[Mihai]

Unless things have changed recently, It is incorrect to use your calibrated monitor profile in photoshop. you are supposed to use whatever working space profile you are intending (sRBG, Adobe 1998 etc). You are supposed to apply the calibrated monitor profile into your OS' color management settings.

This is where the confusion with this color issue comes into play...the only way we're able to get maxwell renders to look the same in photoshop, as they do in maxwell render, is to apply the calibrated monitor profile in photoshop (which as i've said, is the incorrect way to do it)

Yes, you are right, you shouldn't use the monitors profile in PS. Reading about this, I remember now that PS should first read the embedded profile, then use the systems monitor profile to convert/compensate for the calibration you made, to give you the most accurate colors.

So, IF you've calibrated your monitor, use that as the system profile. If you've set the colorspace to sRGB in Maxwell, and the same in PS - you should get the same display.

Based on this, If you have calibrated your monitor, this is the profile your system is using, if setup correctly. This hich means a maxwell render image would have my color profile embedded in the image...which is incorrect

It's not embedding your system profile, it's embedding whatever colorspace you've specified in Render options. You system profile is for display purposes only, on YOUR monitor.

If you're not seeing the same colors in Maxwell and PS, and you've set the system profile to your calibrated profile, and PS to sRGB (or whatever colorspace you chose in Render options), then something is wrong in the monitor setup or PS. I read there could be bugs if you're using "Enable OGL drawing".

[itsallgoode9]

Thanks for the clarification Mihai, the way you describe it in this post is how my color management workflow looks. I do have Open GL drawing selected, so i'll try it without and see if that makes a difference.

[numerobis]

So if i have my monitor calibrated to sRGB do i have to load this profile in Windows and not in PS? And then switch the PS-Profile to the normal sRGB and not to the
calibration profile? Really?

[itsallgoode9]

So if i have my monitor calibrated to sRGB do i have to load this profile in Windows and not in PS? And then switch the PS-Profile to the normal sRGB and not to the
calibration profile? Really?

Photoshop should not use a calibrated profile. You load your calibrated profile in Windows but use a standard sRGB, Adobe etc profile in photoshop.

[itsallgoode9]

If you're not seeing the same colors in Maxwell and PS, and you've set the system profile to your calibrated profile, and PS to sRGB (or whatever colorspace you chose in Render options), then something is wrong in the monitor setup or PS. I read there could be bugs if you're using "Enable OGL drawing".

I've triple checked and everything is setup correctly. To be honest, maxwell render is the only program i've had this problem with and it only shows it's ugly head when i'm on a computer using a calibrated profile. If i don't use a calibrated profile, things seem to be consistent.

I dunno, any other suggestions or insight?

[feynman]

Justin has a valid point; the perceptual display difference from within Maxwell Render compared to within Photoshop is worrying for anyone used to the regular colour managed workflow. Maybe a recap of the latter will help to find out where the problem lies:

• - Monitors, scanners and cameras use the additive RGB colour space
  - Printing devices use the subtractive CMYK colour space
  - Colour spaces are always device dependent
  - The perceptual CIE-Lab color space, which is device independent, is the all-encompassing reference colour space, defined by the http://www.color.org/
  - Each device should be calibrated and profiled to obtain its input, display or output profile, the ICC profile
  - An ICC profile simply means: "I'm so-so on greens, but my reds put lava to shame". It's a device-quirks-look-up-table, really
  - With device profiles, the CMS, the Colour Management System of Win 7, OSX, Photoshop and others can convert between the colour spaces via CIE-Lab, but not all software has a CMS, though
  - Maxwell Render takes care of gamma by applying inverse gamma internally and reapplies it on writing the final image, so the problem is not with "linear workflow" that plagues other 0.454545-renderers : )

So, one should, that's what I remember learning, go about it like this:

• 1. Calibrate the monitor(s), then profile the monitor(s) - often = ICC display profile for the monitor(s) (colour space quirks of the monitor)
  2. Profile the printer, or obtain printing company's printer profile = ICC output profile for the printer (colour space quirks of the printer, which of course relates only to a certain paper stock and ink set)
  3. Profile the digital camera = ICC input profile for the camera (for cameras outputting RAW, does not work for cameras outputting JPG)
  4. Profile the scanner = ICC input profile for the scanner
  5. Win 7: install all profiles in Color Management / OSX: install all profiles in Color Sync

Then, regarding Photoshop and other colour managed applications, one sets these preferences:

• 1. Working spaces RGB: ProPhoto RGB > Adobe RGB (1998) > sRGB / CMYK: ISO Coated V2 300% (ECI) for us on the continent : )
  2. Color Management Policies RGB: Preserve Embedded Profiles (Why that? So one can work within the profile attached to the image one was given, although one's own setting is different) / CMYK: Preserve Embedded Profiles (Why that? Now you know)
  3. However - under Convert to Profile, one can force an image to acquire a different profile, to convert an Adobe RGB image to a printable CMYK image, for example. This can be simulated via Proof Colors, which is a visual what-if scenario without actually converting (and messing up the image)

Why should one care?

• 1. If one now opens a photo or a scan (in Photoshop), that file's embedded ICC input profile is used by the graphics card, which uses the ICC display profile of the connected monitor, to display the file on the monitor's screen disregarding what one's working space is set to. That's how it should be
  2. If one creates, draws, paints, sketches an image in Illustrator or Photoshop directly, one must attach a profile manually, depending on which colour space one wants to display or print it in
  3. If one wants to print the image, one's own or the printing company's printer's driver, which uses the ICC output profile of the printer, prints the image as one has simulated it with Proof Colors and then, hopefully, converted it to the printer's colour space. If the printer has its own (different) CMS, it must be deactivated to not conflict with Photoshop's CMS
  4. Again: to simulate, how an image will be printed, Photoshop allows on-screen soft proofing with Proof Colors, meaning to preview the image with the desired device's ICC output profile; e.g. for W3C standard (Safari and Firefox are colour managed) or a printing device (inkjet, laser, offset, younameit). It's more than a very good idea to retouch a rendering while soft-proofing is on for the desired display/printing intent
  5. To keep in mind: CIE-Lab > scanner > camera > ProPhoto RGB > Adobe RGB (1998) > fancy inkjet > sRGB > offset printer CMYK > potato printing - the colour space, the gamut, becomes smaller from left to right

Now the issue...

When using Maxwell Render to generate an image, Maxwell Render is the device, just like a camera or a scanner. One renders using Adobe RGB (1998) for the higher gamut compared to sRGB; one can always convert to the lesser colour space later anyways. When the rendering is done, the Maxwell Render device attaches the ICC display profile to our file. Once opened in Photoshop, one can then operate on the image within that colour space and do whatever one fancies. But, alas, the image looks different opened in Photoshop than in Windows 7's slideshow, it looks different viewed in Chrome, it looks different previewed within Maxwell. How can that be? Simple for slideshow, Chrome, Word, and most applications: many applications aren't colour managed, meaning: they ignore a file's embedded ICC display profile and go about displaying images their own unfathomable ways. That's why offset printing from Word documents is not a good idea. Corporate Excel based photo databases? Down the drain with 'em. But what with Maxwell's own image preview and Justin's observation on the very same monitor's screen?

Either, he has Photoshop set to not give a warning when opening files with a different ICC display profile to his Photoshop's Working Space setting and the image is converted upon opening it. Or, Maxwell Render's internal image preview has no proper CMS to display the ICC display profile selected for the rendering, meaning: it does not soft-proof the image properly, so to speak.

?

[feynman]

Hej, anyone from the NL team can maybe reveal, whether the Maxwell Render render preview window is colour managed just as Photoshop is? Then we are closer to know why there is a perceptible difference.

Microsoft humbly says of their Windows 7 "I wish I could give you good news, but the fact of the matter is that the Windows desktop, and most windows components (!) are still not color managed. The Window Photo Gallery, and Windows Live Photo Gallery are the only Windows components that color manage to the display profile. Most Office apps will honor embedded source profiles in images, but then they convert to sRGB and throw that at the display. And IE doesn't even honor embedded profiles in images..."

[tom]

No, it's not color managed. You can see the image in correct colors only if render color space is equal to your system's monitor color space.

[feynman]

Thanks for clarifying! Then it's clear why there's always such a difference. Very good to know, especially when designer colleagues with different computers and different operating systems are collaborating. That means, that it's simply mandatory for everyone to judge renders in Photoshop, not in the preview on the render node or via Remote Desktop.

[itsallgoode9]

No, it's not color managed. You can see the image in correct colors only if render color space is equal to your system's monitor color space.

Curious what the reasoning for Maxwell Render not being color managed? Considering it is used in many industries where color accuracy is important, i'd think that Maxwell would be color managed. Any chance that this will change in future updates?

[tom]

Justin, "it's not color managed" does not mean it's producing an inaccurate/wrong output. It's just the UI working in sRGB and an ongoing challenge with Nokia Qt UI Framework. Of course we're always looking a possible improvement in this area.

[feynman]

+1 for Maxwell Render render preview display being colour managed, allowing to load a desired ICC profile; makes it just that extra bit easier when test-rendering.

[AndreD]

The whole thing seems to be very odd

I just tried to calibrate my monitor with spyder 2 but with no good results.
I´m using a wide garmut monitor that cannot be calibrated by spyder 2 correctly but thats another point

After calibrating, the profile seems to take effect on all applications (inluding mw!) but NOT for MS picture and fax viewer.
(The common picureviewer in win7)
It seems to use the effect "twice" no idea, how to explain it but the calibrated colors are for all appsa the same, even in gimp.
But when I choose "use monitor profile" in gimp, the picture changes and looks exceltly the same like in ms picture viewer.
No I´m wondering, the calibration takes effekt on all apps, I can see it when I use the spyder pofile chooser but what are gimp and ms picviewer doing then?!?

[AndreD]

It wont be correct to use a icc profile within maxwell for displaying the renderview (if it would be possible).
that should be controlled by the operating system.
there is a difference between color space and icc profie.
You can use any color space you want and any icc profile measured for your monitor BUT the measurement has to be done for THE SAME color space that is choosen in maxwell.
(Hope I´m right!)
For spyder2 e.g. sRGB only.
(Makes no sense with a wide garmut screen, by the way. you wont even get a propper sRGB view )

[itsallgoode9]

Hey Andre, most of the basic windows apps don't color manage...MS Picture viewer being one of them. That is showing you an incorrect view of your image, if you have calibrated your monitor. So by applying your calibrated profile to an image in gimp, you are seeing incorrectly still. Gimp is a color managed program, just like Photoshop is, so the correct way to work in gimp, should be to set the working space profile to whatever the inteded color space is (sRGB, Adobe etc). I don't know gimp, so it may be somewhat different. Anyway, here is a link talking about color management in gimp so you can look into it more.

http://docs.gimp.org/en/gimp-pimping.ht ... management