internal rgb conversion (or even if it's lab)
makes no difference to the user or the results they create.

you are overcomplicating it just to argue.

In article , Floyd L. Davidson
wrote:

my statements are accurate.

Well, lets see...

unfortunately. you can only see what you choose to see.

the user does not make a separate conversion to rgb.

Trivially wrong, and significantly so.

it's not wrong.

the user does not make a separate conversion, exactly as i said.

they import a raw, adjust various parameters and lightroom does the
necessary calculations.

So, obviously the user does cause a conversion to rgb. And it is
not an insignificant step that can be ignored.

causing one to happen internally is not the same as converting it
themselves.

again, the user does not make a separate conversion to rgb, exactly as
i said.

what goes on internally is of no concern to anyone but the authors of
the app.

you are overcomplicating things just to argue.

I have no JPEGs in Lightroom, I only produce JPEGs from
NEFs, DNGs, PSDs, and TIFs in Lightroom when I use the
LR export dialog and use one of my presets to resize,
convert to 8-bit JPEG, and sRGB to store in the location
I choose.

Irrelevant to the discussion.

actually it is relevant.

Not making use of a functionality doesn't mean it isn't there.

nobody said the functionality wasn't there.

however, what's relevant is that lightroom accepts a wide variety of
inputs and uses the exact same workflow to process any of them, which
is a *huge* boon to productivity.

there aren't separate workflows for raw, jpeg, tiff, etc.

i suspect you'll say it's not possible for that to happen, yet it is
and it's one of the more useful aspects of lightroom.

What you can export is of no significance.

it is, because it shows that the data is never converted until it's
exported.

And you make adjustments to what, an image you imagine? Or is
there any chance that you actually do see it? Just maybe it
does exist...

Some of this is just too trivially silly...

only because you can't think beyond what you know.

what it shows on screen prior to exporting are the results of whatever
the adjustment sliders are currently set to.

they can be changed at any time, including un-cropping since everything
is non-destructive.

only when the image is exported are those adjustments baked into the
image that's exported and only the image that's exported.

What can you
import? (Not what *do* you import, but what *can* you
import.)

that does not matter whatsoever.

Sigh.

Another idiocy.

why would the formats that can be imported matter?

they don't.

it's completely irrelevant, and you're only asking because you have no
idea how it actually works.

nevertheless, lightroom can import all known raw file formats, jpeg,
tiff, dng, standard video formats and more.

it doesn't care and the workflow is the same (other than video for
obvious reasons).

Sure, it demosaics JPEG files, but doesn't do that to raw sensor
data... You are so funny.

i never said it demosaics jpeg. where in the world did you come up with
that nonsense?

and don't put words in my mouth.

i said the workflow is the same, and it is.

There were more, but this exchange with you is worthless.

only because you refuse to acknowledge that there are other ways to do
something.

In article , Eric Stevens
wrote:

Also "everything is done in raw" is just not true.

you're wrong. it is true.

that's how lightroom (and aperture) works.

That is an abjectly ignorant statement.

it's 100% accurate. that's how they work.

That doesn't make sense. If everything was done in raw then you would
need a different processing engine for each type of raw image. What
happens is that the raw image (from whatever camera) is converted into
the type of colour space used by the editor.

only one raw engine is needed, which can call the appropriate code for
whatever raw file it gets.

and that's what it does.

lightroom then applies all of the other adjustments the user does,
including exposure, white balance, highlight recovery, etc.

all of that is done on the fly to the raw data and previewed on screen
and ultimately exported (or printed or whatever).

According to http://en.wikipedia.org/wiki/ColorSync the Profile
Connection Space (PCS) used by Apple is CIE XYZ Color Space.

what does colorsync have to do with anything?

lightroom is not an apple product and colorsync is not used.

lightroom has it's own cms.

According to
http://www.dpbestflow.org/color/colo...color-profiles
"Photoshop uses CIELAB as a reference color space when it converts
from one RGB profile to another RGB color space. Photoshop uses CIE
XYZ when it converts from the RGB color mode to the CMYK color mode".
I haven't been able to find a statement specific to Lightroom but it
does seem likely that Lightroom uses the same PCS as Photoshop.

this is about lightroom, not photoshop.

lightroom uses its own color space that's basically pro photo rgb with
linear gamma for calculations. it also uses other spaces for specific
tasks, such as image previews.

CIELAB is commonly referred to as L*a*b* or even more commonly as Lab.
CIELAB is closely related to CIE XYZ so there is no great difference
between the PCS used by Photoshop and that used by Apple.

photoshop doesn't use lab as an internal format.

we discussed this a year or two ago. to use lab as an internal format
would be slow.

No matter what, the processing inside the editor is not done in raw.

nobody said it was.

it's done *to* the raw and rendered on the fly.

In article , Eric Stevens
wrote:

But if it has been converted, and is now being
edited...
it hasn't been converted. all adjustments are applied
to the raw data.
Hilarious.

Actually Floyd, this time *nospam* is sort of, but not entirely correct.

He isn't even close. He is making wild statements that
are so confused compared to reality that it is actually
obnoxious to have someone confusing others.

Most of us who use Lightroom, import RAW files and we
choose to either maintain them as original RAW files, or
convert to DNG. All edits/adjustments are applied to
those imported, unconverted RAW files. All of these
adjustments/edits are recorded and stored in the
Lightroom data base as XMP files.

Those adjustments are *never* applied to the raw sensor
data. They are applied to the RGB data produced by
converting the Bayer Color Filter Array encoded color to
RGB encoded color.

In Lightroom there is no conversion of the RAW file until the adjusted
image file is converted for use in an external editor.
For those RAW files not converted they, remain unmolested and the
adjustments and edits are retained in XMP files.

You can't be sure of that and in fact I think you are wrong. Lightroom
won't have the capability to understand and then edit the geometry and
colour interpretation of each and every one of all the raw images it
is able to import.

of course it can.

anything that's supported by camera raw can be imported and will work.

here's the list:
http://helpx.adobe.com/photoshop/camera-raw.html

What it will do is import the raw file through an
interpreter (for which it has the data) and transform it into it's own
internal working space. This happens every time you load a raw file.

nope.

when you import a file, it creates an alias to the file, adds that info
to the database along with keywords and assorted other information.

if you make an adjustment, it re-renders the image on the fly from the
raw data contained in the file.

it may cache intermediate results for speed but that's just an
optimization.

another optimization is if you're zoomed in, it may not render what's
offscreen until later (or at all should you revert the adjustment).

there's a *****load* going on under the hood and none of it matters to
end users.

It is this version of the image which is open to modification by
Lightroom's editing functions and to which the XMP files apply.

what you're calling a 'version' is the preview image, which is rendered
on the fly from the raw data.

as above, it can be cached for speed and there is a choice as to how
large of a preview it should save.

In article , Floyd L. Davidson
wrote:

i'm correct that it does have a colour space for its raw calculations.

It need not, and indeed cannot, have a color space for
"raw calculations". Color space doesn't mean anything
in relation to raw sensor data.

it does.

learn something for a change:

You posted that before, and as noted then and now, it says exactly
nothing to support you statement. It is all about *RGB* images, and
not about "raw calculations".

the raw calculations are done to the raw data.

what you're calling an rgb image exists only internal to lightroom.


https://forums.adobe.com/message/6228569

Melissa RGB is the name of the color space that represents the
histogram and RGB values in Develop (soft proofing off). This is not
the same color space used for processing. Melissa RGB uses ProPhoto
primaries with an actual 2.2 Tone Response Curve (TRC) like sRGB's
TRC. The internal processing space is a linear (1.0 TRC) space with
the same ProPhoto RGB primaries. This internal color space has no
name.

the key sentence is:
The internal processing space is a linear (1.0 TRC) space with
the same ProPhoto RGB primaries. This internal color space has no
name.

In article , Floyd L. Davidson
wrote:

"All adjustments" are applied *after*
the data is demosaiced. It *cannot* be appled to the raw data.

the demosaicing is a step that's automatically included and your
nitpicking does not change anything.

it is *not* a separate step as far as the user is concerned (which is
all that matters).

Sure it isn't.

it isn't.

the user imports a raw, adjusts and exports the results. there is no
conversion to anything intermediate. the raw stays raw the entire time.

The raw sensor data is not adjusted nor edited. It is
only converted to RGB and that is the data set worked
on.

nitpicking.

again, the user imports a raw file, works on it and does something with
the results, likely exporting but it could just be printed, which
avoids the need to export anything.

what goes on internally is of no concern to anyone but the authors of
the app.

You are claiming that because you don't know what goes
on inside, that nothing goes on inside.

i know exactly what goes on inside, *much* better than you'll ever know.

you have such very little understanding about how lightroom and similar
apps work, so all you can do is nitpick on semantics.