Any easier way to blue screen stop motion animation?

Discussion in 'Professional Video Production' started by Luis ORTEGA, Apr 8, 2005.

  1. Luis ORTEGA

    Luis ORTEGA Guest

    We are using a digital camera to capture stills for a stop motion animation.
    Obviously, there are a large number of stills for every few seconds of real
    time action. We are using about 12 stills to capture what will be 1 second
    of real time action. Before shooting each still image, we reposition the
    animation characters on the stage in the normal stop motion technique.
    We shoot the stills with a simple solid colour background.
    When we have the animation action scene shot, we open all of the images in
    Photoshop and select the background and create an alpha channel for the
    background area.
    Then we import all of the stills into Premiere Pro and knock out the
    backgrounds of each still using the alpha keying filter, so that the desired
    background shows through from the lower track.
    As you can see, this process is incredibly tedious!
    We can't use the batch action option in Photoshop since each still has the
    animated characters positioned slightly differently.
    Is there an easier way to accomplish this?
    If we brought the digital stills directly into Premiere Pro first, we could
    use the colour key filter to knock out the solid colour backgrounds, but
    this is sometimes not such a clean result on the edges of the shapes and
    requires fiddling with the keying controls. Also, it has to be done for each
    clip on the timeline anyway.
    Does Premiere Pro offer some automation to this process? Could all of the
    stills on the timeline be somehow grouped and worked on all at once?
    I am aware that if we connected a camcorder to a computer and used something
    like Sceneanalyzer, each capture would be saved as part of a single avi file
    and this would make the process much faster, but unfortunately, for this
    project we are unable to do the filming where the computers are and are
    forced to use digital cameras instead. These are my students' projects and
    they are not able to capture from a camcorder connected to a computer, and
    some don't even have a camcorder to use anyway.
    I would greatly appreciate it if anyone can advise me on some way to make
    this process work faster.
    Thanks a lot.
    Luis ORTEGA, Apr 8, 2005
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  2. Luis ORTEGA

    nap Guest

    do you have After Effects in you class?
    nap, Apr 8, 2005
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  3. Luis ORTEGA

    Luis ORTEGA Guest

    Yes, we have the 6.5 version.

    Luis ORTEGA, Apr 8, 2005
  4. Luis ORTEGA

    nap Guest

    would think you can replace both the Photoshop and Premiere Step with AE?
    Have you tried this?
    nap, Apr 8, 2005
  5. Luis ORTEGA

    Luis ORTEGA Guest

    I haven't tried AE yet, but I'm not sure how it would save the work of
    having to knock out the blue screen area of each still in a timeline.
    Can it group all of the stills into one single file so that the blue screen
    could be removed from all of them at the same time as if they were a single
    Thanks for your help.
    Luis ORTEGA, Apr 8, 2005
  6. Luis ORTEGA

    nap Guest

    yes.. Especially if they are sequentially numbered frames. Otherwise....
    make an uncompressed AVI/MOV with them in Premiere or AE. Then take that and
    do the keying with AE.

    Do it on a scene basis so that you are working with frames that have
    backgrounds that are similar.

    In otherwords.. I would do all of my animation forst, Then edit the
    animations together to exactly the frames I want to use, with handles. After
    you have done that is the time to do the background removal. That saves
    doing any processing on frames you are not going to use.
    nap, Apr 8, 2005
  7. Luis ORTEGA

    Luis ORTEGA Guest

    Thanks a lot!
    I do understand the part that you said about first laying out the series of
    stills on a timeline and then using the making movie in Premiere to turn
    them into a single file, then bringing that file back into a new timeline
    and applying the keying effects to that. What a great idea.
    Will there be any degredation of the visual quality in doing this? Should
    the kids set their digital cameras to capture at some level of resolution
    higher than what might be needed to fill a typical video frame (720 x 576
    pixels at 72 dpi for PAL)? And if so, should they first do a batch action
    resampling of all the stills in a particular scene using Photoshop before
    bringing them into Premiere?
    I would think that if the digital stills were too high a resolution when
    imported into the Premiere timeline they might be too large visually to be
    seen completely in the monitor window.
    Luis ORTEGA, Apr 8, 2005
  8. Luis ORTEGA

    nap Guest

    If you go with uncompressed movies for your interim work it should be just
    fine. Never render to the DV codec until you are completely through with all
    of your intermediate steps.

    The higher the better.. Balance it with your storage / time requirements

    And if so, should they first do a batch action
    I don;t think they need to.

    Just shrink the window down a little. Premiere can deal with large frames

    It is best to work with the highest res and NO compression for keying or
    rotoing, repositioning..

    nap, Apr 8, 2005
  9. You should be able to do it pretty well with Premiere or After Effects.
    I suspect the problem isn't in the software though. There are two
    really important things to remember in 'blue' screening.

    1) Choose a key-out background which has the least resemblence to
    any other color in your set. This should be a _MATTE_ finish.
    2) Lighting lighting lighting.

    You want your lights so that the keyout backdrop is evenly lit with a
    diffuse even lighting. It should also be lit so that it does not reflect
    onto your foreground or catch shadows from your foreground.

    The best way to do this is make your set _BIG_ Put your keyout colored
    materials as far from the action as you possibly can. Try moving both
    light and dark coloured objects near the keyout so you can spot reflections
    hilights, and gradiations. Do this and you'll get much better results.

    ALSO: For digital capture. Take as high-resolutation images as you
    can AND, take UNCOMPRESSED images. JPEG or PNG will give you weird
    colour-bleed on the edges by the nature of the compression algorithm.

    I do my digital capture from a Mac, so I was able to set up a unix
    cronjob from it to go and fetch files from my camera while I am
    photographing. That way, I never run out of space on the camera and
    I don't have to move the camera in the middle of shooting to download
    my stills. It's also non-interruptive to the playback in FrameThief.

    So I actually end up with two copies of my movie. One that I record
    in FrameThief at 640x480 (my realtime test and playback version) and
    the high-res (uncompressed TIF) version I get from my camera. That
    way I can both see what I'm doing and get good data for editing.
    Later, if I decide I'm only going for TV quality, I can just change
    my output size and be done with it.

    One final note: In AfterEffects, you can actually select multiple
    keyout colours and have each applied. So if your blues are grainy,
    you could select 2 or 3 blues and get them all. The disadvantage of
    this is that it takes longer to process. OTOH, at least you're not
    doing it by hand.

    Good luck!

    Samantha, the Feminist Goddess, Apr 8, 2005
  10. Luis ORTEGA

    Luis ORTEGA Guest

    I just wanted to report on what I finally found to do about this problem to
    share it with others.
    Once I finish shooting a series of stills using a digital camera, I was able
    to just download them into a computer, import them into Premiere Pro, and
    automate them to timeline in a sequence. I set the default frame length that
    I wanted for stills in Premiere before importing the stills, since the
    default is 150 frames, and I wanted to use 2 or 3 frames per still.
    The files were already named sequentially in the digital camera and were set
    to a higher pixel size than would be needed for a video frame. A coloured
    background was used behind all of the shots as in normal bluescreening
    Once the series of stills were on the timeline, I just stretched the first
    and and last still to about 2 seconds each to create handles for editing,
    then I created a new sequence and nested the sequence containing all the
    stills into that one.
    All of the stills became a single clip in the nested sequence and then I was
    able to apply the colour keying effect only once.
    No manipulation of the original stills was needed or preliminary rendering
    of images, so the quality was maintained and the time it took to get from
    hundreds of stills to a single clip was about 1/100th the time of my
    original method!
    If the image size was too big for the video frame because of the higher
    resolution of the digital camera stills, it was very simple to just scale
    the single clip down to fit the frame size in Premiere.
    This procedure was suggested to me by another poster in the Creative Cow
    Premiere forum.
    Thanks a lot to all who offered their advice. These newsgroups are the best
    resource in the world for problem solving and sharing ideas.
    Luis ORTEGA, Apr 9, 2005
  11. Luis ORTEGA

    nap Guest

    good news. Some variation of what you're doing is fine. I would not scale
    down until I was rendering to a codec.. do all the image processing at the
    highest rez.

    anyway.. glad you got things underway.
    nap, Apr 9, 2005
  12. Luis ORTEGA

    Seattle Eric Guest

    Not true. A WAND selection merely selects at a given location. You
    should be able to find an unused corner that always has no critical
    stuff in it, or, switch to a different corner for that sequence.

    As to the tedium: welcome to animation.
    Seattle Eric, Apr 10, 2005
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