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3 films | DV bluescreen | build video camera stabilizers | Panasonic GS70 3CCD

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  • Amman Filmmakers
    Amman Filmmakers Cooperative (AFC) April 5, 2004 1) Screening of film Catch me if you can by Steven Spielberg (2002) 2) Screening of film Night Shapes by
    Message 1 of 1 , Apr 5 3:44 AM
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      Amman Filmmakers Cooperative (AFC)

      April 5, 2004

      1) Screening of film "Catch me if you can" by Steven Spielberg (2002)
      2) Screening of film "Night Shapes" by Andreas Dresen (1999)
      3) Screening of film "Talk to her" by Pedro Almodovar (2002)

      4) HOW TO: DV Chromakeys (bluescreen tips for DV)
      5) REVIEW: Panasonic PV-GS70 Mini DV Camcorder [cheapest 3CCD camera]
      6) HOW TO: Build your own video camera dolly, tracks, and cranes for 30 JD


      -------------------------------

      1) Screening of film "Catch me if you can" by Steven Spielberg (2002)
      WHEN: Monday April 5 @ 8:30pm
      WHERE: @ Books @ Cafe
      CONTACT: 4650457
      FEE: none
      Film info: http://movies.yahoo.com/shop?d==hv&cf==info&id=07745519

      -------------------------------

      2) Screening of film "Night Shapes" by Andreas Dresen (1999)
      WHEN: Tuesday April 6, 2004 @ 6:30
      WHERE: Shoman Film Center
      CONTACT: Adnan Madanat / adnan@...
      FEE: none
      Film info:
      http://www.goethe.de/uk/mon/archiv/arte/arteat10/ennachtgestalten.htm

      -------------------------------

      3) Screening of film "Talk to her" by Pedro Almodóvar (2002)
      WHEN: Wednesday April 7 @ 7pm
      WHERE: Makan House
      CONTACT: 079/5588393
      FEE: 1.5 JD
      Film info: http://movies.yahoo.com/shop?
      d==hv&cf==info&id=08406175&intl==us

      -------------------------------

      4) HOW TO: DV Chromakeys

      by Michael Kuhlman

      From the magical CGI composites of Hollywood to the meteorologist
      pointing to an animated map, the one essential element that links
      them is the key. Perhaps you'd like to make your two-year old child
      appear like Godzilla on top of a neighborhood of unsuspecting
      barbecue dads. In the olden days, that kind of composite was an
      expensive and time-consuming process of optical printing, re-
      photographing film images and hand-drawing mattes to replace the
      previously photographed foreground object, one frame at a time. We
      know an easier way.

      Same as it Ever Was

      When the consumer DV format came out in 1995, it truly was a
      milestone. 500-line resolution and far clearer color than analog S-
      VHS and Hi-8, all on a tiny tape that could be digitally copied or
      captured to a computer through a single FireWire cable, edited and
      dubbed back to the camcorder without losing any quality. Indeed, with
      the advent of faster processors, higher-speed hard-drives and ever
      increasing memory, not to mention hardware-accelerator boards,
      computers have risen to the challenge of video editing with a
      ferocity that leaves even a so-called "state-of-the-art" 500MHz
      Pentium II from 1998 in the dust. Despite all this technological
      prowess, when it comes to chromakeying, we're still confined to the
      basics: replacing the background key color with a new background. The
      trick is to leave the foreground subject intact as a clean, pure
      composite, with no telltale hint that the foreground subject is even
      part of a composite, making the illusion complete. Pre-CGI (computer
      generated graphics), filmmakers grappled with these same issues. Even
      post-CGI filmmakers have to be careful when photographing their
      actors against blue or green screen to ensure that their actors will
      composite cleanly into the yet-to-be-produced FX backgrounds in post.
      The process of creating clean composites is as much an art as a
      science, and demands tight quality control over every element seen in
      the frame.

      Chromakeying is the process of selecting a color (or small range of
      colors) in a video signal and making that color transparent. You
      place your foreground subject against some type of plain-color
      background, blue or green being the color backgrounds commonly used.
      After your software makes the color transparent, you can put anything
      you want into the background.

      4:1:1 vs. 4:2:2 - Color Matters

      Where consumer DV tends to fall short is in the way it displays and
      records color. Both consumer DV and higher-priced broadcast digital
      formats record video in component form (YUV), meaning that the color
      picture we see has a luminance signal ("Y") and two color-difference
      signals ("Y-minus red" and "Y-minus blue"). The Luminance signal
      contains the brightness and contrast information of the picture and
      is black and white when viewed by itself. Expensive broadcast digital
      formats like Digital Betacam sample color as 4:2:2, meaning the
      luminance portion of the signal is sampled at twice the resolution
      ("4") of the two color-difference signals ("2:2"). Consumer DV, in
      order to cram as much signal onto the tiny DV videotape and the 25
      Mbps DV data stream, samples color at 4:1:1 or 4(Y):1(U):1(V) or 4
      (Y):1(Y-red):1(Y-blue). So where is the green?

      The green, it turns out, is interpreted from the luminance channel.
      This is why most digital keying is done with green screens nowadays.
      Imperfect keying results in green-fringing where the key background
      is "leaking" onto our subject (especially visible around a person's
      hair) and the edges may be generally jagged and indistinct. This
      ruins the illusion just as surely as a microphone dipping into the
      shot would. Most of us are limited by economics to the 4:1:1 color
      space of DV, but the situation is not nearly as bleak as some would
      like you to believe.

      Lighting is Everything

      Lighting our green background as evenly as possible is the secret to
      a good key. In a controlled studio environment, this is usually a
      matter of placing the subject far enough away from the green screen
      so that the subject's own shadow does not fall anywhere on the screen
      behind them and then taking great pains to flood the screen with
      enough light from multiple sources to perfectly and evenly illuminate
      it. The larger the screen, and the more light you place on the
      screen, the better. On location outside, matters are a bit trickier,
      as the sun is the dominant light source. But, with trial-and-error,
      by placing the background as evenly to the direction of the sun as
      possible, quality keys can still be achieved. Using the blue sky as a
      quality chromakey background almost always invites disaster, because
      there is a subtle gradation in the sky from blue to bluish-white. If
      you're on a shoestring budget, and depending on your desired effect,
      you may be able to get away with using the sky as a blue background.
      Just be prepared to do a lot of tweaking in your software to get this
      right.

      Avoid Same-Color Clothing

      This may be obvious to some, but there are still times, even in the
      broadcast world, when the subject wears clothing that is the same
      color as the background. In post, the subject's dress or suit
      magically disappears. Fortunately, this doesn't result in naked
      embarrassment, but it does allow the background to show right through
      them, making them look like a (mostly) invisible person. There are
      two solutions at this point: reshoot or pay someone to go through the
      video frame-by-frame and fix the shot. Always direct your foreground
      subject to wear a color that is completely different from your key
      background.

      And that '80s-style mullet hairdo? Pat it down and get rid of the
      frizz. Hairs and stray fibers around the outside edge of the
      subject's sweater do not key well. A good rule to adhere to here is:
      Keep the lines on your foreground subject simple and smooth. A
      triangular-shaped Star Destroyer will key over a planet a lot better
      than a fuzzy space octopus with tiny flailing arms and appendages.

      Try to limit your subject's movements as well. A quickly moving
      subject carries with it a motion blur, where the subject and key
      background blend together a bit. The worst way to reveal your
      composite to your audience is a to show a huge colored fringe every
      time your subject quickly moves. You'll notice this phenomenon even
      during the weather, when the weatherman quickly points at something.
      This anomaly is worse in 4:1:1 DV.

      Software

      Your keying software is important as well. Often, the Chromakey
      Effect that comes standard with your editor is the most fundamental
      of keyers, basically only allowing you to select a range of colors to
      key. More advanced compositing software, such as discreet combustion
      or the specialized Ultimatte AdvantEdge will give you much better
      keys. They aren't magic, however amazing they seem, and the
      fundamentals we've discussed here still apply.

      With proper care and a vivid imagination, there are no limits to what
      kind of spectacular visual effects you can achieve through the magic
      of chromakeying. Just be sure to wave "Hi" to George Lucas on your
      way to special effects superstardom.

      Mike Kuhlman owns and operates a video production company.

      [Sidebar: DV Video Fundamentals]
      Component Video: In consumer DV, like most professional digital and
      even some professional analog video formats like Betacam SP, video is
      recorded in component form, with the brightness or black-and-white
      portion of the video signal (known as "Y") recorded separately from
      two color-difference ("Y-minus red" and "Y-minus blue") signals. The
      resulting picture is clean and free of cross-color artifacts, most
      noticably the pinkish moire sheen that occurs when, say, black lines
      going in the same direction appear too closely next to each other. A
      component video picture is like a window on the world, clear, vivid
      and with natural-looking color.

      [Sidebar: See YUV]
      If you own a DVD player and a television with component video inputs
      and outputs, try hooking up each of the three video cables that make
      up the component color picture one at a time. They are most often
      color coded green (Y), blue (Cb) and red (Cr). As you connect and
      disconnect each one, you'll see exactly how each component of the
      signal combine to make the color picture you see.

      This article originally appeared in the Videomaker Magazine April,
      2004 issue.
      For this and other articles visit us at www.videomaker.com
      ©2004 Videomaker Magazine.

      -------------------------------

      5) REVIEW: Panasonic PV-GS70 Mini DV Camcorder Test Bench [cheapest
      3CCD camera]

      by D. Eric Franks

      $1,000 [street price $750-$800 for NTSC model]

      The Panasonic PV-GS70 is the smallest and least expensive 3-CCD
      camera on the market. It would be a mistake to simply throw this
      camera into the 3-CCD category and analyze it from that perspective.
      Instead, the question we asked was: for $1,000, is this camera any
      good, regardless of the technology inside?

      Why 3-CCD?

      We found that the camera produced pleasantly saturated colors with
      properly lit scenes. We did a direct comparison with two new single-
      CCD cameras and were able to tease out a small but noticeable
      advantage (when carefully examining frame grabs); especially in how
      the GS70 represented reds in automatic mode. The difference was not
      dramatic, but we feel that this definitely shows that this camera can
      stand up to, and often beat, the latest quality consumer cameras in
      this price range. Our resolution tests revealed modest numbers, but
      this didn't seem to affect the subjective quality of the image, which
      was quite sharp, but didn't display too much contrast. The field of
      view is very wide and, as you'd expect, shows some distortion around
      the edges.

      Light Bucket

      To simplify a bit, small camcorders suffer from poor low-light
      performance, simply because they collect less light than cameras (or
      telescopes) with larger lenses (and larger mirrors). The GS70 has a
      very small lens and 1/6-inch CCDs, which are also relatively small.

      Objectively, we can say that the generous 1/3-inch CCDs and big lens
      on the largish Sony DCR-VX2100 ($3,000) give it outstanding low-light
      capabilities. Likewise, objectively, we can say that the small CCDs
      and small lens on the small GS70 ($1,000) don't give it great low-
      light capabilities. For example, under the standard fluorescents in
      our office with the camera in auto mode, there was not enough light
      to use the electronic image stabilization in some situations. (We
      certainly appreciate that the camera warns us of this condition,
      however.) The camera also felt that it needed the flash for stills
      (and indicated so on the LCD) in many normal conditions around the
      office.

      That being said, the manual controls on the GS70 do give you
      excellent control over how you manipulate the available light. In
      addition to a full-manual iris, the camera also has an electronic
      gain control. Once the iris is fully open, you can increase the
      sensitivity of the CCD from 0dB to +18dB, (in +1dB increments,
      although the numeric display only shows +3dB changes), which is quite
      a lot. Even in a very dark room, at +18dB, you are going to get a
      very bright image from this camera. You may find the image to be too
      grainy, but the point is that you have the control and you can decide
      what is too grainy for yourself.

      Wired Zoom

      As mentioned earlier, the auto features on the camera produced a nice
      image by default. The electronic image stabilization did not
      negatively impact the image, but it also was not the best that we've
      seen at stopping shakes. The manual exposure controls are great and
      manual white balance worked just fine. Manual focus was possible, but
      the focus ring was not great.

      The GS70 has both mike and phone jacks, so getting quality audio is
      possible with this camera, but ultimately up to the user. Panasonic
      includes a gimmicky little microphone/remote zoom contraption that
      connects to the camera via a 3-foot cable. You can use it to record
      voice notes to the SD card (but not while shooting video) or
      voiceover narrations (when you use 12-bit/32kHz audio). It also has a
      Record button and a zoom rocker switch that could allow you to keep
      your hands off the camera when it is mounted on the tripod. And you
      can leave the camera on the tripod: the GS70 has a top-loading tape
      mechanism. The zoom wasn't any smoother than using the wireless
      remote control or the on-camera rocker. We like gimmicks and
      features, but we would not buy this camera or any other based on such
      extras.

      Stills

      Like most other video cameras we've reviewed, you should not buy the
      GS70 because of its still image feature. At only 1.2 million pixels,
      even the cheapest digital still cameras outshoot the GS70. It's not
      that the stills of the GS70 are poor, they just aren't impressive
      anymore.

      Triple

      There are very few camcorders that compare to the Panasonic PV-GS70
      in terms of features in this size and price range. Yes, it needs
      enough light to shoot a beautiful image, but the exposure controls
      will allow you to at least get a picture even in very dark
      situations. Don't expect the three CCDs (or any other technology) to
      magically make your video "broadcast quality" (whatever that means).
      If you are looking for a good little shooter, the GS70 is a very
      portable, compact camera that shoots a nice image, has a full set of
      manual controls and the necessary microphone and headphone jacks all
      serious videographers need.

      D. Eric Franks is Videomaker's Technical Editor.

      TECH SPECS

      Format: Mini DV
      Lens: f/1.8, fl==2.45mm to 24.5mm, 10x optical zoom, 37mm filter
      diameter
      Image sensor: 3 x 1/6-inch CCD
      Gross pixels (per CCD): 460k
      Viewfinder: color
      LCD viewscreen: 2.5-inch color
      Focus: auto, manual
      Anamorphic 16:9: no
      Image Stabilization: electronic
      Exposure: auto, manual, presets (5)
      Minimum Shutter Speed: 1/60
      Maximum Shutter Speed: 1/8,000
      Iris: auto, manual
      Electronic Gain: +18dB
      White Balance: auto, manual, presets (2)
      Audio: 12-bit (default), 16-bit
      Microphone Input: 1/8-inch mini
      Headphone Output: 1/8-inch stereo mini
      Inputs: FireWire, S-video, composite
      Outputs: FireWire, S-video, composite
      Edit Interface: FireWire
      Other features: still shot (1,280 x 960), 8MB SD card, flash, wired
      remote zoom control
      Dimensions (w x h x d): 3 x 2.75 x 5.25 inches
      Weight (sans tape and battery): 1.06 lbs.

      STRENGTHS

      Sharp images, saturated colors
      Full set of manual exposure controls
      Microphone and headphone jacks

      WEAKNESSES

      Needs plenty of light
      Average image stabilization

      SUMMARY

      The PV-GS70 is a very portable, compact camera that shoots a nice
      image, has a full set of manual controls and has the necessary audio
      jacks.

      This article originally appeared in the Videomaker Magazine April,
      2004 issue.
      For this and other articles visit us at www.videomaker.com
      ©2004 Videomaker Magazine.

      -------------------------------

      6) HOW TO: Build your own video camera dolly, tracks, and cranes for 30
      J.D.

      http://www.homebuiltstabilizers.com

      The above website boasts numerous designs of low-cost video camera
      stabilizers to help a filmmaker add production value to an otherwise
      dull scene. A couple of the Cooperative films incorporated nice
      tracking shots that were produced with 30 J.D. (parts and welding)
      tracking system built by AFC's Aseel Mansour using plywood, ball
      bearing wheels, and PVC pipes, items available at your local hardware
      store. Some of the designs may need the help of professional welders,
      who can be found in Byader or Wihdat area.

      # # #
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