Green screen blow out

Discussion in 'Digital Video' started by matteusclement, Jul 19, 2013.

  1. macrumors 65816

    matteusclement

    Joined:
    Jan 26, 2008
    Location:
    victoria
    #1
    I have a project where a small bit of my light came through the green screen (there was a window behind it).

    It's definitely blown out and to make matters worse, the talent is playing drums through that part, so it's not like I can do a quick and dirty with a mask.

    It's blown out at pure white. Is there a way I can take out that pure white with a luma key or something?

    Premiere pro cs6 using ultra key but I have access to after effects too.
     
  2. simsaladimbamba

    Joined:
    Nov 28, 2010
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    located
    #2
    Can you post a screenshot or even small sample in original resolution for others to take a look at it and maybe even try it for themselves (TIFF or MOV with original codec)?

    I have had a similar situation (green screen with window behind, but luckily it had drapes) and have had good results with Keylight in AE.

    Btw, what recording format and codec is the footage stored in? I shot with the BMCC and the DNxHD and RAW modes, thus the footage has much much more information to key than shooting green screen with a DSLR and its funny H.264 mess.
     
  3. thread starter macrumors 65816

    matteusclement

    Joined:
    Jan 26, 2008
    Location:
    victoria
    #3
    Guess dropbox would be the best to post that clip?

    I will post a photo when I get home.

    it was with a sony nx100.

    the blow out it totally white, no green at all.

    it would be nice if I could key out JUST 99-100% white.

    PLEASE help as I cannot reshoot this. The performers were from africa.
     
  4. simsaladimbamba

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    #4
    Dropbox is okay. Depending on the visual information present, you might have to do a mask by hand.
     
  5. thread starter macrumors 65816

    matteusclement

    Joined:
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    victoria
    #5
    here is a link, please let me know if it works.
    this one isn't as bad but the file size was smaller than the others
    http://sdrv.ms/16QPCen
     
  6. macrumors regular

    Joined:
    Dec 11, 2012
    #6
    If its pure white, then I would first start with a luma key to see where that gets me.

    second, I would duplicate the layer (in after effects, much easier with this sort of work) and crunch the colors and basically create an alpha matte (track matte) to key itself out.. if the white is indeed very white, then when you use the levels or curves filter to crush the colors, it should stay..

    Try that, but mask just the area around the white to isolate the problem area.
     
  7. simsaladimbamba

    Joined:
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    #7
    Sorry for the late reply, but my download speed is a bit slow (100 MB in an hour) and only the third time trying to download the MTS was successful.

    I tried your footage in AE with the Keylight 1.2 plugin (good tut here) and it was okay to key, except the white part in the middle between the musicians.
    Maybe you can adjust that with a mask you have to animate when the dancer has her arms before them.

    Also know, that MTS footage is 4:2:0 and does contain at lot less information than 4:2:2 or RAW footage, thus keying compressed footage is a bit more cumbersome.

    Next time just use some thick dark fabric behind the green screen.
     
  8. macrumors regular

    Joined:
    Dec 11, 2012
    #8
    Do you have the Keylight plug in for after effects? (included in the last few versions)

    I downloaded your clip and within a few mins I got some pretty great results. Some manual masking will have to be done to handle the light behind it but it is coming out pretty good.
     
  9. macrumors regular

    Joined:
    Dec 11, 2012
    #9
    Yes.. while that camera isnt a total production camera, it can be used with decent rusults.

    And if he is using a sony nx100 (rx100 correct) then he doesnt have the cash to run out and buy an Alexa.. or a RED.. or even a P2 based camera.

    and whats this 'RAW' format for video you speak of? If you are referring to the raw camera files (such as RED or an Alexa) then yes it is better, but it is still not called RAW.. perhaps Raw or Native RED, besides, Alexa can shoot in pro res 4444, which is pretty nice but I dont consider that RAW.
     
  10. simsaladimbamba

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    #10
    I meant DNG files from the BMCC. The BMCC can be had for rent for 100 USD or less per day.
     
  11. thread starter macrumors 65816

    matteusclement

    Joined:
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    Location:
    victoria
    #11
    I knew I could manually mask, I was just hoping to avoid it with an alternitive key.

    THIS IS GOING TO SUCK.

    I have 48 videos to deal with. UGH.
     
  12. thread starter macrumors 65816

    matteusclement

    Joined:
    Jan 26, 2008
    Location:
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    #12
    it's early but it just might work

    So in premiere pro I think i found a solution.

    Using the ultra key first to take out the green, I have used the COLOR key next. The order matters BTW.

    With a color tolerance of 50 and the others set at 0, it has pulled clean in the dancing videos. I am now trying it with the others.
     
  13. thread starter macrumors 65816

    matteusclement

    Joined:
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    #13
    UPDATE: did not work

    update

    I have tried this attempt in other clips and it has not worked.

    I have no idea what I should try now.
     
  14. macrumors regular

    Joined:
    Feb 25, 2011
    Location:
    Montréal, QC
    #14
    personnaly, I use The Foundry Nuke for my keying. You might have more luck with that if you can get your hands on it and follow a few tutorials :cool:
     
  15. macrumors 68020

    Joined:
    Jun 26, 2002
    #15
    manual mask it if you have the time and resources.
    if not then maybe add a creative around that area e.g background with similar hilites.
    its a tough pill to swallow when you run into these kinds of issue.
    just like in hollywood, re-shoot or deal with it.

    good luck and all the above tips do work :)
     
  16. thread starter macrumors 65816

    matteusclement

    Joined:
    Jan 26, 2008
    Location:
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    #16
    is it possible that I rotoscope it in AE?

    I don't mind manually pulling it out, i am just looking for the fastest way to do it.
     
  17. macrumors 68020

    Joined:
    Jun 26, 2002
    #17
    You can by adding a duplicate layer of the solid green screen over it.

    Its just reverse work from masking the section period.

    Not sure which direction you are going with this as far as background goes.

    Maybe show an example. It might help determine your workflow.
     

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