18 Replies Latest reply on Apr 15, 2008 3:18 PM by Michael Tissington

    Confused ... luminance ?

    Michael Tissington
      I have an NEC 2690 monitor and calibrated it with SpectraView.
      I've had my paper calibrated and I'm using an Epson 3800.
      I'm certain I have my workflow correct, letting PS manage color and switched
      it off in the Epson printer driver.

      The problem is when I print anything, it always appear to be much darker
      than what I see on the screen.

      Is this something to do with what I have the luminance set to ?

      I've read that some people set it to between 85-90 ... how do I know what is
      correct ?

      Thanks.
        • 1. Re: Confused ... luminance ?
          (Marco_Ugolini) Level 1
          A few questions:

          1) How do you view the prints that you are judging to be too dark? Do you use a color-correct viewing booth? If so, is it placed close to your monitor, in a dimly-lit environment?

          2) During your monitor calibration, do you match the luminance and white point of your monitor to that of the viewing booth?
          • 2. Re: Confused ... luminance ?
            Lou Dina Level 3
            Michael,

            85-90 cd/m2 is a great starting point for monitor white luminance. As Marco is suggesting, your ambient lighting, final viewing environment and inspection booth lighting also factor in. Many people make the mistake of setting their monitor luminance too high, and then their prints look very dark and muddy in comparison.

            The whole key is to calibrate monitor brightness to be in synch with your usual viewing and display lighting. It's a "system" and all the parts have to work together.

            FWIW, I calibrate my monitor to 90cd/m2. I find that this works well for my overall system. A pure white document in Photoshop should have the same apparent brightness as a sheet of white paper displayed under your normal viewing lights. And you viewing lights should be within a reasonable brightness level compared to normal viewing conditions.

            Lou
            • 3. Re: Confused ... luminance ?
              Michael Tissington Level 1
              The viewing conditions are not controlled so my answer to both of these is
              No.
              This is for fine art print that people will hang in their living room.
              • 4. Re: Confused ... luminance ?
                Michael Tissington Level 1
                Lou,

                Thanks ... I'm beginning to get the complete picture ... can I measure the
                luminance of a generic living room ?

                And then there is the question of which color temperature to use too ... ??
                • 5. Re: Confused ... luminance ?
                  Lou Dina Level 3
                  Michael,

                  Yes, you can measure the light levels in your living room if you have a spectrophotometer with a light gathering head (and i1 will work) and the right software. Gretag (now Xrite) has a free software download for called EyeOne Share that can read ambient light levels.

                  Having said that, light levels and temperatures will vary all over the board, but you can bet they are usually low levels. And the color temp will usually be warmer than 6500K, except on those cloudy bright days where you have all room lights off and have plenty of outdoor light spilling into the room.

                  If you want to learn more, read the article on Monitor and Printer profiling on my website:

                  http://www.dinagraphics.com/color_management.php

                  It discusses coordinating monitor luminance, viewing lights and final display.

                  I'd recommend starting with monitor calibration parameters of 85-90 cd/m2 luminance, 2.2 gamma, and a white color temp between 5000-5500K. The article explains my position. I think you will find these parameters give you excellent results.

                  Lou
                  • 6. Re: Confused ... luminance ?
                    genenphotos
                    >If you want to learn more, read the article on Monitor and Printer profiling on my website:

                    http://www.dinagraphics.com/color_management.php

                    Lou, I'm glad I found your site but I don't see any articles there. I must be missing something.

                    --Gene
                    • 7. Re: Confused ... luminance ?
                      Lou Dina Level 3
                      Gene,

                      Go do http://www.DinaGraphics.com. Click the Color Management menu at the top of the page. On the left side, you will 3 selections, Introduction, Monitor & Printer Profiling, and Profiling Targets.

                      Pick the Monitor & Printer Profiling link. After clicking this link, you will see a link to download the PDF file in the text box to the right.

                      There are downloads in the Intro and Targets sections too. If you are relatively new to color management, I'd also suggest reading the Intro article.

                      Lou
                      • 8. Re: Confused ... luminance ?
                        Michael Tissington Level 1
                        Lou,

                        Thanks for this - come to Port Townsend, WA and I'll buy you lunch :)

                        Michael
                        • 9. Re: Confused ... luminance ?
                          Lou Dina Level 3
                          Michael,

                          You're welcome....and I may take you up on lunch. I have a brother in Bothell and a daughter living in Graham, so I get out to the Seattle area at least once a year.

                          Lou
                          • 10. Re: Confused ... luminance ?
                            (Andrew_Rodney) Level 1
                            The 2690 is going to be hard pressed to get anywhere near 90-95cd/m2! I started at 120, my sources inside of NEC suggested 150 as a minimum for a newer unit.
                            • 11. Re: Confused ... luminance ?
                              Michael Tissington Level 1
                              I have a new NEC 2690 and it easily calibrates at 85, I'm actually have it
                              calibrated at 90 and my pictures now match great :)
                              • 12. Re: Confused ... luminance ?
                                (Andrew_Rodney) Level 1
                                >I have a new NEC 2690 and it easily calibrates at 85, I'm actually have it
                                calibrated at 90 and my pictures now match great

                                You can do it, its just not recommended (I suspect because its a big adjustment to the LUT, albeit in the display in high bit). IOW, you're not physically altering the backlight to that level cause its not going to go that low.
                                • 13. Re: Confused ... luminance ?
                                  (Marco_Ugolini) Level 1
                                  Is it necessary to go that low anyway? Meaning, is there a *need* to go that low to match the luminance of a light booth placed next to the display?

                                  It doesn't seem to be the case here, since, in Michael's own words, "the viewing conditions are not controlled [...] This is for fine art print that people will hang in their living room."

                                  On the other hand, Michael also says that he has "a new NEC 2690 and it easily calibrates at 85, I'm actually have it calibrated at 90 and my pictures now match great." I'm not clear which viewing conditions the image on the display "matches great" to, since those conditions are admittedly "not controlled."
                                  • 14. Re: Confused ... luminance ?
                                    Michael Tissington Level 1
                                    I'm not using a light booth ... I'm talking about creating prints that are
                                    going to be viewed in the 'average' living room without any dedicated
                                    lighting on them.

                                    Yes there is a *need*, without being calibrated down to 90, ALL my prints
                                    were too dark, now I can adjust them in Photoshop and be fairly confident
                                    they will look good in print.

                                    Why would I want to use a light booth when the end viewing conditions are
                                    not controlled ?
                                    • 15. Re: Confused ... luminance ?
                                      (Andrew_Rodney) Level 1
                                      >Is it necessary to go that low anyway? Meaning, is there a *need* to go that low to match the luminance of a light booth placed next to the display?

                                      What I do is set the display luminance for my viewing box (which has its own controls as well). So getting the NEC to 150cd/m2 isn't an issue as I can raise the luminance quite easily on the light box to make a screen to print match (in terms of luminance).

                                      IF you're not doing this, you're viewing prints somewhere else, you don't need to view the display and then the print, there's no reason to dial the display down so low, especially when that luminance is artificially being set.

                                      >I'm talking about creating prints that are
                                      going to be viewed in the 'average' living room without any dedicated
                                      lighting on them.

                                      Tell me what the luminance in terms of candela per meter squared is the "average" living room. IOW, its got nothing to do with the conditions of the display.

                                      >Why would I want to use a light booth when the end viewing conditions are
                                      not controlled ?

                                      A light booth IS a controlled lighting condition.
                                      • 16. Re: Confused ... luminance ?
                                        Lou Dina Level 3
                                        Michael,

                                        Your current settings are probably pretty close, especially for what you are doing. To me, the sensible thing here is to work backwards.

                                        First, establish the typical environment and lighting level where you will view most of your prints (which you have done). Then, you step back to your viewing booth, viewing lights, or whatever you use to compare your prints to the monitor. Those viewing lights shouldn't be orders of magnitude brighter or darker than the lighting where you will view your framed and mounted prints. Then, lastly, select a monitor luminance so a pure white document in PS on the monitor is reasonably close to your white paper under your viewing lights.

                                        Of course, if you view your prints under dedicated museum lights, in a very bright room, outdoors, etc, this would probably justify a brighter viewing booth and higher monitor luminance. But if you viewing booth and monitor luminance are a LOT brighter than your final display lighting, your prints will always look dark and muddy.

                                        Frankly, most people who complain of dark, muddy prints have their monitors cranked up way too bright. All three (final display, viewing booth, monitor luminance) have to be reasonably close if you want a good match. I have always found about 90 cd/m2 to be good, not only for prints I hang in my home, but also for proofs on jobs going to press. Use what works, and let your eyes be the judge.

                                        Lou
                                        • 17. Re: Confused ... luminance ?
                                          (Marco_Ugolini) Level 1
                                          >I'm not using a light booth.

                                          Yes, I understand that. I acknowledged that much in my reply.

                                          >Why would I want to use a light booth when the end viewing conditions are not controlled ?

                                          You said that things "match great" to what you admit is an uncontrolled viewing environment. I fail to understand how that "match" can be assessed.
                                          • 18. Re: Confused ... luminance ?
                                            Michael Tissington Level 1
                                            Guys, thanks for your help - until I asked my question I did not realize
                                            that luminance played such a critical role in my workflow ... I'm happy with
                                            the results I get at 90 however when I start having my prints on display in
                                            galleries I'll obviously have to rethink my environment.