2.2 or 1.8 Gamma on a Mac

Discussion in 'Digital Darkroom' started by lukas_jenkins, May 29, 2006.

  1. I have read that the Mac is gamma 1.8 but should be set to 2.2 to match the Windows world for web sRGB.
    However for inkjet print I wonder if 1.8 is better?

  2. Here's an interesting thread on the subject I stumbled upon on Colorvision's board:

    Personally I think current Macs are all natively close to 2.2 just like PCs. And for that reason they are set to 2.2. The origin of the 1.8 gamma notion is unclear, according to one of the Colorvision's managers. DryCreek claims it's because old monochromatic macs were natively close to it...

    I don't know anything about printer gammas though, so you may have a point there.
  3. Hi Lukas.... when I got serious about digital printing, I calibrated my Mac monitor to gamma 2.2, and also to color temperature 5500K. One good reason to use the 2.2 is that's the gamma of the Adobe RGB file format.
  4. I have my Apple Cinema Display 23" monitor calibrated to gamma 1.8, white point 5500K
    with Gretag-Macbeth Eye One Display 2. The match to the Epson R2400 when printing with
    Photoshop CS2 and a color managed workflow is so good I hardly even think about it
    anymore and only rarely bother with a test print.

    I don't care much about the theory, this setup works great in practical terms.

  5. For any commercial printing and CMYK output even a PC should be set to 1.8 in my experience. For web and desktop printers 2.2 is better. I have 2 profiles stored 1.8 and 2.2 so I can switch between them depending on the work I'm doing. Whatever you choose it has absolutley no relation to your working space gamma.
  6. are you talking about monitor calibration? if so is monitor calibration have nothing to do with
    printer. you calibrated your screen using is native gamma that on all modern screen should
    be around 2.1-2.3, mac or pc. As for the kelvin it should be D65 or 6500K to match as
    possible what you could see under a balanced ligthbox. Gamma 1.8 on a Mac? last time i
    heard or read that was 10 years ago at least...read some good book of color management it
    will help you.
  7. Most of the stuff on the color vision forum was way off.

    Displays have a native gamma (actually a tone response curve but luckily, unlike most
    devices, the curve can be described using a simple gamma formula). There's no such thing
    as a Mac versus a Windows display. The gamma is a physical property of the device.

    The OS on the other hand is different. The Mac has and CONTIUNES to assume a 1.8
    gamma curve response. But the displays native gamma is much closer to 2.2. If you
    calibrate a Mac to a 2.2 gamma, you're doing far less adjustments to the graphic card
    since the display is closer to that behavior. That's a good thing. The downside is on the
    Mac, outside of ICC aware applications that actually look at the profile and see you've
    aimed for a 2.2 gamma, everything looks a bit dark. No big deal. Calibrate your Mac to 2.2
    (better, if your software supports it as the new EyeOne Match does or the older Sony
    Artisan, use Native Gamma). The gamma might be 2.1 so why arbitrarily pick 2.2 when
    that's not correct? Native simply leaves the adjustment alone (like Native White Point does).
  8. So from what I can gather my 20" Apple display, which is currently calibrated to native white
    point and a gamma of 2.2 is correctly calibrated. This also means that from working within
    Photoshop and printing from Photoshop using .icc profiles I am working within a color-
    managed workflow. From what I described colorsync is not applicable if I am correct since
    Photoshop handles color management itself. If everything I just described sounds correct
    then I thank you for your input and clarification.

  9. If your monitor is correctly calibrated (just saying gamma 2.2 and white point = native doesn't mean much), then a color managed print workflow from Photoshop CS2 says:
    Use Print Options
    • set printer with Page Setup
    • Set Photoshop Manages color
    • Set paper profile
    • click print
    • In the printer dialog:
      • set printer settings to advanced and the type of paper, Best photo
      • Set color management settings to NONE
    • That should print as a match to what's on the screen.

  10. Andrew Rodney's response makes a lot of sense for me. The non-colormanaged applications assume 1.8 but since hardware is close to 2.2 then for image quality reasons (8-bit curve adjustments) 2.2 or Native would be better for colormanaged applications. Native still seems a bit too experimental to me - it's gotta be 3 different curves...
  11. Most nonCM apps assume nothing.

    They display RGB data in the image straight to the video card. If
    the gamma adjust to the video card within the profile makes your
    display look brighter, i.e. 1.8 gamma, then 128RGB gray in the
    image will look lighter than setting your monitor profile at 2.2

    The data in the file didn't change. The video gamma correction
    curve within the monitor profile did.
  12. > The origin of the 1.8 gamma notion is unclear

    1.8 was originally used because 1.8 gamma curve was close to the dot gain curve of original LaserWriter, so if you had image looking ok on the screen, it tended to look fine in LaserWriter print as well.
  13. "Most nonCM apps assume nothing."

    OK. Then I don't understand it again.

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