Forum Replies Created

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  • Ed Dooley

    May 14, 2007 at 7:26 pm in reply to: Darkness/Contrast problem

    There’s no substitute for a good calibrated video monitor. But there are a number
    of ways to calibrate a regular TV to give a fairly decent image. Google it and you’ll find a few. Here’s one I’ve had for a while (don’t ask me to defend its method, it’s not my doing!)
    Ed

    If your monitor does not have a “blue-switch” as referenced below, then you need to use a Wratten #47 filter which you can purchase at any photo store. This blue filter will work when you place it in front of your eye as you make the adjustments noted below. Where there is a reference to the blue-switch substitute if for the Wratten filter.

    Setting up a monitor for proper color rendition is probably the single most important thing one can do on location. Here is a simple method in maintaining a color-accurate picture in the field.

    1. Allow the monitor to warm up for a few minutes.

    2. Block any reflections on the screen and make sure the lighting in the location is not that bright around the monitor.

    3. Switch your camera or the source you are feeding into the monitor into bars.

    4. Set the ‘contrast’, which is also called ‘picture’ on some monitors to its midpoint.

    5. Turn the ‘chroma’ also called ‘color’ on some monitors all the way down until the color bars are shades of black and white

    Notice the three Picture Lineup Generating Equipment bars on the bottom right called PLuGE bars. The left one is set at 3.5 units, so it is effectively supposed to be invisible. The middle one is set for 7.5 units or ‘standard black’ in NTSC. The right-most bar is set for 11.5 units and is slightly brighter than what black represents on your monitor.

    6. Adjust the ‘brightness’ control until the middle (7.5 units) PLuGE bar is not quite visible. The lightest bar on the right (11.5 units) should be barely visible. The right bar (3.5 units) disappears when you do this.

    Since 7.5 units is as dark as video gets in the US (analog), you should not see any difference between the left bar (3.5 units) and the middle bar (7.5 units). There should be no dividing line between these two bars. In fact, both should disappear together based on the 7.5 bar, which ‘just’ disappears. The only division you should see is between 11.5 and 7.5

    Next we want to set the ‘contrast’ control on the monitor for a proper white level.

    7. Turn the ‘contrast’ all the way up. The white (100 unit) bar which is the fat brightest white bar in the lower left hand side of the screen will get real bright. Prior to turning the contrast pot down, you will notice that the 11.5 units bar is now brighter than it was when we just set it and that you can see the space where the 3.5 and the 7.5 units were.

    8. Adjust the contrast down until the three PLuGE bars go back to the point where the 7.5 is barely visible and the 3.5 is not longer visible. The 11.5 is once again slightly visible.

    Next we adjust the color portion of the picture. All professional monitors have a ‘blue-only’ switch. The instructions below are for a monitor that has it. If you do not have a blue-switch on your monitor, you need to purchase a Wratten#47 filter. This filter is blue. Place it in front of your eye and follow the instructions below substituting the references to the blue switch for the Wratten filter..

    9. Press it. When you do, you are using only the blue gun in the tube to make an image. On some monitors the bars will turn shades of black and white. On others, the bars will turn deep blue.

    Notice that the four bars visible are either a shade of black and white or are shades of deep blue. Also notice that each column is actually split toward the bottom of the bars making for four tall bars with four little sub bars. If the tint and color are correct, these two elements in each column should appear to be the same color or contrast. Most likely, they may need adjustment.

    We are now going to make sure all the bars are the same color (as close as they can be). Now this next step is a ‘two place viewing’ procedure.

    10. With the ‘blue switch’ still depressed, turn the ‘chroma’ or ‘color’ knob until the split vertical bars on the outermost far left and the bars at the outermost far right are of equal brightness or hue if your monitor shows them as blue. You’re trying to get the two vertical bars on top to match with the two small sub bars below them. All four bars (two big and two small) should appear to have the same value. Let me say it again. When you have it right, all four of the bars (the left bar with its sub and the right bar with its sub) should appear to have the same hue or contrast.

    11. Now adjust the ‘Hue control’ or ‘Phase’ until the two inner bars are also equal with their sub bars and each other.

    At this point as you look at the screen all the four vertical columns including the little sub bars should look equal in color intensity or brightness depending on what you monitor does when you press ‘blue only’.

    Unless you have a waveform and vectorscope with, your monitor is now the only way for you to see how accurate your video is. Don’t adjust it!

  • Ed Dooley

    May 11, 2007 at 4:55 pm in reply to: Beta Sp to DV

    But 4:4:4 color sampling translates into huge file size, and it won’t be any better
    quality when you start with Beta-SP, which isn’t 4:4:4. As an analog format it translates
    roughly into 3:1:1. Putting it into a 4:4:4 color space doesn’t do anything for the quality.
    Ed

  • Ed Dooley

    May 11, 2007 at 4:10 pm in reply to: Beta Sp to DV

    DVCPro-50 is much better than DV (CAM or otherwise). It’s twice the data-rate. Photo J-PEG at 75% is pretty good too. We do some projects that originated on Beta in the DVCPro50 codec and it looks great.
    Ed

  • Ed Dooley

    May 11, 2007 at 3:51 pm in reply to: bad quality with mpeg-4

    Two things, give more information if you need help. One- There are hundreds of variables, like:
    Are you trying to capture to your system drive? As was asked before, what format are you capturing from? Tell us what you’re doing or you can’t get helped.
    Two-Reading your own post before hitting the send button might help too. Reread what you wrote below and see if anyone could possibly understand your problem from what you wrote.
    Ed

    [s_oboyle] “I can’t use NTSC. It doesn’t work. I get dropped frames. Mpeg-4 is the only one that drops frames. “

  • Ed Dooley

    May 8, 2007 at 9:02 pm in reply to: kona ls or IO la

    The Kona has SDI and AES, the IO doesn’t. You can hook your IO up to your laptop, not so with the Kona.
    Ed

  • Ed Dooley

    May 7, 2007 at 4:24 pm in reply to: Black Bars on sides of 720×486 IOLA beta footage

    Thanks guys,
    But AJA themselves don’t think the 5-6 pixels I have on each side is normal, and it’s only recently been that much using my IOLA, which I’ve owned for a few years.
    Further testing using other video sources, as well as outputting bars from
    FCP direct then bringing them back in to FCP shows them too.
    AJA thinks it’s odd enough that I’m receiving a brand new IOLA by FedEx any minute now.
    They’re a great company for customer service.
    I’ve always had a few pixels of black, but this went a bit further than “normal”.
    Ed

  • Ed Dooley

    May 3, 2007 at 3:38 am in reply to: Black Bars on sides of 720×486 IOLA beta footage

    According to AJA, this is unusual. I have a bunch of DVC Pro50 and other Beta sourced clips that when opened in QT Player, fill the 720, but my Beta stuff and the Bars I generate from FCP through the IO don’t.
    AJA is Fed Exing me a new IO tomorrow.
    Ed

  • Ed Dooley

    May 2, 2007 at 8:29 pm in reply to: Black Bars on sides of 720×486 IOLA beta footage

    Thanks Jeremy,
    It’s OK as far as overscan, it’s the TV station I’m worried about. I don’t want to run afoul of
    their engineers and have to start over. I’ve hooked up a DVD player through the IO now too, to eliminate the Beta deck as the problem, and I’m getting black bars still.
    Ed

  • Ed Dooley

    May 2, 2007 at 4:58 pm in reply to: Uncompressed HD over firewire?

    Jason, You’re missing the point, get your bits and bytes right.
    A mb is a mega *bit* (or 1/8th of a megabyte), a MB is a mega *byte* (or 8 megabits). FW400 has a theoretical speed of 400mb, or 50MB. For FW800 it’s 800mb, or 100MB.
    Ed

    [Jason] “Firewire 800 is meant to be twice the speed of firewire 400 which has a speed of 50mb/sec, the 800 mean 800mbits/sec which is slower than a mb.”

  • Ed Dooley

    May 1, 2007 at 9:36 pm in reply to: Uncompressed HD over firewire?

    Firewire 800 is 800mb/sec. It’s also 100MB/sec. In an ideal world that is. 🙂
    Ed

    [Jason] “The new AJA IO HD looks great but I’m confused as Uncompressed HD can be more than 100mb/sec yet firewire800 is only 100mb/sec. How does this work or does it not actially do uncompressed?”

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