Raw photo software

I'm afraid that all sounds good, but it just is not
true. Yes, it *does* have to re-render *everything* to
get another pre-view image.

You *can't* just remove the white balance and add in
another white balance.

So just how do *you* think it is done. There is one other
way, and I really doubt anyone would write it that way...

Just you. Round and round.

 

You are still evading the question. Does it have any editing
functions?

If not, where does Savageduck get the ability which enables him to
write:

"However, all of the above, including selective processing via the
adjustment brush, sharpening, noise reduction, spot correction,
red-eye correction, spot correction, image alignment, custom &
fixed ratio cropping, color balancing, application of gradients,
application of lens profiles, CA & Vignette corrections, creation
of pre-sets, and more can be done in ACR, either using the CS, or
LR interfaces."

- selective processing via the adjustment brush

- spot correction

- image alignment

- custom & fixed ratio cropping

- application of gradients

- application of lens profiles

- CA & Vignette corrections

- creation of pre-sets

.... are not functions essential to raw conversion. In fact they entail
altering the image in some way and can be done at any stage of the
image _editing_.

 

How do you "remove" white balance?

 

I get the ability to write the above, because all of the above
adjustments/edits are available to the user of CS5 when processing RAW
image files with ACR. I am able to use any of the above listed
adjustments and edits prior to clicking on the "Open" or the "Done"
button.


....or I can hold the shift key down and click on "Open" so that the
adjusted RAW file is opened in CS5 as a 32-bit Smart Object.

True. However, this is the subtle bonus you get by using CS5/6 & ACR.

 

I understand that and am not objecting to your statement in any way.
I'm quoting it as evidence that ACR is more than a raw convertor. I'm
probably the only one still sticking with that as the point of the
argument.

Which was my original point.

 

OK!
You could say that ACR is a RAW convertor on steroids, and Lightroom
wraps it all in a package with a bunch of other stuff, such as print
and presentation options, some serious editing ability, Mapping, and
the ability to use third party plugins, and presets. There are a few
things LR won't do, such as the 32-bit Smart Object conversion, but
that isn't really one of its functions or selling points.

OK!
Time to put it to rest.

 

Either go back to the original raw sensor data, or to the
initial uncorrected RGB data if it has been saved.

Generally that means the RAW converter has to be invoked
again to generate an uncorrected RGB data set.

 

don't apply it.

 

i'm not evading at all.

camera raw is a plug-in. it *can't* be run by itself.

it can only be run within photoshop or lightroom, both of which add
editing functions.

in the case of lightroom, there's no distinction between editing or raw
conversion, nor does it matter. you make the desired change to the
image at any time.

in photoshop, there's a small difference but if you use smart objects,
you can go back to camera raw from within photoshop, just like you can
with an adjustment layer.

he posted a screen shot which shows all of that within camera raw.

 

Yeah right. That's how you know if it is correct, or
too much this or too little that, is you don't apply it
and never know what the effect is.

Some of the silly things you say...

 

Which confirms that it's more than a raw convertor.

 

I'm unsure of what you mean. "White Balance" is a point at which the
color temperature is set. It can be changed, set, and re-set, but I
don't understand how it could be "removed".

If you mean white balance can be re-set in an image, then "removed" is
a poor choice of words to use.

 

What does that mean? Every image has a white balance factor. It is
not added or removed, but it can be changed.

Saying "don't apply it" makes no sense at all in answering a question
about removing something. You can only remove what is there. If it
is never there, it can't be removed. White balance, though, is always
there and cannot be removed. It can be changed, but not removed.

I suspect that you two are muddling about talking about *adjusting*
the white balance by applying the white balance tool in the RAW image.
Not applying that tool does not remove white balance. Setting the
white balance differently from the first application does not remove
white balance.

It's like setting the thermostat in a room. You don't remove the
room's temperature, you change it.

 

White balance is the application of a set of channel
multipliers. If it has not been set, then essentially
the multipliers are all three equal to 1.0. It isn't
actually impossible to "remove" it, but it is not
exactly reversible because of rounding errors. To get
the exact original requires regenerating the original
data.

Incidentally, if the channel multipliers are all set to
1.0, the image will look "sickly green". That is
exactly what something known as UniWB does. If you are
interested, use Google to track down more information
about it.

The only benefit to using 1.0 channel multipliers as far
as I know is that the resulting JPEG image, while it
might be horribly ugly, does produce an histogram that
is very nearly exactly what true "raw histogram" would
be. Since to date no camera manufacturer has yet
decided to generate a raw histogram, using UniWB is a
way to get an extremely accurate histogram. It is
entirely possible to set exposures to within 1/10 of an
f/stop of obtaining the maximum dynamic range for any
given ISO. It requires shoot in RAW mode, as the in
camera JPEG is useless for anything other than generating
an accurate histogram.

 

The "thermostat in a room" analogy is not good. In
essence, if it is used in practice, the results will
be flawed by accumulating rounding errors.

The sensor data in the RAW file that is demosaiced to
form pixel data, which is in a three channel (RGB) 16
bit format, has absolutely no White balance applied.
White Balance is applied to the raw data as it is
demosaiced (it could be applied to the RGB data after
demosaicing, but that reduces precision).

To set any preset "color temperature", the data
necessarily must either not have yet had any channel
multipliers used or those multipliers have to be
removed. That could be done with a custom multiplier to
convert from one multiplier to a different one, but due
to rounding errors the accurate method is to start
without any previous application of multipliers. And by
simply restarting with unaltered data there is no need
to even know what previous WB settings have been used.

The operation to set any given white balance requires
adjusting each of the three channels with a multiplier.
The values differ with each sensor, so each model of
camera has different values of multipliers for any given
"color temperature". Worse yet, just exactly what the
actual "color temperature" is is not well defined
either! There are different accepted ways of
calculating color temperature...

For example, with a Nikon D4 one of the WB presets is
"Cloudy", and if that is set the multipliers are 1.0 for
each of the two Green channels, 2.1778125 for the Red
channel, and 1.30078125 for the Blue channel. The numbers
are recorded in the Exif data with every image.

The Nikon manual says that is a 6000K temperature.
However, the preset for 6000K is very slightly
different, with Red at 2.171875 and Blue at 1.296875.

Regardless, if those are plugged into UFRAW, that
program calculates the color temperature as 5680 for one
and slightly higher for the second. And if UFRAW is set
for 6000K it will use multipliers of 1 for the green
channels, 2.339 for Red and 1.307 for Blue.

All are close enough for most people, but someone who is
doing proofing work needs to know exactly what the
differences are.

As with other raw converter parameters, each time the WB
is changed the preview image will be recalculated to
show the effect. The WB is not adjusted from the last
setting to a new setting, it is simply rendered from the
very beginning. The preview image is not full size, and
the raw conversion can be optimized for speed. When
everything is "finished" a conversion is done at full
size and optimized for quality.

 

This is an election year, so I'm used to a volume of rhetoric that
sounds like it says something, but - when examined - doesn't address
the point at all.

I repeat, "How do you remove white balance"?

In that muddle of rhetoric you seem to saying that there is a default
white balance where all three multipliers are equal to 1.0. My
position is that this can be changed, but it cannot be removed.

 

Please refer to my other post on the subject of a volume of rhetoric
that doesn't address the point. You have added to the volume, but
still have not addressed the simple question: "How do you remove
white balance?"

I congratulate you on the introduction of the problem of rounding
errors in the analogy of changing the temperature by adjusting the
thermostat. You have ascribed an error of precision to an action of
change where no numerical result has been mentioned. And done so with
a straight face! As if it actually means something!

 

That is true. We get a constant stream of that from
Republicans on a normal basis, and now we're absolutely
being flooded with it.

Perhaps you've been numbed to the degree that you simply
can no longer follow any valid logic? The only thing
is, I don't recall that you've ever been able to, at any
time!

I just gave you an in depth butairly concise description
of how it works, including enough information to abuse
you of several odd notions you seem to want to bring to
the discussion.

Read it again, until you understand it. Every word was
included because it counted. Do not skip through it.

I have no need to rewrite it...

I guess it's just too much for you to understand Tony.

*There is no default white balance.* If you don't think
so, then just try to calculate the color temperture with
a Nikon D4 that is set to use multipliers of 1 for each
channel.

And keep in mind that is exactly what the raw data
recorded in the NEF file is, plus I am in fact using a
preset WB intended to change that as little as possible
(granted that it is off by 4/1000ths, but Nikon lists
two multipliers for 6000K that are different by the same
amount). The green images do not have a "color
temperature", and you can't just crank it up or down.

 

it is true.

nope. it might in some cases, but certainly not always.

sure you can.

it has a list of edits that are applied to the raw which are rendered
on the fly and it caches some of it for speed.

if you make a change to sharpening, for instance, the white balance is
still valid and there's no need to recalculate that. as i said, that
should be obvious but apparently it isn't.

what way is that?

 

that's funny. it's the same as what you said in your response to him,
except your response was full of technobabble about multipliers and
coefficients.

you're arguing just to argue.