Anamorphic Squeeze and 3/2 Pull Down

Discussion in 'Archived Threads 2001-2004' started by Kevin Potts, May 25, 2002.

  1. Kevin Potts

    Kevin Potts Second Unit

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    Stupid Question:

    Is the Anamorphic Squeeze and the 3/2 Pull Down the same thing? If not, what is the difference between the two?

    I'm planning on purchasing a "Big Screen" TV in the near future and I'm still in the R&D (research and decision) stage.

    I'm looking at one of the Panny models so if anyone has any advice or info, please feel free to share.

    Thanks
     
  2. Mark Larson

    Mark Larson Supporting Actor

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    Yup, very stupid questions. [​IMG]
    Anamorphic squeeze is the trick a big screen TV does to use all available scanlines for widescreen viewing. This is not anamorphic in itself, but is used because anamorphic widescreen transfers use it.
    3-2 pulldown is something done in a DVD player to make it display film (24 fps) for an NTSC (60 fields per second) display. Secrets.
    Anamorphic widescreen is aaaaaaargh just read the HTF Primer.
     
  3. Allan Jayne

    Allan Jayne Cinematographer

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    If you have never seen the anamorphic squeeze (aka vertical squeeze trick aka 16:9 mode on a 4:3 TV) see if you can do this:
    On your computer monitor there should be a control or menu item labeled "vertical size" or "vsize" or "height" or a tiny screen shaped rectangle with an up and down double arrowhead in it. Manipulate this control and you will see the picture shrink and the proportions change to make things squatty while all the scan lines are still there.
    If the TV is playing an "anamorphic" aka 16:9 enhanced DVD and the DVD player was in 16:9 mode, the 4:3 full screen picture will show things disproportionately tall and thin and doing the anamorphic squeeze will make things look right.
    If your 4:3 TV does not have "the anamorphic squeeze" available, then set the DVD player to 4:3 mode and the player will reformat the picture to look right on the screen, but since the scan lines remain evenly spaced over the screen, fewer will be within the picture and the pictue quality will be a bit less.
    Note: With the DVD player in 16:9 mode and the squeeze on the TV, the finished picture and black bars should have the same dimensions as with the DVD player in 4:3 mode and the squeeze not on the TV, except for minor calibration differences.
    A few TV sets fake it, their 16:9 mode is not a true squeeze, the scan lines remain evenly spaced out over the screen and the picture is digested to fit in the middle with the same kind of quality loss as with the DVD player in 4:3 mode.
    (Video can be stretched any way you want, it is up to you to decide what looks best within the limited selection of squeeze modes and ranges etc..)
    To see 3-2 pulldown in effect, record a movie and then single step the VCR. You will see a 3, 2, 3, 2 repeat pattern since 24 frames per second of film do not divide evenly into 60 interlaced fields (60 full frames if progressive scan) of video. The 3-2 pulldown recognition and optimizing in a DVD player or TV (pertains to progresive scan only) makes each progressive scan frame out of matching even and odd fields. Without this you may see from time to time a minute flash of fringed ghosting during side to side movement as a progressive scan video frame with odd scan lines from one film frame and even scan lines from the next film frame was displayed. Alternatively you may see the entire picture blur when things were previously stationary and something started moving, if not blurry all the time compared with turning off progressive and letting it do interlaced scanning. Here it is synthesizing the even scan lines from the odd scan lines of the same frame (or vice versa) instead of use real even and odd scan line picture detail.
    Some equipment (TV sets, line doublers) come close in picture quality (intra-field motion adaptive de-interlacing) even when not doing 3-2 pulldown recognition and optimizing. The recognition is not perfect. The best DVD players must not only recognize 3-2 pulldown, they must come close when the recognition fails or the source was not 24 fps film.
    (If the movie was not from 24 fps film or was incorrectly committed to video, you will not see the 3-2 repeat pattern. Try recording a different movie.)
    Video hints:
    http://members.aol.com/ajaynejr/viddoubl.htm
     
  4. Kevin Potts

    Kevin Potts Second Unit

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    Thanks for the info guys. For some reason I was thinking they were the same thing. Glad you all could clear it up for me.

    Now for my next question-

    Which models of Projection HDTV's can do the "squeeze". There seem to be many different names the manufacturers have come up with for the "squeeze" and I'm not sure which ones are the real deal.
     
  5. Matt Stone

    Matt Stone Lead Actor

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    Which TVs are you looking at?
     
  6. Kevin Potts

    Kevin Potts Second Unit

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    Matt,

    Right now I'm looking at;

    RCA D61130
    Panasonic PT-61HX41
    Hitachi 61UDX10B
    Sony KP61HS30
    Toshiba 61H71

    Just about all of them have some kind of 16:9 mode or some other such thing listed in the specs. I'm just not sure if they're talking about the "squeeze" or some other feature.
     
  7. Matt Stone

    Matt Stone Lead Actor

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    I know the Tosh and Sony has anamorphic squeeze...and I would assume the Panny does, but I don't know about the others.
     

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