Gamma setting

After seeing numerous comments on my photos about "subtle" colors

and "not overly saturated" etc I came to the conclusion what I'm

seeing and what they're seeing are two different things. I've just

discovered this is due to the gamma setting in Paint Shop Pro and

Photoshop 7 - I'd always thought PS7 showed the photos WAY too

light - and Painthop was just about right. Gamma for PSP is set at

1, and PS7 is set at 1.8. I did some reading and saw that PCs are

set to a default of 2.2.

 

What on earth do I set the gamma as in PS7, PSP and/or my monitor? I

know there's a calibration thing to be done with the monitor but a

couple hundred bucks for the hardware is out of the question. I've

tried using the charts, but get nowhere. The very best I can get is

with brightness and contrast set at 100% for both... and I have no

idea if there's a "gamma" setting or if that's controlled by

brightness/contrast.

 

HELP!

Oh, I should probably mention I have an LCD flat panel 1800FP(Analog) monitor from Dell, and the gamma setting on it (after a long search!) is .95

The standard monitor gamma on a Mac is 1.8. Your monitor should be set to that value as

well. However, when calibrating your monitor, gamma 2.2 is mostly recommended for the

sake of standardising over different systems. (Prepress workers generally are using 1.8,

photographers use 2.2) On my Mac system I am using a Mac Cinema Display (an LCD)

which is calibrated to a gamma of 2.2. Photoshop will correctly convert your used color

space to what you see on your monitor because it will use the info from your monitor

profile for the translation. So either set your monitor to gamma 1.8 or 2.2 and tell that to

Photoshop.

<I>The standard monitor gamma on a Mac is 1.8. Your monitor should be set to that

value as well. </I>That isn't really true anymore. Use a monitor gamma setting of 2.2

I use Nvidia GeForce4 MX 420 - and when I set the gamma to 2.2 it all but whites out everything. There's no possible way that view is normal. I turned brightness down to 10 (of 100) and contrast at 86 before it approached anything I could possibly look at for more than 5 minutes. Absolutely everything was washed out! So I tried 1.8 which was only moderately better. I've got it on 1.0 at the moment and that's about as bright as I can stand it - though I can see each block on those black-white scales which I couldn't before, so is that progress? I don't get this at all...

Since you are running PSP, you must be using a Windows system, in which case are you using Adobe Gamma (from the Control Panel) to do a basic monitor calibration? You can set the gamma to 2.2 in that. A monitor profile will be created and loaded on system boot by Adobe Gamma Loader. The monitot adjustment is then system wide, not just for Photoshop. You can check the gamma setting with the tool at:

 

http://www.cs.berkeley.edu/~efros/java/gamma/gamma.html

 

John

<A HREF="http://www.normankoren.com/color_management_2A.html">THIS</A> page has a visual test for gamma settings as well as an explanation of the gamma setting.

The Norman Koren chart linked above is one of the most correct gamma charts available as far as I can determine. Personally I never got along all that well with Adobe Gamma, I recommend WiziWYG instead for free visual calibration.

Hello Kathy<p>

your use of the graphics card configuration to adjust your monitor gama needs a little clarification. The value shown in the configuration is not an absolute value like 2.2 or 1.8, it is the extent of the change that is to be made with a value of 1 indicating no chnage. So setting this value to 2.2 will give the results you saw.<p>

It is possible to get reasonable results without hardware calibration, look at the link below for detailed step by step instructions.<p>

<a href="http://www.photo-i.co.uk/BB/viewtopic.php?t=183">monitor calibration without hardware</a><br>.

Thank you all! :) Gary and Steven's option worked out best for me, though I think my eyes have gone crazy from those charts! After a while I didn't know if I was seeing things or not :) But I believe I now have the thing set right, and it wasn't as huge a change as I thought it would be, though the effect on my photos is rather dramatic considering I thought they were so much darker/saturated than they are. This is going to take a little getting used to.

-->The standard monitor gamma on a Mac is 1.8. Your monitor should be set to that

value as well. However, when calibrating your monitor, gamma 2.2 is mostly

recommended for the sake of standardising over different systems.

 

Its a bit more complicated than that.

 

Displays have a native Tone Response Curve (TRC) specified by a gamma value, which is a

result of their natural behavior. Gamma is a specific formula (output = input gamma ) that

describes a very simple curve. This curve, the result of this gamma formula, in the case of

a display, describes input amplitude (voltage) and the corresponding light output

(brightness). Various values for gamma produce different curves. So we can use a single

number to describe this type of curve. However, many devices do not follow this formula,

their curves are far more complex and are not gamma curves nor should we use gamma to

describe them (tone response curve is the accurate term).

 

There is no difference between a display a user will connect to a Macintosh versus a

Windows system. The operating system does make some assumptions about gamma. The

TRC gamma assumed by the Macintosh is 1.8 while the TRC gamma assumed by the

Windows operating system is 2.2. Over the years, most Macintosh users were under the

impression that the correct TRC gamma to use as a target value was 1.8. This is due to the

early Macintosh operating system attempting to produce a screen to print match on

devices that also used a TRC gamma of 1.8; the LaserWriter printer. Since color

management didn?t exist back in those days, producing a native TRC gamma of 1.8

assured that the Grayscale output and the preview of images on the Macintosh were

closer. However, the display?s native TRC gamma was not close to this gamma

assumption. The native TRC gamma of most displays is in the neighborhood of 2.0 to 2.2.

Today the use of 1.8 gamma within the Macintosh OS is simply a legacy and not useful. If

a user calibrates the display to something other than a TRC of gamma 1.8, the appearance

of color outside ICC-aware applications will appear darker or lighter. There are compelling

advantages to calibrating a display as close to the native, physical TRC gamma as possible.

The farther the display calibration is from the native gamma of the display, the more

adjustments have to be produced at the graphic card. Macintosh users should set their

TRC gamma target value to 2.2 instead of 1.8. The slight darkening of images outside ICC

aware applications is not severe enough to present a problem and the results of keeping

the display calibration closer to it?s native condition is less aliasing of images.

 

Since TRC of the display set for calibration is recorded in the ICC profile and this

information is provided to Photoshop and other ICC-aware applications images outside an

ICC aware application like Photoshop may appear a bit dark. However the soft proofing

previews in Photoshop are correct. This is how a Macintosh user and a Windows user can

view the same image with the same color appearance even if both systems are assuming a

different gamma.

 

The natural TRC of an LCD is a severe S curve and doesn?t even remotely follow the

gamma formula. LCD manufacturers want to have their displays act like CRTs. End users

who don?t use color management expect the colors to be at least ?in the ball park? of what

they are used to seeing on CRTs. To achieve this, the LCD has a built-in 8-bit LUT (Look-

Up Table), which makes the LCD follow the gamma formula, usually gamma 2.2. By

converting 8-bit input data into 8-bit output data, the result is banding (aliasing) in

images.

Good God.

 

So is my monitor too bright now, or what? I'm having a hard time getting used to it...it just seems wrong somehow, but I want my pictures to present as I see them - I know that's not completely possible because it seems everyone on the planet has a different setting on their monitor, but shouldn't it at least be close? When I print these pictures (from any application) they are only *very slightly* lighter than what they look like on my screen. I'd thought this meant stuff on my side was "correct" - but then it just seemed like no one saw it the same. And so maybe I wasn't seeing other photographer's work as it was supposed to be.... like all those pictures I thought were too dark.

-->So is my monitor too bright now, or what?

 

Brightness (luminance) has NOTHING to do with Gamma. Your profiling software with

instrument will ask for a target value for luminance (specified in cd/m2). This is based on the

ambient light around the display. For an LCD, try a setting of 120 cd/m2 or 95 cd/m2 for a

CRT (assuming in the later case a pretty low ambient light of about 20 LUX).

 

Andrew Rodney

www.digitaldog.net

The exact gamma setting is not too important. What is important is that you should be able to see at least 7 (preferably 8 or 9) equally spaced grey-scale bars on you monitor once calibrated. This should allow you to view 90% of the images on the web. Example: http://www.capetownskies.com/grey_scale.gif

The exact TRC gamma setting for a display is not all that important unless your goal is to

produce the least amount of aliasing in image previews. The best gamma is the native

gamma but only one product I know of, now discontinued (Sony Artisan) can actually target

for that native TRC gamma for each individual display.