COLOR

LIGHTING

  • PTGui 13 beta adds control through a Patch Editor

    https://ptgui.com/beta.html

     

    Additions:

    • Patch Editor (PTGui Pro)
    • DNG output
    • Improved RAW / DNG handling
    • JPEG 2000 support
    • Performance improvements

     

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    Read more: PTGui 13 beta adds control through a Patch Editor
  • About green screens

    hackaday.com/2015/02/07/how-green-screen-worked-before-computers/

     

    www.newtek.com/blog/tips/best-green-screen-materials/

     

    www.chromawall.com/blog//chroma-key-green

     

     

    Chroma Key Green, the color of green screens is also known as Chroma Green and is valued at approximately 354C in the Pantone color matching system (PMS).

     

    Chroma Green can be broken down in many different ways. Here is green screen green as other values useful for both physical and digital production:

     

    Green Screen as RGB Color Value: 0, 177, 64
    Green Screen as CMYK Color Value: 81, 0, 92, 0
    Green Screen as Hex Color Value: #00b140
    Green Screen as Websafe Color Value: #009933

     

    Chroma Key Green is reasonably close to an 18% gray reflectance.

     

    Illuminate your green screen with an uniform source with less than 2/3 EV variation.
    The level of brightness at any given f-stop should be equivalent to a 90% white card under the same lighting.

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    Read more: About green screens
  • HDRI shooting and editing by Xuan Prada and Greg Zaal

    www.xuanprada.com/blog/2014/11/3/hdri-shooting

     

    http://blog.gregzaal.com/2016/03/16/make-your-own-hdri/

     

    http://blog.hdrihaven.com/how-to-create-high-quality-hdri/

     

    Shooting checklist

    • Full coverage of the scene (fish-eye shots)
    • Backplates for look-development (including ground or floor)
    • Macbeth chart for white balance
    • Grey ball for lighting calibration
    • Chrome ball for lighting orientation
    • Basic scene measurements
    • Material samples
    • Individual HDR artificial lighting sources if required

    Methodology

    • Plant the tripod where the action happens, stabilise it and level it
    • Set manual focus
    • Set white balance
    • Set ISO
    • Set raw+jpg
    • Set apperture
    • Metering exposure
    • Set neutral exposure
    • Read histogram and adjust neutral exposure if necessary
    • Shot slate (operator name, location, date, time, project code name, etc)
    • Set auto bracketing
    • Shot 5 to 7 exposures with 3 stops difference covering the whole environment
    • Place the aromatic kit where the tripod was placed, and take 3 exposures. Keep half of the grey sphere hit by the sun and half in shade.
    • Place the Macbeth chart 1m away from tripod on the floor and take 3 exposures
    • Take backplates and ground/floor texture references
    • Shoot reference materials
    • Write down measurements of the scene, specially if you are shooting interiors.
    • If shooting artificial lights take HDR samples of each individual lighting source.

    Exposures starting point

    • Day light sun visible ISO 100 F22
    • Day light sun hidden ISO 100 F16
    • Cloudy ISO 320 F16
    • Sunrise/Sunset ISO 100 F11
    • Interior well lit ISO 320 F16
    • Interior ambient bright ISO 320 F10
    • Interior bad light ISO 640 F10
    • Interior ambient dark ISO 640 F8
    • Low light situation ISO 640 F5

     

    NOTE: The goal is to clean the initial individual brackets before or at merging time as much as possible.
    This means:

    • keeping original shooting metadata
    • de-fringing
    • removing aberration (through camera lens data or automatically)
    • at 32 bit
    • in ACEScg (or ACES) wherever possible

     

    Here are the tips for using the chromatic ball in VFX projects, written in English:
    https://www.linkedin.com/posts/bellrodrigo_here-are-the-tips-for-using-the-chromatic-activity-7200950595438940160-AGBp

     

    Tips for Using the Chromatic Ball in VFX Projects**

    The chromatic ball is an invaluable tool in VFX work, helping to capture lighting and reflection data crucial for integrating CGI elements seamlessly. Here are some tips to maximize its effectiveness:

     

    1. **Positioning**:
    – Place the chromatic ball in the same lighting conditions as the main subject. Ensure it is visible in the camera frame but not obstructing the main action.
    – Ideally, place the ball where the CGI elements will be integrated to match the lighting and reflections accurately.

     

    2. **Recording Reference Footage**:
    – Capture reference footage of the chromatic ball at the beginning and end of each scene or lighting setup. This ensures you have consistent lighting data for the entire shoot.

     

    3. **Consistent Angles**:
    – Use consistent camera angles and heights when recording the chromatic ball. This helps in comparing and matching lighting setups across different shots.

     

    4. **Combine with a Gray Ball**:
    – Use a gray ball alongside the chromatic ball. The gray ball provides a neutral reference for exposure and color balance, complementing the chromatic ball’s reflection data.

     

    5. **Marking Positions**:
    – Mark the position of the chromatic ball on the set to ensure consistency when shooting multiple takes or different camera angles.

     

    6. **Lighting Analysis**:
    – Analyze the chromatic ball footage to understand the light sources, intensity, direction, and color temperature. This information is crucial for creating realistic CGI lighting and shadows.

     

    7. **Reflection Analysis**:
    – Use the chromatic ball to capture the environment’s reflections. This helps in accurately reflecting the CGI elements within the same scene, making them blend seamlessly.

     

    8. **Use HDRI**:
    – Capture High Dynamic Range Imagery (HDRI) of the chromatic ball. HDRI provides detailed lighting information and can be used to light CGI scenes with greater realism.

     

    9. **Communication with VFX Team**:
    – Ensure that the VFX team is aware of the chromatic ball’s data and how it was captured. Clear communication ensures that the data is used effectively in post-production.

     

    10. **Post-Production Adjustments**:
    – In post-production, use the chromatic ball data to adjust the CGI elements’ lighting and reflections. This ensures that the final output is visually cohesive and realistic.

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    Read more: HDRI shooting and editing by Xuan Prada and Greg Zaal
  • Christopher Butler – Understanding the Eye-Mind Connection – Vision is a mental process

    https://www.chrbutler.com/understanding-the-eye-mind-connection

     

    The intricate relationship between the eyes and the brain, often termed the eye-mind connection, reveals that vision is predominantly a cognitive process. This understanding has profound implications for fields such as design, where capturing and maintaining attention is paramount. This essay delves into the nuances of visual perception, the brain’s role in interpreting visual data, and how this knowledge can be applied to effective design strategies.

     

    This cognitive aspect of vision is evident in phenomena such as optical illusions, where the brain interprets visual information in a way that contradicts physical reality. These illusions underscore that what we “see” is not merely a direct recording of the external world but a constructed experience shaped by cognitive processes.

     

    Understanding the cognitive nature of vision is crucial for effective design. Designers must consider how the brain processes visual information to create compelling and engaging visuals. This involves several key principles:

    1. Attention and Engagement
    2. Visual Hierarchy
    3. Cognitive Load Management
    4. Context and Meaning

     

     

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    Read more: Christopher Butler – Understanding the Eye-Mind Connection – Vision is a mental process