Problems with greenscreen

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    • #37482
      Luis Oscar MaymiLuis Oscar Maymi
      Participant

      Hello people

      I light the green screen evenly and the keying of the individual screen is almost perfect, but the problem is when the talent gets in front of the screen. I been doing the recordings in a tiny studio and due to the little space, the talent needs to get extremely close to the green screen because if they get too far from the green screen they will get out of the frame of the camcorder and because of this the shadows becomes clear in the green screen. In editing I have to use color correction, contrast, brightness, etc to try to fix this problem, but the shadows are still very noticeable. I’m making weather forecast, you can see them at http://www.juracantv.webs.com, look for the Youtube video below. (NOTE: The forecast are in Spanish) You will notice the shadows and a little something I did in the beginning.

      If you have any suggestions you could give me for the green screen problem it will be appreciated. Also let me know what you think of the forecast and what improvement I can make.

      Thanks in advance

  • #166103
    AvatarRob
    Participant

    What software are you using to do the key?

  • #166104
    Luis Oscar MaymiLuis Oscar Maymi
    Participant

    I used Sony Vegas Pro 8 for post production editing and Adobe Visual Communicator for live feed fottage. Visual Communicator is not that good in the keying but is the only sofware I have that the talent could see the radar image of the green screen. With Visual Communicator I only record the forecast and for the other footage I used Sony Video Capture and then chroma key it in Vegas.

  • #166105
    AvatarRob
    Participant

    Oh, sorry. I’m an FCP guy, so I dunno if my advice will help.

    Well, if Vegas is anything like FCP, you should be able to broaden the shade of green that is keyed out. How to go about doing it in Vegas? I’m not sure….

  • #166106
    AvatarAnonymous
    Inactive

    drop a secondary color correction on the track to mask out the green screen.play with the settings to get the result you are looking for.

    John

  • #166107
    AvatarDaryl
    Participant

    It will be tough to get your green screen right in any NLE with shadows. Get the secondary color corrector as Johnboy said and really work it. It may take some time to get the effect that you want. I had this happen to me before and I had to really put in the time tweeking thgings to get my vid to look decent

  • #166108
    AvatarAnonymous
    Inactive

    That’s a tough call withtout expensive post systems.

    The problem with greens is that the background needs to be evenly lit, the talent should be separated to avoid shadows and green spill from the reflection of the backdrop.

    In pro works you uso two light criteria: one set for the green screen and the other for the talent and this also needs separation to avoid one lighting source to affect or contaminate the other one.

    I can’t help with Vegas, but FCP may yield better results or compose in AE. In any case this will need some work that can include creating some masking through the color corrector as John says.

    Rick
    http://www.editinglinks.com

  • #166109
    Avatarcomposite1
    Member

    A while back we had a similar problem with a greenscreen shoot. On the field monitor what looked like an even lighting setup on the background turned out to be 3 shades of green when we got to post (the DP had folded up the greenscreen for transport, lots of wrinkles.) At the time we were using Vegas Pro 8’s first version and it could not separate all three ‘greens’ with the built in keyer (did I mention the talent wore a shiny green hard hat and a pastel green coat?) Having worked on other compositing shoots I made sure to light the talent and background with separate lights which saved the day. Fortunately, while the post team was stumped, I ended up using After Effects (5.5) and keyed out each individual shade of green. With some tense moments of trial and error tweaking (AFX has great tools for that) we went from having to reshoot the whole thing to getting acceptable imagery.

    Lesson learned: Despite the prior tests to make sure the talent’s colors could be keyed out successfully, a) spill from the shiny hats almost killed us (a slight dusting of talc or cornstarch powder would have knocked out the ‘shinys’, b) though we had the talent moved away from the background to cut down on shadows, moving them farther out would have helped immensely (if you’ve got room use it) and c) wrinkled greenscreens are evil and should be avoided at all costs. Now that we use our own portable collapsable greenscreens I keep a small travel iron with the kit to knock out any trouble spots. Most important, thank the production gods we had a dedicated compositing software program on hand to get the job done. You should never have to rely on a post solution, but it’s good to have one just in case!

    Just for the record as an aside, I dropped an original clip into other NLE’s to see how they handled the problem and Avid Xpress Pro, Premire Pro and FCP got smoked. I even tried Ultra CS3 and it couldn’t get rid of the ‘rogue’ colors despite having the tools that says it could. I would have tried Boris FX but I’ve never been able to make heads or tales of that program. So I always make sure we have a copy of AFX around for when ‘weird stuff’ happens.

  • #166110
    Avatarswat791
    Participant

    I haven’t used my green screen in my small “studio’ yet but when I do I have a few things I am going to try…

    First, I have marked the floor in one foot increments zero at the backdrop frame to 10′ where the camera is. I can get 12′ feet I think now that I took some things out.

    I placed a mark at 3′ in front of the backdrop for the talent to stand. If I move the backdrop frame 12-18″ further back it will be better…

    The plan…Getting two 48″ fluorescent shop light fixtures with daylight bulbs (6500k) and making a floor stand for one and a ceiling mount for the second one.

    The floor stand will be about 6″ to 8″ tall and the ceiling mount will be as close to the ceiling as possible but allowing it to move at least 10 to 15 degrees towards the screen…the stand idea is still in my head still and not on paper yet.

    Then using black foamcore I’ll make some barndoors to reduce the light spillage and focus it more on the green screen.

    I think that will work and the use of fluoresent lights will reduce the heat in my 10’x12′ “studio.”

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