Archive for the ‘grading’ Category

MBR Color Corrector: Update to Version 2

Wednesday, December 26th, 2012

MBR Color Corrector, by Matt Roberts, is a plugin Effect for Adobe Premiere and After Effects, to automatically color correct movie clips / footage featuring a Gretag MacBeth / X-Rite ColorChecker chart or card in-shot, e.g. at the beginning or end of a scene or take.

This provides an alternative to manual (hence subjective and probably iterative) color adjustments in conventional Effects in the editing application (Premiere or After Effects).

When applied appropriately, the workflow-result can be improved productivity and quality, with reduced (as opposed to avoided) dependency/demand on Colorist expertise and accurate color monitors etc.  It not only handles typical color temperature issues but also, to a useful degree, non-linear luminance and color “twisting” inherent in certain cameras and lighting conditions.

In addition to color correction, MBR Color Corrector can also be used for color matching, e.g. to match a mood, as previously established in an example prepared by a Colorist, provided that example likewise contains some frames featuring a Gretag Macbeth / X-Rite color chart or card.

The new version (v.2) features:

  • Mac support.
  • An improved, more intuitive, user interface.
  • Keyframes on everything that effects the output.

The free (gratuit) functionality is almost complete (no watermarks etc.) and in my experience has certainly been useful on real projects.  The paid version has greater efficiency and functionality, and encourages the developer to keep developing.  See the product web-page for more details.

See images in corresponding entry in my main blog.

Matt Roberts (MBR’s) Automatic Color (Chart) Corrector

Tuesday, February 14th, 2012

How about an After Effects plugin for automatically grading any footage featuring a Gretag Macbeth color chart in-shot (e.g. at the beginning and/or end of shot)?  Matt Roberts’ new plugin, still “steaming off the press”, works in Premiere as well as After Effects, and has been tested in CS5 and CS5.5.  You simply pause on a frame featuring a color chart in-shot, place corner locators to identify that chart, and ‘Go”.  It not only fixes white balance but also adjusts for saturation and compensates for certain kinds of “color twisting” defects such as can occur in cameras.    Subsequent “expert tweaks” can then be made if preferred, e.g. 20% saturation reduction for “film look”.  The free version works in 8 bits, the paid (£50) one (in the process of being made available on works in 32 bits, multithreaded etc.  To find out more and to download it:

Example: Canon 7D Video Footage:

Canon 7D before correctionCanon 7D after correction

So what’s the point of this plugin?  Greater quality, reliability and productivity, as compared to traditional color correctors, as explained below.

Those with an eye for accurate color reproduction from video footage will be familiar with traditional tools such as 3-way color correctors and meters such as waveform monitors and vectorscopes.   All proper Non Linear Editing systems (NLE’s) have these.  Generally-speaking such tools work well, but sometimes in practice the situation can become confused when for example a subject’s “white”(assumed) shirt is in fact off-white, or when tinted light mirror-reflects off skin or results from camera filters.  Easy to understand in retrospect, but initially can cause “running round in circles” of interative adjustment and re-checking.  Furthermore, some cameras have peaks, pits, twists and ambiguities (e.g. infra-red) in their colour response that many such correctors cannot correct in a straightforward manner.   Not only can time be wasted but it is quite possible to end up with an image that “looks” right to most people but which in fact has done something inexcusable such as altering the very precise color of a corporate logo.

One way to reduce the potential fo such confusion is to incorporate a color chart in shot.  Various types exist, including Gretag Macbeth (GM) and Chroma Du Monde (CDM).  The GM card, while primarily targeted at photography, is also in widespread use for video.   That chart consists of a matrix of colored squares, one row of which represents (steps on) a grey-scale.  It also includes some near-primary colours and some approximate skin colours of a few types.  The simplest use of such a chart would be to use the grey-scale row for white balancing and the other colours for “by eye” grading/tweaking.  The more experienced will probably make use of vectorscopes etc. but that can still be a nuisanceful if not cumbersome process.

Enter Matt Roberts’ Automatic Color Corrector.  We tried it out on some footage from his own Canon 7D and from my Sony EX3, the latter fitted with a slightly green-tinted infra-red filter, on a snowy day.  We even tried it on an image (featuring such a chart, as well as a model with lots of fleshtones) on Canon’s website ?URL? for their C300 camcorder.  In all cases, the correction was achieved in seconds.  We were particularly confused as to why Canon’s web-image image was so off-colour, but it certainly was, and the Corrector fixed it.

Once again, the link:

Adobe Production Premium CS5.5 – Orientation

Saturday, January 28th, 2012


  • What should and does it consist of?
    • Including anything non-obvious e.g. “tucked away”, “additional Downloads”, “obscure” etc.
  • ???

Answers (as far as I can tell…):

  •  _Support & Communities
    • Looks at first sight like any application’s Help dialog, but on deeper inspection is also connected web-wise and answers to questions are not restricted to Adobe products.
  • After Effects
    • In contrast to Premiere, which is for conventional light-touch editing, this is for heavier effects and compositing etc.
      • …AE is a “2.5d” application. The worldspace is 3d, but any imagery you have (discounting 3rd party applications such as Invigorator and such) is “flat”.
        • (As opposed to 3D Modelling apps such as 3dsMax, Blender)
  • After Effects Render Engine
    • Render farm: Network rendering with watch folders and render engines.
    • Previously, it was possible to install render engines on as many machines as wished, but not so under CS5.5, where a separate serial number must be obtained for each machine.  For small guys like me that makes it pretty useless.   It seems likely that a more flexible option will exist in future versions.
  • Audition
    • Audio editor, derived (many years ago) from CoolEdit.
  • Bridge
    • A combination of media file manager, media manager, metadata editor, also does some kinds of media processing.
    • Can be run standalone or from within apps e.g. Premiere: [File > Browse in Bridge…]
  • Color Finesse
    • A multi-host (including Premiere & AE) plugin that goes above and beyond typical NLE color correction.
    • On my system it only appears to be available under AE.
  • Device Central
    • Simulates media appearance etc. on a range of devices such as cellphones.
  • DigiEffects FreeForm
    • Manipulate a flat object into almost any shape using displacement maps and meshes in 3D space.
    • Examples: flowing cloth, animated loose filmstrips, rippling fluids, terrain flyovers, welded metal, morphs, reveals.
  • Encore
    • DVD authoring.  Menus can be created in Photoshop (using special layering techniques).
  • Extension Manager
    • Manage extensions (broadly like plugins) associated with various Adobe programs.
  • ExtendScript Toolkit:
    • Adobe workflow command-script editor
    • An IDE (along the lines of Visual Studio) for scripts in Adobe Bridge, itself serving to automate workflows involving multiple Adobe applications.
  • Flash Professional
    • A multimedia authoring program to create content for Flash-enabled platforms/devices.
  • Flash Catalyst
    • A designers’ tool for creating the user interface for Rich Internet Applications.  Primary function of being a GUI composer for Adobe Flex components.
    • Can import Photoshop, Illustrator, Fireworks, or Flash XML Graphics (FXG) files.
  • Help
    • A help resource not only with local help-documentation but also capable of searching beyond, even beyond Adobe, to find solutions.
  • Illustrator
    • Vector graphics editor e.g. useful for typesetting and logo graphics design. It is the companion product of Photoshop.
  • KeyLight
    • An advanced chroma-keyer, tackling reflections, semi-transparent areas and hair.
  • Media Encoder
    • Encodes audio and video media content.
  • Mocha
    • <<Stand-alone tracking and roto tool to help solve problematic shots challenging the built in tools of After Effects and Final Cut by bringing advanced planar tracking and matte creation tools>>
      • Planar tracking
        • Track a plane(-ish) surface in 3D space e.g. as it translates, rotates, perspective changes.
          • Typically more robust and capable than points-tracking.
          • Great for moving subject or tracking camera.
          • Overkill when the only (relative) motion is due to camera pan/tilt.
    • e.g. select an area then it uses any detail there including texture to get a fix, and follows changes in translation, rotation, perspective etc.
  • OnLocation
    • Direct to disk recorder / logger also acting as monitor with waveform monitor and vectorscope.  And no doubt much else.
  • PhotoShop
    • Such a big noun that it became a verb…
  • Premiere Pro
    • Primary editing app, with emphasis on productive cutting and smooth playback etc., minimising the need to render, leaving heavy effects and compositing etc. to AE.
  • Story
    • A collaborative script development tool/service. There is an application for working alone on an offline version and a web-based service where you can sync up with an online version.
  • Ultra
    • Vector-keyer (simple-to-use effective chroma-keying) that was once a standalone app by Serious Magic, now available as a plugin within Premiere (but not AE).  I get the impression it is regarded (or at least branded) as simple to use but ultimately less sophisticated/capable than KeyLight (???).
    • Serious Magic used to highlight its capabilities regarding reflections, semi-transparent areas and hair…
  • Utilities
    • ExtendScript
      • An integrated development environment (IDE) for the creation and debugging of JavaScript code for Adobe Bridge, to facilitate workflow-enhancing automation of tasks between elements of Creative Suite.
    • PixelBlender
      • A simplifying basis for implementing image processing algorithms (filters or effects) in a hardware-independent manner, taking advantage of parallel processing / GPU etc.
      • Downside to commercial developers is that code using it may be more visible / understandable.

Colorista Free

Thursday, December 1st, 2011

…and a one or two other free downloads from Red Giant

DaVinci Resolve (Lite)

Sunday, November 27th, 2011

I heard about and saw DaVinci Resolve in action on Den Lennie’s music video course/experience.  As a result I looked it up on the web and discovered there was a free version.  At that time the free version was limited to only a couple of nodes depth (I think) but was still useful.  Since then DaVinci have released a new version (8.1.1) without that restriction.  Confusingly, back in October I downloaded “version 8.1.1” with patches and also “version 8.1.2”.  Something got out of step somewhere!  But for ease-of-life, I will stick with their latest download, described as “version 8.1.1”.

I downloaded a copy of DaVinci Resol;ve Lite 8.1.1 to my MacBook Pro (MBP)  I went to then selected (in this order): [Host=MacOS], [Product Series=DaVinci Resolve], [Product=DaVinci Resolve Lite].  That gave a page prompting for user info (e.g. contact details)which I duly filled.  After that I was taken to the download page.

Resolve Lite runs on Mac OS but not (yet?) Windows (though that might follow eventually, according to My MBP has 8GB RAM and a both an Nvidia “9600M” (on motherboard) and a “9600M GT” (faster separate GPU).

My initial attempt to run Resolve Lite on my MBP resulted in a “whinge-window” about my machine’s GPU not being up tp Resolve’s requirements.  That turned out to be because in the Mac OS Preferences, Energy-Saving mode, I had selected “extend battery life” (or whatever) instead of “max performance” (or whatever).  This selection disabled the “GT” GPU leaving the machine to drop back to the lower-powered motherboard GPU.  Selecting “Performance” mode (and rebooting) fixed the problem – no more “whinge-window”.

The Resolve Lite application filled the whole screen, with none of the usual “three colour buttons” at top-left corner, merely the ability to respond (appropriately) to Command-H (Hide).  The initial screen was some kind of “User Logon” screen with default users Admin and Guest.  I double-clicked on Guest and was greeted by an instruction that I should first set Resolve’s Preferences.  Not unreasonably, it wanted to know which volume to use as Media Volume (for renders etc.).  I chose the HFS+ partition of my GRaid Mini drive, connected via FireWire (FW800).  In fact I created and selected a folder: [/Volumes/GRm HFS+/_App_Specific/DaVinci_Resolve].

Next I looked for some Tutorial videos:

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)


Avid Color Correction User’s Guide

Thursday, September 8th, 2011

  • Extremely useful

Cineform FirstLight: Explanatory & Instructional Links

Saturday, August 20th, 2011


  • The main principle is great – the decoder part of the Cineform Neo codec has to do levels-mapping work etc. anyway as part of its normal function, and so getting it to do the grading at the same time just means altering its scaling factors etc., which in principle means using less CPU as compared to the grading being done in the NLE (post-decode).   Also fewer successive quantizations (hence better overall visual quality).  You can specify different sets of factors (hence grades) for different video files. There are also some “Movie Looks” presets.
  • Additionally it gives the ability to split the grading process off to another person (as the tutorial videos show) – a great extra bonus. By using DropBox (say) the two (or more) of you can work in parallel at remote locations, grading-updates appear automatically on the remote NLE. Essentially only a tiny shared grading project file is saved in DropBox, no need to exchange actual video files.

I’m currently trying it out on a client project (non-critical) in Sony Vegas.  I will post my experiences from this separately.

Sony Vegas: “Movie Looks” via FX Presets or Cineform-FirstLight

Wednesday, August 17th, 2011

Sony Vegas allows chains of effects (“FX”) to be built up, which can optionally be exported or imported as FX Presets.  Some generous people on the web have offered their own FX Presets to achieve “Movie Looks” (dramatic looks) of various kinds.  These are more about emphasizing different kinds of mood than achieving clinically pure or film-grainy image quality.  Further details below…


Avid MC: Hi-Res Workflow & Color Guide

Saturday, August 13th, 2011

Cineform – Tutorials, Information & Tips

Thursday, August 11th, 2011


  • Best quality level to use for grading is FilmScan1.
    • The next one down, High, is only for final product, as intermediate totranscode from.
    • The next level up, FilmScan2, is “overkill”.
  • Tech Blog (many subjects)
  • HDLink
  • Firstlight
    • Does more than I imagined!
      • Has translation/projection adjustments (e.g. frame, zoom, pan)
      • It has “looks” (via LUT’s) e.g. “Bleach Bypass”.  Can scroll through them (e.g. via up/down arrow keys)
      • Can be keyframed hence dynamically changing (e.g. a pan to follow a moving object or adjust level/hue as sun sinks).
      • Can copy & paste attributes between different clips (select-all>Paste to make all clips have the same style)
      • Can “branch” projects to provide a dropdown-selectable menu of alternative grades/looks.
      • Great suggestions for incorporation in workflow:
        • While one person is editing, another can be grading.
        • Tip: store FirstLight projectsin DropBox folders, then everyonbe sees same instant-updates (e.g. extra alternative styles).
      • Possible there exists a problem when used with Avid Media Composer 5.5.2 (at least).
      • Conjecture: (if) First Light … is OpenGL accelerated when dealing with Cineform media (then) when it is handed to to other applications, the playback and processing of the LUT (metadata) is all CPU, thus causing a performance discrepency.
  • Vimeo: Cineform Examples & Tutorials & Groups:

DaVinci Resolve Lite – free

Thursday, April 14th, 2011

DaVinci Resolve Lite – free:

The full version has 3D tracking “Power Windows”, so you don’t have to manually generate and track masks.  It is said by some to be runnable on linux.

Avid Media Composer – Secondary Color Correction – via Plug-ins

Saturday, March 5th, 2011

Although Avid Media Composer (MC) itself has no native Secondary Color Correction, that functionality can be achieved via plug-ins such as Boris (e.g. BCC Colors & Blurs) or Spectra Mate.

Gamma in Camera – Pros & Cons & Bits

Sunday, February 20th, 2011

To obtain/maintain/increase/verify an intuitive feel and hence greater confidence for the appropriate use of gamma in camera settings, I did some thinking & research.  The basic idea is as follows:

  • A typical consumer camcorder produces crisp images
  • “Film Look” use of a professional camera may employ non-standard gamma settings in the camera settings.
  • The straight results of this are images of “washed-out” appearance.  To obtain a pleasing result requires grading (levels & gamma, saturation, color curves etc.).  Example:

Regarding the second, more professional approach:

  • The immediate result is “scary” because it looks washed-out
  • The goal is not to produce an immediately-pleasing image but to capture “as much information as possible” (an often-quoted phrase) from a scene, with the intention and indeed requirement for grading.  One has to see it “through the eyes of a grader”.  A naive person (e.g. a newbie or a client) will of course not immediately see it that way.
    • Example references to this:
        • <<The RED RAW look, the washed out, flat, low contrast, incredibly versatile form in which the footage originates … screams possibility in our faces. Low contrast can, to the DP, imply power … being precious with the RED footage, and trying hard to save every bit of detail we started with.>>
        • <<I can see how the washed out look can become something in and of itself, and have people like it, and others not.>>
  • What does this mean?  In general, possibly:
    • The complete levels and color space of that scene, un-clipped (clipping destroys information).
    • Any subtle light/shade within shadows of the scene.
  • Questionable aspects:
    • Grading takes time (bad for quick-turnaround jobs) and if written to intermediate files (e.g. prior to editing) then it can also eat disk space.
    • There is a trade-off between generality and specificness.
      • Capturing maximum information provides the grader with greatest freedom.
      • On the other hand if it is known in advance that crushed shadows are required, e.g. to obtain silhouettes / film noir effects, then it is a waste of effort / bits if not counter-productive to boost them in the camera.
    • The degree to which grading can be applied in practice depends on the levels and color space resolution of the camera.
      • Prosumer cameras such as Z1 or XDCAM-EX record to 8-bit levels resolution.   And then only a sub-part of that levels-space (typically 16..255 or 16..235, depending on camera and settings).
        • For cameras whose sensors work at greater resolution (and can output this information) there is the option to record to external devices at that greater resolution (e.g. 10 bits 4:2:2).
      • While it is possible to apply effects like levels, gamma or color-curves (S-curves) to “professional” washed-out imagery, beyond a certain degree, the image will appear ragged or flesh-tones will appear sunburn etc., as the gaps between successive values of the bit-space get stretched too big.  One can actually see the gaps (between striations) in a Waveform Monitor (applied to the result of grading).
        • In that case we have in fact lost information, defeating the original goal…
      • If the results of grading are pretty-much identical (or, from the previous point, possibly inferior) to what would have been obtained in-camera using a more standard setting, then what was the point?
  • Reassessment:
    • Due to the trade-off issues, the real goal should be to record the maximum relevant information.   In other words, to be a little bit specialised.
      • This is the logic behind employing physical filters on a camera, such as grad filters (“sunglasses” e.g. for the upper – sky – part of the image).
      • Even on feature movie sets I have come across formal instructions for film cameras to be deliberately “pushed a stop or two”.  Committing at record-time to something that could, presumably, have been achieved equally-well in post, which itself can be done almost immediately based on HD footage recorded simultaneously from HD cameras attached to the main camera.  I have seen directors receive rushes and quick cuts from such cameras within seconds…
    • The degree of commitment/specialization may depend on the type or uncertainty of the scene and on the consequence of making a mistake.  Feature films are very planned and their shooting is very iterative.  On the other hand there can be one-offs such as special-effects or VIP moments.  At the other extreme may be live events where anything can  happen – subjects, lighting, over-bright/over-dark etc.
    • The missing factors in the “maximum information” principle are then:
      • Relevance – what kinds of information are relevant?
      • Resolution limitations.
        • If we only have 8 bits, then what is the practical limit of grading?
        • Conversely, if we need to maintain maximum latitude etc., when do we need more than 8 bits (in practice mostly 10 bits)?

Cineform Settings – which ones to use for what

Thursday, December 23rd, 2010

Which modes of Cineform are appropriate under which circumstances:

  • Paraphrased from [, as of 2010-12-23]
    • NeoScene and NeoHD uses can select 4:2:2 in any quality.
    • High quality is for finished material (e.g. to be output to DVD/BluRay) but if further grading is a possibility then use Filmscan 1
      • Filmscan 2 is overkill.
    • Neo4K and Neo3D users also get 4:4:4 and 4:4:4:4 support.
      • Requesting these modes with (other variants of the software?) will result in a watermark.
      • For extensive post, filmscan and 4:4:4 is probably a benefit.
      • 4:4:4:4 requires lots of power and raid arrays.
    • The uncompressed mode should generally be avoided – it is only intended for camera acquisition to save battery power.

Cineform is a codec for digital intermediates.  When used in appropriate ways, it offers visually lossless compression/decompression.  Some quality reduction does occur but only to a degree that is not important to (or even noticeable by) most people’s eyes, even after several rounds of compression/recompression.  In contrast, delivery formats such as DV, DVD, XDCAM-EX are suitable only for a single round of compression/decompression, and even then are lossy (lose quality) to a degree that many people can notice, especially when playback is paused at a single frame.

XDCAM-EX Gamma Settings

Monday, August 30th, 2010

I worried about and noticed in practice an effect where if I was using CINE gammas on the XDCAM-EX and exposed for faces at 70% (by zebras) then the gamma rolloff would result in “pasty-face” appearance.  It does …and did…  The solution for good looking faces is one of the following:

  • Under-expose in shoot, raise in post.
  • proper-expose in shoot, use standard gamma (not cine gamma), be careful not to let the face hit the knee (?) e.g. set knee to 90% or 95%.
  •  take a given gamma curve (or even a flat standard one) and tweak it using gamma level & black-stretch adjustments etc. until it fits the scene.


FCP inherent (unwanted) level & gamma changes – unlike Avid’s AMA

Monday, August 30th, 2010

Someone noticed that XDCAM-EX footage imported to FCP appeared different as compared to Avid (AMA import).  Addressed in an Avid forum thread started May 2010, referring to FCP 6.06 and Avid 4.02:

  • What AMA gives is, is _exactly_ what the camera has captured. What FCP shows you, is a remapped image, most often with a gamma shift. 
    • (For Avid AMA imports, Avid settings for RGB or 601 etc. make no difference – it’s always as-recorded).
    • … imports (to FCP) will look different (to expected), because FCP/QT “corrects” the gamma when bringing in footage (even if you would not want that).
  • Most people seem to agree that FCP works in 0-235, not 0-255, not 16-235. And without the option to leave things untouched. So if you import something into FCP, there’s no getting it back to the original levels anymore.

I guess I’d better do some experiments with ramps & scopes etc…

FCP Grading Filters – Desaturation & Levels (non-intuitive but useful)

Friday, February 19th, 2010

The real image manipulation happens with the desaturation and level filters. Desaturation affects the richness of colors and level (via a un-intutive set of controls) will adjust the black point, white point and distribution of brightness across the whole image. The settings of these filters will depend on the scene and the camera you have.Set Desaturate to -50. This will boost the colors just a tad. Adjust to taste. Set the level controls as follows: input = 0 input tolerance = 100 gamma = 1 output = 50 ouput tolerance = 80 Ken Stone agrees the Levels filter is non intuitive:[ ] <<< The Levels filter is supposed to be a more advanced version of the Brightness/Contrast filter, offering separate controls over highlight, midtone and shadow areas. In addition this filter offers the choice of working the image in RGB mode or any one color channel independently, Red, Green or Blue.However this filter is poorly implemented and is clumsy at best. It has five slider controls; input, Input Tolerance are used to lighten the image. The Gamma slider controls the midtone areas and Output and Output Tolerance used to darken the image. What makes this filter so difficult to understand and use is the fact that the filter opens with the default settings of the Input Tolerance and Output Tolerances sliders set at 100. With these two settings at 100 neither the Input Slider nor Output sliders work. It is necessary to lower either the Input or Output Tolerance sliders then start adjusting the Input or Output sliders. The real problem is that the highlight and shadow areas have two sliders each for control. Photoshop has a Levels filter but it is a different animal. Levels in Photoshop also has a ‘Histogram’ which gives a graphic display of all the pixels in the image based on their brightness values. The ‘Histogram’ display is essential to setting levels but the Levels filter in FCP has no ‘Histogram’. To be honest the Levels filter in FCP does not work for me at all – I just don’t get it. The Proc Amp filter does basically the same thing and works well. If you want to play with this filter I suggest that you set either Input or Output to a setting of 20 then start lowering the Tolerance filter down from 100. As you lower the Tolerance settings more effect will be applied. If anyone can offer any insight into this filter I would love to hear about it. >>> 

FCP Levels & Gamma Conventions e.g. for Stills

Friday, February 19th, 2010

Things To Remember []

  • Still images are RGB in a 0 to 255 range
  • Levels above 100% FCP, 100 IRE or code 235 are called “super white”
  • Final Cut Pro automatically converts images to fit into the 0% FCP to 100% FCP range when it is set to “White”.
  • Final Cut Pro automatically converts images to fit into the 0% FCP to 100% FCP range when it is set to “Super White”.
  • Final Cut Pro only looks at the 0% FCP to 100% FCP range upon still image export, and maps this range to 0 to 255 RGB.
  • Picture information can be lost on still image export if you have picture information in the 100% FCP to 110% FCP range.
  • Final Cut Pro always applies a gamma correction of about 0.8 to imported still images. If necessary, this can be corrected by applying a gamma correction of 1.2 in Final Cut Pro or 0.8 in Photoshop.
  • Don’t preempt Final Cut Pro’s conversion of still images by setting your blacks in Photoshop to 16 and whites to 235. Final Cut Pro expects you to use the full 0 to 255 RGB range.
  • “White” and “super white” settings only effect the import of still images.
  • “White” and “super white” settings do not effect video or video rendering.

FCP Grading Filters

Friday, February 19th, 2010