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Thread: 3-band color correction tip

  1. #1
    XDCAM HD production ScorpioProd's Avatar
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    3-band color correction tip

    Though this might seem obvious, don't overlook the power you have with the 3-band color corrector in SpeedEDIT. Since VT[4] doesn't have this capability natively, though it does with Bob Tasa's 3Wheeler, a lot of users may not be used to easily fixing things now that you couldn't before.

    For instance, say you have some blown out highlights, be they gently blown out or massively blown out (like a practical light in the shot), you can improve your video with the 3-band color corrector.

    The first thing to remember is that most camcorders and recording formats actually record up to 110IRE before clamping. While when you render out to formats such as DV for a finished project, your software codec may clamp your video to 100IRE. So effectively, that's an extra 10% of your luma detail that you are THROWING AWAY unless you do something about it.

    For instance, doing a corporate conference video right now. The early sessions the lecturn was where it should be, with no lights behind it. But for a dinner session, they moved it, and there's a practical wall light right in the shot. Well, that's massively blown out (well beyond 110IRE), and I am exposed for the person doing the speaking, of course.

    So, I go into the 3-band color corrector. First, I need to set my range of luma that will be affected, so I set the Waveform Y display for the highlight region and drop it down to -Y gain, to throw all my highlight range to black. This shows me where the area is that is affected in the shot. I then slide the range transition selector between mid to high until only the high brightness area I want is affected by the correction. With that set, I then grab the Y again and raise it till I have legal video topping out at 100IRE for the practical light in the shot. Personally, I typically go to the control tree at this point and set the exact value I want.

    By doing this, I've gained back that highest 10% of detail that would have been thrown away if I let it just get clamped at 100IRE when rendering to DV. In this case, it's not a huge difference where the practical light itself is, but the detail around it definately got better.

    In more gentle highlight blowouts, like outdoor events, you can recover even more detail with this technique.

    This is just one of the things that the 3-band corrector can let you improve in your video, you should try it out and see what other things you start using it for. (Color correction of cold source follow spots on events with tungsten stage lighting is another great use of it.)

    BTW, Bob Tasa's 3Wheeler will be coming soon to SpeedEDIT, and though the native color corrector is good, it doesn't have the masking ability that Bob's plug-in does, so his plug-in is definately still worth getting even with this native color corrector built-in. Masking brings another jump to what you can do with advanced color correction.
    Eugene
    Scorpio Productions

  2. #2
    Creator of BobFX for VT Bobt's Avatar
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    BTW, Bob Tasa's 3Wheeler on the front page for download..

    Bob
    bobt_at_bobfx_com
    www.bobfx.com
    Bob Tasa

  3. #3
    Newbie Member
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    Video Tutorial

    I dont know if it too much to ask, but if this could be done in video tutorial that would make it easier to understand and apply. Great Tip though!

    Thanks for sharing.
    See here [url]http://www.creativision.tv[/url]

  4. #4
    It's ALL about the light Paul Lara's Avatar
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    Yeah, Eugene, toss me an image or three and we can gently fold this into a tutorial!
    Don't stream it - TriCast it!

  5. #5
    'the write stuff' SBowie's Avatar
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    Just to point it out, the manual contains a couple of examples of the use of SE's color correction tools, notably at sections 5.3.3 (Low/Mid/High) and 5.3.4.6 (Practical Color Correction).
    --
    Regards, Steve
    Forum Moderator
    ("You've got to ask yourself one question ... 'Do I feel lucky?' Well, do ya, spammer?")

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