Posts Tagged ‘banding

08
Aug
11

Panny af100 / af101 flat picture style for cinematic look

Update, august 11: detail settings altered – see note below

In addition to my previous article, here is our latest picture style recipe (“Scene file”) for the AF101.

We are currently in preproduction phase for our upcoming feature production “I miei geni”, a Dutch/Italian coproduction. We’ve rounded off a few days of test-shoots with our cameras, including the AF101 and we have settled for one definitive scene file.

Marvels Film cine-style profile for AF100/101:

  • Operation type:
    • FILM CAM
  • Rec. Format:
    • 1080/24P
  • Synchro Scan:
    • 180.0d
  • Detail level:
    • -6
  • Vertical detail level:
    • -6
  • Detail coring:
    • -4
  • Chroma level:
    • -4
  • Chroma phase:
    • -2
  • Master ped:
    • -2
  • Gamma:
    • Cine-Like-D
  • Matrix:
    • Norm2
Remarks:
  1. We have corrected the chroma phase to reduce a magenta hue we experienced using the Norm2 matrix.
  2. Updated august 11: Detail is dialed down to -6 instead of -7. The threshold of actually seeing electronic sharpening artifacts in the picture when zoomed in at 200% lies around the -5. I would personally not go higher as -4 at all times.  Panasonic has confirmed that -7 equals “detail off” on the AF101. Keep it at -6 or -7 for cine-style production. 
  3. Updated august 11: Coring does smooth-out noise in the image, but also all high frequency detail. The coring mechanism is not able to distinguish between noise and fine detail, such as strands of hair or fine patterns on leaves. If you deliberately want a smooth-skin-plastic-video-image though, dial this setting up… For your peace of mind: the coring setting is less effective when detail is dialed down to -4 as we do. After talking to Panasonic, we have adjusted coring in our picture style to -4, to have it “eat up noise” in the blacks and low IRE regions only. Panasonic techies advise to keep coring two points above the detail value.
  4. If you are concerned about noise in the image: don’t be! This profile is very low noise, but – and this might sound strange – not too low-noise thanks to the low coring setting. Too little noise in the image enhances the visibility of so-called “banding”, “solarization” or “posterization” in gradients. This (and all sub $10k cameras on the market today) are 8 bit cameras (4:2:2 color, having only 256 chroma levels). Masking banding artifacts in digital images (from both digital cameras and digitally scanned 35mm film) is done by adding noise! This might sound strange indeed, but this is common practice with all the prominent editing and grading facilities in the industry, for years already. So making the image even cleaner in-camera or during post can emphasize the 8-bit banding artifacts. The gradient is “broken up” (and less smooth) by the introduction of “obstacles” in the image (like  noise), forcing the imaging mechanism to calculate multiple gradients within one gradient, resulting in a perceptually smoother image.
  5. Update: If you use the Cine-D gamma setting, you should consider lighting the scene following old-school film practice: 55IRE max on faces! You will probably apply a curve to the picture, or adjust contrast and/or gamma in post -> kicking up the middle range up to around 70IRE again. Lighting caucasian skin over 55IRE with Cine D will result in problems if levels are lifted in post.
Cheers to you all, and special thanks to Jorgen Escher (http://colorbyjorg.wordpress.com) for his explanation of the coring and banding technology.
Martin Beek
Twitter: @martinbeek
http://www.martinbeek.net
IMDb: http://imdb.me/martinbeek



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