Archive for the ‘levels’ Category

iZotope Ozone: Purchase (& Reasoning)

Sunday, January 1st, 2012

Seems a little pricey, but worthwhile in my case because it addresses two requirements that have been nagging me (before I discovered that product):

  • Has intelligent compressor, maximizing loudness and minimising dependence on manual tweaking (eqials time in post).
  • Has good-quality reverb.

It’s a plugin (DirectX /DLL), no standalone application.  Hosts / plugin formats:

  • The manual refers (Page 119) to <<Pro Tools, VST, AU and MAS versions of Ozone … (and) DirectX version>>
  • The website
    • Plug-in formats:
      • Pro Tools 7.4+ (RTAS/AudioSuite), VST, MAS, Audio Unit, DirectX
    • Plug-in host compatibility:
      • Pro Tools, Cubase, Nuendo, WaveLab, GarageBand, Logic, Audition, SONAR, ACID, REAPER, Sound Forge, Peak, Ableton Live, and many more
      • Does not mention:
        • Sony Vegas (even though I found it works in this)
        • Adobe CS5.5 Production Suite e.g. Premiere.  Can it work with this and its siblings?
  • c

Training: Den Lennie’s “Music Video” Experience

Thursday, October 27th, 2011

I attended, working on one of the camera units.  Had a great time, learnt lots, at all sorts of levels.  Even how to make good use of the Movie Slate application on my iPhone!  Link:

XDCAM-EX: Picture Profile by Marvels Film

Sunday, October 2nd, 2011
    • (Looks like a modification of Bill Ravens’ profile I found a couple or so years ago, except that profile had G-B = 32 and no white offset or ATW+2, and the Detail was not set.  Gamma was -40, STD1, Black was -12, Black Gamma was 0)
    • Matrix: On, High-Sat, Level 0, Phase -5, R-G 75, R-B 0, G-R -18, G-B -23, B-R -27, B-G 13. This gives a beautifully balanced color matrix.
    • White: on, Offset A +2, Offset B +2, Offset ATW +2. This will give you a beautiful warm picture, by elevating the reds a little bit
    • Detail: On, Level 0, Frequency +65, Crispening 0, Black limiter +75, White limiter +75. This gives a very nice definition without the artificial sharpening artifiacts. Ideal for DOF adapter shooting.
    • Gamma: Cine-1 for rich-contrast situations, Cine-3 for low-contrast situations. Make cine-1 your standard and avoid cine-4 (too noisy in the shadows).
    • Black: -3 or -4
    • Black gamma: -2. Will help to reduce noise in the blacks.
  • I choose instead the following Detail settings:
    • On: Level -5, Freq +25, Crisp +20

iPhone 4: LightMeter (app) & Theory

Sunday, October 2nd, 2011

iPhone app: “Light Meter”:

  • Uses iPhone-4’s cameras (front or rear), displaying image with overlays reporting framerate (can specify fixed e.g. 1/60), f-stop, ISO.
  • Usage with my Sony XDCAM EX3 video camera:
    • In settings, I set Stops to Halves, as that’s what the camera uses.
    • I typically use an EX3 with a Tiffen T1 IR-blocking filter.  What’s the ISO for this arrangement?
    • What do the EX3’s ND filters do to the ISO?
      • EX3 has ND1=1/8, ND2=1/64
        • (From EX3 user manual, page 50)
      • I think ISO is linear, so if Camera is 320 ISO, they imply equivalent ISOs by simple division:
        • 1080p: Clear=>320, ND1=>40, ND2=>4.5
        • 720p: Clear=>400, ND1=>50, ND2=>6.25
        • 1080i: Clear=>640, ND1=>80, ND2=>10
      • Alternatively, for ND1 filter you can leave the app’s ISO setting as Clear (no filter) and instead adjust the app’s Correction Factor to -3 EV (though it’s maybe better reserved for simulating lighting variations e.g. due to weather, as in the Exposure Value Table further below).
        • I guess from this one off case that EV is logarithmic, since 2^-3=1/8 as per ND1.
        • That guess was later confirmed by further web research (further below), stating that EV is an “additive system”, i.e. operates in the logarithmic domain, base 2.
      • Caution: being an ISO/EV newbie, I can only hope this is is all correct!
      • Nevertheless, when I tried my naive settings they worked just fine – I was successfully able to use the iPhone Light Meter to obtain a sensible camera configuration for good exposure level and (given the ND filters) the kind of shot I want (e.g. degree of DOF).  When tested on the camera, they all worked out as expected.  Cool!
  • The Light Meter app optionally displays EV400, EV100, Lux, FootCandle.  Latter units are explained in great detail at at [johnlind…] link below.
  • The app can also “log” readings – in the form of jpg images of the screen and overlays including geographical location – to a DropBox account.  For example, when I clicked the [Log] button, a jpf file appeared on my MacBook in the folder [ /Users/davidesp/Dropbox/Photos/Pocket Light Meter].

Exposure Values & Exposure Theory:

    •  <<The full name for Exposure Value, or EV, is the Additive Photographic Exposure System.  Exposure Value has two equivalent definitions.  The first defines how much light will be admitted to the film by the combination of lens aperture and shutter speed.  The second defines how much exposure is required by the combination of subject luminance (e.g., how bright it is) and film speed.  Setting a combination of aperture and shutter speed on a camera with an EV that equals the EV for the subject luminance and film speed should result in a properly exposed photograph>>
    • (The article continues at length.  For example the “Additive” element reflects the fact that this system operates in the logarithmic domain. The article also distinguishes luminance from illumination, explains units such as point-source intensity in candelas, flux in lumens, light illuminating a surface in foot-candles,  light radiated from an area in foot-Lamberts, luminence in candelas per area (square foot or square metre)
    • An EV (Exposure Value) table is presented.  I guess (?) this is useful for the iPhone app, where EV can be shifted up/down by a control, to estimate what would be needed should the lighting conditions vary:
      • -1 EV:  light sand or snow
      •  0 EV:  bright or strong hazy sun (distinct, sharp shadows)
      • +1 EV:  weak hazy sun (soft shadows; distinct sun outline in clouds)
      • +2 EV:  cloudy bright (no shadows; sun creates bright area in clouds)
      • +3 EV:  heavy overcast, but not “black” (no shadows; sun location cannot be determined)
      • +3 EV:  open shade (in shadow but 60% sky not obscured)
      • +4 EV:  deep shade (in shadow with obscured sky; under forest canopy)
    • Exposure value is a base-2 logarithmic scale
    • (This article has a more comprehensive table of EVs and weather conditions etc. than the above)


Sony XDCAM-EX3: ISO Rating(s)?

Monday, September 26th, 2011

ISO is about sensitivity.  Useful to know when using a lightmeter – e.g. the iPhone’s “Light Meter” app, where if you enter ISO it tells you the required aperture f-stop.   For the EX3 the ISO depends on several factors, such as Gain, Gamma, Recording Mode (definition and interlaced/progressive).  But a reasonable rough conservative working figure is 400.  More specifically:

  • 400 for 1080p
  • 500 for 720p
  • 800 for 1080i
    • (some say this surprising result derives from the interlaced lines each being derived from the sum of a pair of neighbouring lines)


Vimeo Upload Formats

Monday, May 2nd, 2011
  • H264 Encoder Tips:
    • Some recommend the use of Handbrake (free encoder) over that in Sony Vegas 9 and earlier.
    • Sony Vegas 10 uses an updated version of the MainConcept encoder (for H264 etc.) than Vegas 9 etc.
      • I don’t know how this compares to Handbrake.
  • Levels: Studio/Broadcast, 0-235.
    • Any levels outside this range will be preserved by the encode/decode but will get clipped at 16=black and 235=white.
    • Levels within the range will play back in Vimeo at 0-255 RGB on computer display.
  • But what of gamma/colorspace?  601 or 709 or what?
  • Framerate:
    • 30fps (as in USA) or 25fps (as in Europe etc.).
      • For nicer motion, might be worth mo-comp retiming 25 fps to 30 fps?
  • Resolution:
    • 640×480 for standard definition
    • 4:3 video, 853×480 for widescreen DV
    • 1280×720 or 1920×1080 for high definition.
  • Pixel Aspect:
    • Square, i.e. 1:1″ or “1.00”
  • Interlacing:
    • None (Progressive)
  • Encoding
    • MP4-(H264+AAC).  Other formats also possible but this one is probably the most popular.
      • H264:
        • Use 2000 kbits/sec for standard definition 4:3 video, 3000 kbits/sec for widescreen DV, or 5000 kbits/sec for high definition footage.
        • Profile = Main ?
        • Reference frames = 2 (default)
          • Each macroblock (or part of it?) can be predicted from a different reference frame.  Result can be higher quality but increased encoding time – since each Ref. Frame implies its own motion estimation.  A default of 2 or 3 is about right.  Higher values tend only to be helpful for animations.  Values above 5 rarely help.
        • Deblocking filter = Yes ?
      • AAC: 320 kbps / 44.1 kHz
      •  If you give them non-streaming source, the upload servers must do an extra preliminary pass to find the metadata, taking up more time and resources than is necessary. This has a cumulative effect on overall server response.