calibration -gamma -for colorspace PRophoto?

Monitor: NEC 2690WUXI- DVI

Calibration: eye-one match 3, gammma (2,2= default)

I´ve tried replacing ADOBE RGB with ProHoto RGB with mixed success maybe because-it reguires gamma 1,8?

a) What happens using gamma 2,2 and colorspace Prohoto ?. Does for example black,middletones and white get clipped?

b) Trying to use gamma 1,8 causes problems. The monitor becomes too bright.

Of course I can reduce the brihgtness but then it becomes way under the recommended 120-140

So what to do?
Thanks for any advice

Color-managed applications such as Photoshop will correctly display ProPhoto RGB images. No need to change your monitor gamma. Photoshop will automatically compensate for the difference in gamma.

Your problem may be that you're also viewing images in non color-managed applications. Adobe RGB images will look approximately correct on the NEC 2690 outside of a color-managed app because the 2690's color space is close to Adobe RGB. Similarly, sRGB images look approximately correct when viewed in non color-managed apps on non wide-gamut monitors. In both cases, the images aren't being displayed correctly but they're close enough to make people think they are.

If you want to view images correctly, use color-managed applications.

To be more precise:

I thought:

a) I had to adjust the callibratiion gamma to the colorspace gamma. I was wrong

b) The colorspace gamma for PROFOto is not adjustable (1,8). I´m I wrong her too?

Then finally another thing: I suppose printers- including RIP:S llike Image print can´t handle Prohoto RGB. Conclusion: Before printing convert to ADOBe RGB?

In a color-managed environment, the 1.8 gamma of the ProPhoto RGB color space is not an issue. Color-managed applications will perform the proper color space transformations when displaying on your monitor or printing.

Chose "Image" from the menu bar of the ImagePrint main window and then choose "Color Management". There you can specify the input (ProPhoto RGB) and output (specific to your printer, paper and ink) profiles.

Then finally another thing: I suppose printers- including RIP:S llike Image print can´t handle Prohoto RGB. Conclusion: Before printing convert to ADOBe RGB?

The working color space in your application is ProPhoto RGB, but you need to load a separate ICC specific to your printer and paper (check your printers support/downloads site for ICC profiles). The way I understand it is that your working space color profile is re-interpreted by your printer device color profile so that the print most closely resembles what your screen is showing. If you just pass along the image with the working space ICC, you won't come close (unless you are very lucky - like a broken clock showing the correct time twice a day). And changing the working space to Adobe RGB does nothing for your printer - it really side-steps the whole issue. But using a wide-gamut space like Adobe RGB or ProPhoto works only for images in supporting apps like PhotoShop. Posting to other sites, emailing, etc - where these images will be seen on another PC - should be converted to standard RGB first. If you are working entirely within a supporting environment with printing as the ultimate destination, then the wider gamut spaces make much more sense.

I'm no expert but I just spent several hours trying to work a similar situation out (with some great help, I might add):

http://forums.dpreview.com/forums/readflat.asp?forum=1004&thread=33151448

• • • • leeF

...to email me, click the link on my site below...
http://home.comcast.net/~rodester/

How do I determine the "native gamma" of my (Dell 2209WA) LCD screen?

What is your ballpark guess of gamma for LCD screens?

Hi, Gerry -

You can choose between two (free) programs which allow you to "eyeball" adjust the monitor gamma:

QuickGamma works by modifying the registry settings:
http://quickgamma.de/indexen.html

Adobe Gamma works by creating an ICC profile for the monitor:
http://rapidshare.com/files/76864693/Adobe_Gamma.zip.html

A good discussion of doing this (based mainly on QuickGamma's software, but the general concepts apply to both):
http://www.normankoren.com/makingfineprints1A.html

QuickGamma will actually answer your first question and reveal your pre-adjustment gamma (assume that is what you mean by "native gamma") - but to me at least - that seems rather academic. Both programs will adjust your gamma to the recommended 2.2 from wherever it is sitting now.

I ended up using Adobe Gamma in the end, but I messed around with QuickGamma and it seemed to work as effectively. Keep in mind these are subjective gamma adjustments - read by the eye rather than a calibrator. I'm looking at picking up a Pantone Huey (effective, under $100) at some point to do it "right", but my eyeballing adjustments of gamma, contrast, brightness, and RGB adjustments seem almost dead-on accurate. The Norman Koran link really gives great information on eyeball calibrations - and a great test jpg image to work with.

Good luck!

• • • • leeF

...to email me, click the link on my site below...
http://home.comcast.net/~rodester/