Why RAW and LOG Recording Are So Important

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This post is a series of notes I made during one of my NAB sessions back in April. This particular class, taught by Robbie Carmen, centered on both RAW and LOG recording; the definitions of each, the differences between the two, reasons why you should shoot in either format, things to consider when shooting RAW or LOG, production and post-production workflows, and some general guildelines.

Regular Video

  • Parameters are baked into the signal (white balance, exposure, color space, codec, etc.)
  • Easy to use
  • Limiting for maximum flexibility in postproduction

Why Should You Care?

  • You want the best looking image possible
  • It's all about capturing a ton of information and giving you the most flexibility in post
  • Capturing the most dynamic range

What RAW Recording Gives You

  • You can avoid sensor processing
  • Ability to change any exposure/color parameters on the fly
  • Avoid the pitfalls of regular video

Workflow Thoughts

  • Shooting RAW and LOG can complicate on set workflow
  • There's a need to normalize content for on set viewing (Remember that RAW and LOG will look extremely flat coming directly off the camera, which can confuse clients who are unfamiliar with the format.)
  • Potentially the need for additional on set personnel
  • Potentially the need for capable monitoring equipment
  • High capacity, fast storage is needed

DIT

  • A DIT manages data and workflow while on set.
  • Develops LUTs (Look Up Tables) and uses them
  • Potentially implements hardware
  • Potentially color corrects and grades while on set

The Onset Colorist

  • Grades from camera transfers on set
  • Grades live from the camera feed
  • First line of defense in processing footage - a) grades that can transfer to post, b) creates an initial look setting

Onset Viewing

  • Proper monitoring for LOG footage is essential
  • Many monitors are capable of supporting LUTs directly

RAW and LOG Are Not The Same

  • Logarithmic recording is a way of capturing an extended dynamic range in a scene
  • Multiple LOG curves exist for different manufacturers
  • Gamma is converted in post-production
  • RAW recording bypasses the sensor processing decisions, so nothing is baked in

RAW

  • RAW is not video. It's information; data
  • Color is produced on most cameras by filtering each pixel to produce RGB
  • The pattern of this filtering is called a Bayer Pattern which most cameras use
  • RAW data is in this array
  • Patterns differ, depending on the camera
  • All footage must be debayered in order to view it.
  • Not all RAW is created equal
  • RAW data is often compressed, some cameras more than others
  • Bit depths can range from 12-16 bits depending on the camera
  • 16 bit RAW is not the same fidelity as 16 bit LOG
  • RAW bit depth does not apply well to the way we view images
  • While processing RAW you can often place it into the color space of your choosing and assign a gamma curve
  • Develop RAW to a starting point where you have the greatest flexibility in grading. Don't use RAW control as a principle form of grading.

LOG

  • LOG is processed footage
  • LOG is a particular type of Gamma curve
  • Manufacturers have their own flavor of LOG
  • Don't confuse "flat" with LOG
  • Shooting with reduced contrast, saturation and sharpness can help but it's not LOG recording
  • Many cameras try to approximate LOG recording

LUTs

  • LUTs have been the source of a lot of confusion
  • It transforms data into a specific color space
  • Technical LUT - the LUT you would put on a monitor
  • Creative LUT - a look or grade that a colorist can save and then be applied to any footage
  • Output LUT - profile a film stock, place it into your system so your grade matches the film stock you will output to.

You don't have to go to a LUT right away when bringing in the footage to your NLE. Just simply grade it when you drop it in. You don't have to drop a LUT on it. First, adjust the curves with a waveform monitor and then bump up the master saturation.

If you have anything to add from your experiences in shooting either LOG or RAW, feel free to leave your thoughts in the Comments section.