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AF101 PAL color bars - How do I calibrate my external monitor?

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    AF101 PAL color bars - How do I calibrate my external monitor?

    Hi all,

    I apologise in advance if this question has been answered elsewhere. I've searched and searched and still can't find a satisfactory, step-by-step answer to my question. Hope you can help.

    I'm using an Af100 (Af101) in PAL land with a 7" SWIT S-1071F external monitor. The camera outputs PAL color bars to the monitor which are not the same as NTSC color bars, so the process for calibrating is different to the NTSC process described in such detail across the web. I have found some PAL guidance online, which in general outlines a "turn down everything, turn up brightness, turn up contrast, turn up color" process that I think may work well for professionals with a keen eye for what looks right but which seems a bit generalised and hit-and-miss for newbies like myself.


    If I wanted to calibrate my monitor using the color bars generated by my Af101, what would be the best step-by-step (dare I say, fool-proof) process you would recommend for getting a color accurate monitor?

    Any advice would be much appreciated.

    #2
    The UK/Euro AF101 doesn't display a Pluge bar set - I'm guessing you're talking about using those to set up contrast etc. In my experience, it'll give you a basic starting setup from which to tweak by eye - but will it really give you confidence in what's being recorded? There are so many variables at play, including ambient light and, having played around with various cheaper options, I've reluctantly had to accept that monitors, like microphones, lighting and tripods, can't be scrimped on - they're out of kilter with the whole DSLR/Prosumer revolution that says you can have it good and cheap.

    FWIW, unless you're spending at least 1000 on a monitor at the moment, I think any amount of calibration is going to be fairly crude and might only show you something in the ballpark of what's being recorded. In the UK and Ireland (ie what's imported officially and supported over here), I think your best starting point at the moment is something like a TV Logic 056W, which will need minmal tweaking before you're confident.

    If you can't afford that at the moment, you could try calibrating to bars by outputting an HD bars pattern from FCP 6 or 7 and run the desktop preview output through HDMI. After that, try and create a controlled environment with unchanging light levels and temperature, film a reasonable quality colour reference chart and compare what you're seeing on the SWIT with the final monitor that you're trusting (eg an Apple screen, which is a pretty good quality reference.) Tweak from there and also check skin tones - those are the colours that will particularly trip you up in post if your monitor is wrong.

    Oh, and white balance - I really recommend the Lastolite pop up grey card for reliable white balancing - the AF101's Achille's Heel, in my opinion. Be scrupulous about that, don't use cheap LED or Fluoro lights and you can worry less about whether your monitor is colour accurate and rely on it more for critical focus and composition etc. The waveform monitor and zebras will tell you much more about exposure.

    Ben.
    Ben Giles BFE BAFTA

    www.matobo.co.uk

    @MatoboLtd

    Comment


      #3
      Thanks so much for the advice, Ben. It's really helpful and I'm very grateful to you for taking the time to respond. I totally agree it is not advisable to go cheap on a monitor if funds permit. In defense of my little Swit monitor, I researched the options a lot prior to purchasing the (slightly) higher end Swit monitor I did. Reviews compared the model very favorably to the TV logic you recommend and, funnily enough, it did cost me over a grand at the time - ouch! It's working well for me so I have no complaints. It is capable of being tweaked to calibrate it to an extent, hence I was wondering about the procedure.

      I say tweaked because from what you're telling me, any tweaking to my monitor is likely to only get me in the ballpark in terms of color accuracy. I can live with that. Would I therefore be correct in saying that most of these smaller external monitors are generally not capable of being calibrated to achieve a comparable kind of color accuracy you would get on a properly set-up studio monitor? Also, I 100% take on-board your input regarding the other factors which come into play, such as ambient light. And white balance. In terms of the latter, I'm using the Vortex Media warm card white balance system and find it works well.

      So, if I forget about calibrating my Swit monitor in the strict sense and talk instead of tweaking it to get it into a state of ballpark color accuracy, what is the best method? Should I forget about outputting color bars from my Af101 and instead output bars from FCP7 and tweak and compare as you outline in your response above? And when using a color reference chart as you outline, I'm guessing it's just a matter of trial and error in terms of what levels I tweak (or is there a particular order to what levels to tackle first...?).

      In my original post, I made reference to other guidance I'd come across on this topic. I'm wondering if it might be helpful to ask for opinions on this method, though it might be dated now and refer to an SD rather than HD world:

      I have used these mixed but common methods of setting up PAL monitors for years.
      Choose the EBU 100% standard “PAL full-frame bars” from FCP
      Turn color, contrast and brightness all the way down.
      Turn up brightness until you see the black bar just start to light up.
      Turn up contrast until the bars display an even grayscale – not including the 100% white bar. This bar should not be glowing (turn up until the white bar doesn’t get brighter then pull back a bit).
      Turn up color until the red bar is fully red but not glowing. On monitors with “blue-only” the 3 bars to the right should be equal shades of blue.
      Test and maybe fine-tune using a real picture you know has full color information and dynamics. This means good saturation, blacks, whites, low and high mid-tones.
      The full article is available here: http://www.larryjordan.biz/calibrati...video-monitor/

      I also recall watching an instructional video on lighting presented by Eric Huyton, which contained a section on tweaking his external monitor on set using PAL color bars outputted from his camera (again, I'm guessing in an SD world rather than HD). This might be relevant too if anyone has seen it.

      Sorry for pursuing this subject to death, but I'm just trying to learn and this issue keeps coming up for me. I play the guitar as well, and I'm a pain in the ass about being in proper tune too...

      Thanks so much again,
      James

      Comment


        #4
        if i recall correct you switch your af100 to ntsc to get ntsc color bars to use for calibrating monitor

        Comment


          #5
          Hi James.

          Yes, I've used that method in the past for PAL CRT monitors - the combination of bars and blue-only would usually get you results that were consistent with other monitors. I guess my point is that the overall quality of the driver, panel and factory calibration of an LCD field monitor are probably the most important factors.

          At the end of the day, you just want to know that what you're seeing in the monitor is near as dammit what you're going to see on your NLE screen, so you don't have any shocks - that's why I suggest tweaking with a colour reference chart over time to get a setting that gives you confidence.

          All I want from a field LCD monitor is to give me confidence - in focus, exposure (in combination with WFM) and colour balance - so that I know I'm keeping everything within the window of what the camera's dynamic range and codec can cope with. You can tie yourself in knots trying to get a "correct" calibration - but consistency along your own particular production chain has to be the most crucial thing.

          After all, every Tom, Dick and Harry's monitor will look different when they view your work and all you can do is use a decent known reference monitor to finalise what you create. I rely on an Apple display for my non-broadcast work.

          Robbin's suggestion of switching to 60Hz sounds like it would be worth trying, to see if the 60Hz Pluge bars work on your monitor.

          I don't know how well built and factory-calibrated your SWIT monitor is, so I can only suggest trial and error to achieve a setup you're happy with.

          Ben.
          Ben Giles BFE BAFTA

          www.matobo.co.uk

          @MatoboLtd

          Comment


            #6
            Thanks robbin for the advice and to Ben for the follow-up. The idea of switching the af101 to 60Hz momentarily in order to output the appropriate color bars with pluge is devilishly simple and ingenious. Now why didn't I think of that...?

            Thanks also Ben for emphasizing the crucial connection between the monitor and your NLE in order to ensure consistency in the production chain. I couldn't agree more and will be following your advice on this.

            Comment

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