Tweaking monitor calibration

On Mon, 21 Mar 2011 11:07:11 -0800, (Floyd L.
Davidson) wrote:

isw wrote:
I've been trying to get a good color calibration on my 2006 MacBook's
screen; seems to me it was better when it was newer. I think the
fluorescent tube may have aged and changed its color. Things way way too
blue.

Problem is, when the calibrator is invoked, it doesn't start from the
previous settings, it starts from scratch, every time. If the color
errors are subtle, repeated calibrations don't make it "better" they
just wind up "different" -- and still wrong.

I haven't got a clue what kind of software is available
for calibration of a MacBook, nor what kind of a
colorimeter you are using.

I use Argyll software under Linux. It allows
calibrating to different color temperatures, to
different brightness levels, and to different gamma
corrections. There are probably other variations that
I've forgotten are also possible to use, but those are
the ones that I have adjust.

If you want to use a web browser that is not color
managed to view images on the web, your monitor should
be calibrated to gamma 2.2, a temperature of 6500K, and
whatever brightness is appropriate for the ambient
light.

If you want to view images for printing, a calibration
using gamma 2.4 or 2.5 and a temperature from 5000K to
5800K is probably more appropriate, and the brightness
should be down to perhaps 90 cd/m2.

That's interesting. I calibrate my screen to Gamma 2.2 and 6500K using
a Spyder3 (previously a Spyder2 on my old machine).

For my image files I use the Pro Photo RGB color profile which gives
prints on an Epson Pro 3800 printer which are a near perfect match to
what I see on the screen. Color management for printing is done in the
editing software (Nikon NX2) and not in the printer.

What I'd like, is a way to tweak the current calibration, similar to how
you can tweak a photo in GIMP or Photoshop -- just cut a bit of blue in
the highlights, or whatever.

Is there any way of doing that? Any tools that make it possible/easy?

Read the manual for the software you use to calibrate
the monitor with. That shouldn't be hard to do. Color
temperature is what you want to change.

Regards,

Eric Stevens

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

isw wrote:
I've been trying to get a good color calibration on my 2006 MacBook's
screen; seems to me it was better when it was newer. I think the
fluorescent tube may have aged and changed its color. Things way way too
blue.

Problem is, when the calibrator is invoked, it doesn't start from the
previous settings, it starts from scratch, every time. If the color
errors are subtle, repeated calibrations don't make it "better" they
just wind up "different" -- and still wrong.

I haven't got a clue what kind of software is available
for calibration of a MacBook, nor what kind of a
colorimeter you are using.

there is no colorimeter, and if you don't have a clue about what's
available for a mac, why are you even replying?

Because I understand the problem. Which is knowing how
to properly calibrate the monitor.

If the OP has no colorimeter, which means no possiblity
of generating an accurate profile or having a
"calibrated" monitor, that needs to be made clear.

I use Argyll software under Linux. It allows
calibrating to different color temperatures, to
different brightness levels, and to different gamma
corrections. There are probably other variations that
I've forgotten are also possible to use, but those are
the ones that I have adjust.

that's wonderful. the original poster has a mac, not a linux box.

But the point was that the indicated parameters are what
needs to be adjusted, regardless of the OS or the
software used.

If you want to use a web browser that is not color
managed to view images on the web, your monitor should
be calibrated to gamma 2.2, a temperature of 6500K, and
whatever brightness is appropriate for the ambient
light.

mac browsers are colour managed (as is almost everything on a mac),
including the now obsolete microsoft internet explorer from a decade
ago.

"as is almost everything" is the key.

Regardless, the OP does have to have an accurately
calibrated monitor in order to use color management.

If you want to view images for printing, a calibration
using gamma 2.4 or 2.5 and a temperature from 5000K to
5800K is probably more appropriate, and the brightness
should be down to perhaps 90 cd/m2.

gamma should be 2.2 and the white point should be d65 or ideally, the
native white point for the lcd. lower than that is much to warm for
normal purposes, including printing.

Only if you want to look at images posted to the web.

What I'd like, is a way to tweak the current calibration, similar to how
you can tweak a photo in GIMP or Photoshop -- just cut a bit of blue in
the highlights, or whatever.

Is there any way of doing that? Any tools that make it possible/easy?

Read the manual for the software you use to calibrate
the monitor with. That shouldn't be hard to do. Color
temperature is what you want to change.

what he was using is not separate software. it's *part of the system*.

It's software.

it also doesn't work very well since there's no hardware puck.

I'd expect that to be true; but the OP did not clarify
that point, and therefore my response was generic to
either with or without the proper hardware and with a
obvious hint that the proper hardware absolutely is
necessary.

Whatever, your post was not helpful, had absolutely no
value to anyone, and followups that are the same will
be ignored.

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

Eric Stevens wrote:
On Mon, 21 Mar 2011 11:07:11 -0800, (Floyd L.
Davidson) wrote:

If you want to view images for printing, a calibration
using gamma 2.4 or 2.5 and a temperature from 5000K to
5800K is probably more appropriate, and the brightness
should be down to perhaps 90 cd/m2.

That's interesting. I calibrate my screen to Gamma 2.2 and 6500K using
a Spyder3 (previously a Spyder2 on my old machine).

For my image files I use the Pro Photo RGB color profile which gives
prints on an Epson Pro 3800 printer which are a near perfect match to
what I see on the screen. Color management for printing is done in the
editing software (Nikon NX2) and not in the printer.

Color managed software will adjust it.

But for example, if you use a web browser that is not
color managed, what you see will not be what you'd get
from a print. Many other ways to view images are also
not color managed...

Your statement that "management for printing" is not
done in the printer is a key that is often missed. The
point is never to adjust the print to look like the
screen, but rather is to make the screen show what the
print will be.

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

On Mon, 21 Mar 2011 14:16:59 -0500, nospam wrote:

In article , Better Info
wrote:

to properly calibrate a display, you need a hardware colour puck. they
range in cost from under $100 on up. trying to do it visually is a
guessing game and never works properly because the eye is not very
precise.

Correction: MOST people's eyes are not very precise.

everyone's eyes. it's physiology.

One friend's mother
would amaze me with her ability to perceive, and even more uncannily,
remember colors accurately. She could go into a fabric-store and notice a
color she wanted, but the price would be too high. Then a week later notice
the same color in another store made by some other company, and buy it
because it was at a good price. When taking a swatch back to the first
store they'd be identical.

bull****.

NOPE!

Take this test: http://www.xrite.com/custom_page.aspx?PageID=77

Then report back, being honest (can you do that?).

rOn Mon, 21 Mar 2011 10:11:45 -0700, isw wrote:

I've been trying to get a good color calibration on my 2006 MacBook's
screen; seems to me it was better when it was newer. I think the
fluorescent tube may have aged and changed its color. Things way way too
blue.

Problem is, when the calibrator is invoked, it doesn't start from the
previous settings, it starts from scratch, every time. If the color
errors are subtle, repeated calibrations don't make it "better" they
just wind up "different" -- and still wrong.

What I'd like, is a way to tweak the current calibration, similar to how
you can tweak a photo in GIMP or Photoshop -- just cut a bit of blue in
the highlights, or whatever.

Is there any way of doing that? Any tools that make it possible/easy?


I doubt that you will be able to solve your problem by manual
adjustment using the Mk 1 eyeball. For accuracy and sensitivity you
will need a calibration device of some kind.

I use the Spyder 3. See http://spyder.datacolor.com/products.php for
the product range. You may be able to buy more cheaply from Amazon or
B&H etc. You may still find that the errors in your screen have
drifted so far that that simple calibration is not possible.

Have you considered replacing the fluorescent tube? That might not be
particularly expensive, although Apple would rather sell you a new
screen.

Regards,

Eric Stevens

On Mon, 21 Mar 2011 15:22:58 -0500, Better Info
wrote:

On Mon, 21 Mar 2011 12:35:25 -0500, nospam wrote:


gamma should be 2.2 and the white point should be d65 or ideally, the
native white point for the lcd. lower than that is much to warm for
normal purposes, including printing.

Mac platforms are at gamma 1.7, or used to be.

http://support.apple.com/kb/ht3712

"To better serve the needs of consumers and digital content
producers, Mac OS X v10.6 Snow Leopard uses a gamma value of 2.2
by default. In versions of Mac OS X prior to 10.6, the default
system gamma value was 1.8. Using the capabilities of ColorSync,
the gamma value of 2.2 is automatically applied and seamlessly
transitions your display, images and videos to the new gamma
value. If you are a graphic or video professional, read below for
more information.

Regards,

Eric Stevens

On Mon, 21 Mar 2011 16:52:25 -0500, Better Info wrote:

On Mon, 21 Mar 2011 14:16:59 -0500, nospam wrote:

In article , Better Info
wrote:

to properly calibrate a display, you need a hardware colour puck. they
range in cost from under $100 on up. trying to do it visually is a
guessing game and never works properly because the eye is not very
precise.

Correction: MOST people's eyes are not very precise.

everyone's eyes. it's physiology.

One friend's mother
would amaze me with her ability to perceive, and even more uncannily,
remember colors accurately. She could go into a fabric-store and notice a
color she wanted, but the price would be too high. Then a week later notice
the same color in another store made by some other company, and buy it
because it was at a good price. When taking a swatch back to the first
store they'd be identical.

bull****.

NOPE!

Take this test: http://www.xrite.com/custom_page.aspx?PageID=77

Then report back, being honest (can you do that?).

Just did it again, as a test for this monitor I'm using more than any test
for my eyes. A couple years I got a perfect score the first time using a
good monitor. I'm now using an old CRT backup monitor for surfing. It's
greatly lost its contrast and BV range. I was curious as to how well it was
representing the spectrum to me.

Here's what I got this time on my first try using this old monitor:

"Online ColorIQ Challenge Results
You have perfect color vision!
FM Hue Test Results .... "

I guess this monitor is okay for surfing after all.

On Mon, 21 Mar 2011 16:52:25 -0500, Better Info wrote:

On Mon, 21 Mar 2011 14:16:59 -0500, nospam wrote:

In article , Better Info
wrote:

to properly calibrate a display, you need a hardware colour puck. they
range in cost from under $100 on up. trying to do it visually is a
guessing game and never works properly because the eye is not very
precise.

Correction: MOST people's eyes are not very precise.

everyone's eyes. it's physiology.

One friend's mother
would amaze me with her ability to perceive, and even more uncannily,
remember colors accurately. She could go into a fabric-store and notice a
color she wanted, but the price would be too high. Then a week later notice
the same color in another store made by some other company, and buy it
because it was at a good price. When taking a swatch back to the first
store they'd be identical.

bull****.

NOPE!

Take this test: http://www.xrite.com/custom_page.aspx?PageID=77

Then report back, being honest (can you do that?).

Just did it again, as a test for this monitor I'm using more than any test
for my eyes. A couple years ago I got a perfect score the first time using
a good monitor. I'm now using an old CRT backup monitor for surfing. It's
greatly lost its contrast and BV range. I was curious as to how well it was
representing the spectrum to me.

Here's what I got this time on my first try using this old monitor:

"Online ColorIQ Challenge Results
You have perfect color vision!
FM Hue Test Results .... "

I guess this monitor is okay for surfing after all.

In article , Floyd L. Davidson
wrote:

I've been trying to get a good color calibration on my 2006 MacBook's
screen; seems to me it was better when it was newer. I think the
fluorescent tube may have aged and changed its color. Things way way too
blue.

Problem is, when the calibrator is invoked, it doesn't start from the
previous settings, it starts from scratch, every time. If the color
errors are subtle, repeated calibrations don't make it "better" they
just wind up "different" -- and still wrong.

I haven't got a clue what kind of software is available
for calibration of a MacBook, nor what kind of a
colorimeter you are using.

there is no colorimeter, and if you don't have a clue about what's
available for a mac, why are you even replying?

Because I understand the problem. Which is knowing how
to properly calibrate the monitor.

i also understand the problem, and unlike you, i am very familiar with
how it's done on a mac and what's available.

If the OP has no colorimeter, which means no possiblity
of generating an accurate profile or having a
"calibrated" monitor, that needs to be made clear.

it was very clear to someone who is familiar with macs.

If you want to use a web browser that is not color
managed to view images on the web, your monitor should
be calibrated to gamma 2.2, a temperature of 6500K, and
whatever brightness is appropriate for the ambient
light.

mac browsers are colour managed (as is almost everything on a mac),
including the now obsolete microsoft internet explorer from a decade
ago.

"as is almost everything" is the key.

the key for what? on a mac, colour management is part of the operating
system, not an afterthought.

Regardless, the OP does have to have an accurately
calibrated monitor in order to use color management.

yes, that's true and it's not going to happen by eyeballing it, but he
really just wants his images to not be too blue. i doubt he's doing
colour critical work, or even cares about colour management at all.

If you want to view images for printing, a calibration
using gamma 2.4 or 2.5 and a temperature from 5000K to
5800K is probably more appropriate, and the brightness
should be down to perhaps 90 cd/m2.

gamma should be 2.2 and the white point should be d65 or ideally, the
native white point for the lcd. lower than that is much to warm for
normal purposes, including printing.

Only if you want to look at images posted to the web.

nope. that's the best setting for a display for both printing and
looking at images.

What I'd like, is a way to tweak the current calibration, similar to how
you can tweak a photo in GIMP or Photoshop -- just cut a bit of blue in
the highlights, or whatever.

Is there any way of doing that? Any tools that make it possible/easy?

Read the manual for the software you use to calibrate
the monitor with. That shouldn't be hard to do. Color
temperature is what you want to change.

what he was using is not separate software. it's *part of the system*.

It's software.

everything is software. there you go trying to weasel out of it. what
he used is part of the operating system itself. there's nothing to
install and there is no manual specifically for it. there's not much to
it either, it's fairly self explanatory, which if you had a clue about
macs (your words), you would know.

it also doesn't work very well since there's no hardware puck.

I'd expect that to be true; but the OP did not clarify
that point,

as i said, it was clear from his description, as anyone who has done it
on a mac would know.

and therefore my response was generic to
either with or without the proper hardware and with a
obvious hint that the proper hardware absolutely is
necessary.

you said you 'haven't got a clue what kind of software is available for
calibration of a MacBook, nor what kind of a colorimeter you are
using,' so there really isn't much help you can offer, is there?

Whatever, your post was not helpful, had absolutely no
value to anyone, and followups that are the same will
be ignored.

neither was yours.

In article , Floyd L. Davidson
wrote:

If you want to view images for printing, a calibration
using gamma 2.4 or 2.5 and a temperature from 5000K to
5800K is probably more appropriate, and the brightness
should be down to perhaps 90 cd/m2.

That's interesting. I calibrate my screen to Gamma 2.2 and 6500K using
a Spyder3 (previously a Spyder2 on my old machine).

For my image files I use the Pro Photo RGB color profile which gives
prints on an Epson Pro 3800 printer which are a near perfect match to
what I see on the screen. Color management for printing is done in the
editing software (Nikon NX2) and not in the printer.

Color managed software will adjust it.

But for example, if you use a web browser that is not
color managed, what you see will not be what you'd get
from a print.

that depends what software is used to print it. just because a browser
is not colour managed doesn't mean the printing software isn't.

Many other ways to view images are also
not color managed...

actually not that many.

Your statement that "management for printing" is not
done in the printer is a key that is often missed.

the key is to not do it twice.

there's nothing inherently wrong with doing it in the printer, but if
so, it must not also be done on the computer. pick one or the other,
not both.

The point is never to adjust the print to look like the
screen, but rather is to make the screen show what the
print will be.

that part is true.