Personal View FAQs Wiki

• Vegas Pro's working color space is RGB with a range of 0-255 in each of the R, G, and B channels.
• In 8-bit projects, RGB values are integers 0-255.
• In 32-bit projects, RGB values are 32-bit floating point values.
  • Floating point values are 0-1 internally, but Vegas maps them to 0-255 in most places in the user interface, so the distinction is moot for the user, and this FAQ will reference the full 0-255 range in all cases.
  • 32-bit projects support values below 0 and above 1, and some filters allow access to these out-of-range values.
  • Compositing operates with 32-bit floating point precision in 32-bit projects.
  • Filters and media generators with green icons operate with 32-bit floating point precision in 32-bit projects; filters and media generators with a blue icon support only 8-bit integer precision.
  • In 32-bit full range projects, you should set the compositing gamma to 2.22, which means that Vegas's compositing and filters operate linearly on the encoded RGB values, same as in 8-bit and 32-bit video levels projects. Setting the compositing gamma to 1 changes the behavior of compositing and some filters in a way that you probably don't want (but perhaps is appropriate for video sources with a linear transfer function).
• Projects can be switched freely between 8-bit mode and 32-bit video levels mode with no change in the behavior of compositing or filters. 8-bit mode is much faster for editing, preview, and rendering, whereas 32-bit mode is quite slow but much more accurate and less prone to banding and other color precision artifacts - especially the cumulative errors of long filter chains.
• By default Vegas Pro makes no particular assumptions about the primary chromaticities or transfer function (“gamma”) of the RGB encoding: operations are linear on the RGB values, and the scopes and preview window show the full range of RGB values with no conversion or remapping.

• Typically your source video and delivery formats will be rec.709-encoded, so ideally your monitor should be calibrated to display rec.709 video as well.
• Most computer monitors are calibrated for sRGB, which is very close to rec.709. They have the same primary chromaticites and white point. Rec.709's transfer function is approximately a power curve with a gamma of 2.4, compared to sRGB's transfer function which is a power function with a gamma of 2.2. The differences are small enough that you'll be fine to just calibrate your monitor for sRGB and ignore the differences - in fact the gamma would need to be changed by a larger amount than this small difference to account for different levels of ambient light in your editing environment.
• I suggest calibrating your monitor using the excellent Lagom LCD test pages, even if you use a CRT or other type of monitor.
  • You will mostly use the Contrast page.
    • Set your monitor's contrast adjustment to the maximum, and then adjust the monitor's brightness and the individual R, G, and B gain and bias settings.
    • Make black, grey, and white show no tint.
    • Make the black background as dark as possible while still showing even contrast across each of the color ramps. There should be a visible difference in brightness between the black background and the leftmost rectangle of each gradient. As much as possible, the changes in apparent brightness from each rectangle to the next should be equal at every position in each gradient and between the gradients.
  • Use the Black level and White saturation pages to fine tune the black level, white level, and color balance. There should be a visible difference between every level.
  • Use the Gamma calibration page to adjust the gamma. Aim for a gamma between 2.2 and 2.4. Most good monitors calibrated for sRGB will be right around 2.2 out of the box. If your monitor doesn't have a gamma adjustment, your video card driver might, but beware that it might have separate color adjustments for 2d, 3d, and video surfaces. It's best to not change the gamma if you don't have to. An adjustment of the monitor's brightness adjustment is usually all that's needed to account for different ambient light conditions in your editing environment.

• By default, most operations in Vegas use the full 0-255 range of RGB values regardless of the project settings:
  • preview window
  • compositing
  • filters
  • still image import
  • media generators
  • full-screen preview (unless you enable the Studio RGB option in prefs, which uses 16-235)
  • Vectorscope (unless the Studio RGB option is selected, which uses 16-235)
  • Waveform scope (unless the Studio RGB option is selected, which uses 16-235)
  • Histogram (the Studio RGB option has no effect. It seems to be a bug)
  • RGB Parade (the Studio RGB option has no effect. It seems to be a bug)

• Video input mapping to RGB level ranges, and video output mapping from RGB level ranges depends on the video format and the project setting. OOR means out-of-range preservation - that is, values above the channel's range maximum and below the range minimum are preserved (including superwhites and superblacks).

† In 32-bit full range projects, out-of-range value can be recovered or preserved by using a filter that reduces contrast or increases contrast.

‡ Quicktime h.264 and ProRes input boost the gamma by 1/0.88. Compensate by adding a Levels filter with 0.88 gamma at the beginning of the filter chain. Don't alter the input and output ranges in this first instance of the Levels filter - create a second instance after it if you need to adjust the levels ranges. It is a documented bug in Quicktime:

• So yes, Vegas's handling of RGB levels is totally inconsistent and non-standard. You'll need to do different things in your project depending on your input and output formats and preferences.
• A levels filter with the “Studio RGB to Computer RGB” preset expands RGB levels from 16-235 to 0-255.
• A Levels filter with the “Computer RGB to Studio RGB” preset compresses RGB levels from 0-255 to 16-235.
• Mapping from input format ranges and mapping to output format ranges depends on the format, and here Vegas seems to follow standards:
  • 8-bit YCbCr: Y=16-235, Cb=16-240, Cr=16-240
  • 10-bit YCbCr: Y=64-940, Cb=64-960, Cr=64-960
  • 8-bit RGB: R=0-255, G=0-255, B=0-255
• Quicktime .MOV input requires Quicktime to be installed. I use Quicktime Alternative 3.2.2.
• .AVI Cineform and .MOV Cineform are the only compressed 10-bit formats that Vegas can read with 10-bit precision, thank to integration with the Cineform SDK. Install the free GoPro Studio to enable reading of Cineform files. (version 2.0.0.285 tested)
• If Vegas is reading your input using the wrong YCbCr→RGB conversion matrix, you can compensate by using 601<->709 Channel Blend filter values at the beginning of your filter chain.