14 Replies Latest reply on Aug 31, 2008 4:01 PM by shooternz

    Zebra level to use for Television and Laptop Targets

      Problem: Zebra level to use for Television and Laptop Targets

      Premiere Pro CS3
      Windows XP SP2

      I created a video which displays great on a large Sony Trinitron television and LCD television. However, when played on a laptop, the image brightness is noticeably less (even at maximum brightness). I assume this is due to the lower luminosity maximum of a laptop screen. I need to create videos (i.e. DVDs) which play both on laptops, CRT televisions, and LCD televisions. The videos are primarily talking heads. What zebra level (100 to 80) should I use while recording which will be bright enough for the laptop but not too bright for CRT and LCD televisions? Thank you in advance for your feedback.
        • 1. Re: Zebra level to use for Television and Laptop Targets
          shooternz Level 6
          The Zebra is not really going to be much help with your issue.

          Zebras are only showing you where in your image the levels (tones) White (100%) and the abitrary grey (65%-85%) are positioned in the scale of 0-100%.

          The issue will always be at the laptop step. Have you checked in a sample of different laptops?
          • 2. Re: Zebra level to use for Television and Laptop Targets
            Level 1
            I assumed this is a common problem and was hoping that someone had published a work flow which would work for the most prevalent laptops.
            • 3. Re: Zebra level to use for Television and Laptop Targets
              Jim_Simon Level 8
              You never adjust your work flow for the display. There is a right way to shoot and edit video, there are correct levels which need to be adhered to. If the display won't show it properly, you either calibrate that display, or use a different one.

              You'll go mad trying to compensate for the millions of variations on improperly calibrated or less than capable displays.
              • 4. Re: Zebra level to use for Television and Laptop Targets
                Level 1
                HP and Toshiba do not publish the brightness specifications for their laptops.

                The Fujitsu N6470 has 370 cd/m2.

                Viewsonic computer and TV LCD monitors are between 400 to 500 cd/m2.

                It appears that laptops have lower maximum brightness than standalone LCD monitors.

                Therefore, one must consider this factor when determining the aperture settings for your camcorder. The goal is to have a compromise which will look reasonable on both a laptop, standalone LCD monitor, and CRT TV which the general public is likely using.
                • 5. Re: Zebra level to use for Television and Laptop Targets
                  Harm Millaard Level 7
                  > The goal is to have a compromise which will look reasonable on both a laptop, standalone LCD monitor, and CRT TV which the general public is likely using.

                  WRONG. The goal is to shoot as accurately as possible. If the monitor you use is not up to the task of displaying the shots correctly, throw it out.
                  • 6. Re: Zebra level to use for Television and Laptop Targets
                    Jim_Simon Level 8
                    >Therefore, one must consider this factor when determining the aperture settings for your camcorder.

                    Oh, God no. Like Harm says, shoot correctly. Trying to compensate for display types during shooting or editing is the wrong way to go. You simply cannot account for all the possible variations, and shouldn't even try.
                    • 7. Re: Zebra level to use for Television and Laptop Targets
                      Level 1
                      For talking head situations, which IRE levels would you recommend for the faces of light complexion speakers. I would use OnLocation to monitor the IRE level and adjust the aperture accordingly.
                      • 8. Re: Zebra level to use for Television and Laptop Targets
                        Harm Millaard Level 7
                        Attach a properly calibrated monitor and adjust aperture accordingly. No sensible IRE settings can be given. Why do you think cameras have viewfinders and external monitors instead of IRE displays?
                        • 9. Re: Zebra level to use for Television and Laptop Targets
                          Jim_Simon Level 8
                          >I would use OnLocation to monitor the IRE level and adjust the aperture accordingly.

                          Sounds like a plan.
                          • 10. Re: Zebra level to use for Television and Laptop Targets
                            shooternz Level 6
                            >I would use OnLocation to monitor the IRE level and adjust the aperture accordingly.

                            Sounds like an arse backwards bad plan to me.

                            Efectively you are over exposing to compensate for a monitor issue and using the iris will have an efect on the black and white levels as well (unless you compensate them with lighting) .

                            Once over (or under exposed) you have lost information in the source image and this makes it difficult to CC or grade.

                            If you need to compensate for the different monitors I suugest you do it in Post with Levels and Gamma Controls from a properly exposed Source clip. Do it differently for each of the Displays (LCD or Laptop)

                            BTW - my laptop displays the material I encode from Broadcast quality material in an entirely satisfactory fashion.
                            • 11. Re: Zebra level to use for Television and Laptop Targets
                              Jim_Simon Level 8
                              >Efectively you are over exposing to compensate for a monitor issue

                              How did you draw that conclusion from the quoted statement? Seems to me the very purpose of OnLocation is to monitor and ensure correct levels.

                              >If you need to compensate for the different monitors I suugest you do it in Post with Levels and Gamma

                              I suggest it not be done at all, and either calibrate the display or use a different one.
                              • 12. Re: Zebra level to use for Television and Laptop Targets
                                shooternz Level 6
                                >How did you draw that conclusion from the quoted statement? Seems to me the very purpose of OnLocation is to monitor and ensure correct levels.

                                My statement was targeted at the OP who obviously was planning to adjust his/her exposures (via the iris control) to an IRE Level to compensate for the "monitor issue". I was advising exactly the same as you.

                                As regards using Post to compensate for various methods of "screening" ...it is sound advice and commonly done. My advice was to do it from correctly exposed material as opposed to compromised material and its no big deal to have multiple versions.
                                • 13. Re: Zebra level to use for Television and Laptop Targets
                                  Jim_Simon Level 8
                                  >My statement was targeted at the OP who obviously was planning to adjust his/her exposures (via the iris control) to an IRE Level to compensate for the "monitor issue".

                                  I'm still confused. How would Petrula use the IRE level to compensate for a deficient monitor? There's no way to correlate the two. I read the statement you responded to as Petrula using OnLocation to read IRE levels in order to make sure they are correct, period, without reference to anything except the correct way to set IRE levels.

                                  >it is sound advice and commonly done.

                                  I have to disagree on both points.
                                  • 14. Re: Zebra level to use for Television and Laptop Targets
                                    shooternz Level 6
                                    Jim - I am not sure what (or why) you are even arguing this.

                                    Below are the quotes from Petrula who plainly was planning to adjust levels by using IRE (ON Location) and his iris. He wants to achieve a compromise exposure when shooting. He intends to up the skin exposure levels to compensate for the laptops. ie lift the exposure. If he really wants a compromise he should do it - open up one stop - but I have yet to see the 'COMPROMISE EXPOSURE SCALE' on any waveform monitor I have used.

                                    >It appears that laptops have lower maximum brightness than standalone LCD monitors.

                                    Therefore, one must consider this factor when determining the aperture settings for your camcorder. The goal is to have a compromise which will look reasonable on both a laptop, standalone LCD monitor, and CRT TV which the general public is likely using.

                                    >For talking head situations, which IRE levels would you recommend for the faces of light complexion speakers. I would use OnLocation to monitor the IRE level and adjust the aperture accordingly.

                                    I use IRE waveform scopes in shooting 90% of my work (which I doubt you do) so I know the value of them but it is "never" that I do not use Post work to sort the images for the intended delivery/purpose.

                                    As regards your doubts about producing different outputs. It may not happen in "Jims Wedding World" but it certainly happens in other sectors.

                                    eg. My colleagues are currently doing three grades on a feature film as we speak. (DVD, Film out and website trailers and also planning a grade for Digital projection). I will point out to you that they are not doing this in their spare bedroom. It is a major facility meeting high end expectations of professionals .