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This tutorial will help you quickly learn how to color correct your videos. It will cover monitoring, superwhites, color curves, white balance, proper levels, and more.
To start, you should make sure that you are monitoring your signal correctly.
An important note to keep in mind is that you may need to manually wrangle your video levels for Sony Vegas to ensure that they are correct. For simplicity's sake (since this is a crash course), I'll assume that you are working with in an 8-bit Vegas project. 32-bit projects, introduced in Vegas 8, introduces a new set of issues; information in this article does NOT apply to 32-bit projects (see the article on Vegas 8 color space for more information).
To monitor your video accurately, two of the choices area:
For external monitors, see these instructions for calibrating a broadcast monitor.
Computer monitors hooked up via DVI do not need calibration of the interface, unlike external monitors hooked up via analog interfaces such as composite or S-Video. VGA monitors should also be calibrated.
Nearly all cameras will record values above digital white level. I refer to such values as 'superwhites'. Superwhites are illegal values that are higher/brighter than the maximum white allowed. They will usually (though not always) be clipped in the end viewer's signal chain. This clipping can occur at the monitor (e.g. if it's a LCD) or at the DVD player. All broadcasters will clip superwhites prior to broadcast.
The problem with superwhites is that you may be looking at detail that will later be clipped and your audience won't see. This can happen if you are monitoring on a CRT external monitor as described above. We can avoid this by making sure we do not produce any superwhites after color correction.
A good place to start is by using a Color Curves preset that clips superwhite values right off the bat. You'll need to download this .veg containing my color curves FX and save these color curves as presets. Do this now.
Apply the first color curves to your clip. This is a good starting point of any color correction. Note that this color curve clips off any superwhites and addresses that issue. It will also clip off values below black level. The latter behaviour doesn't hurt as values significantly below black can cause some older TVs to confuse the 'superblack' with sync and cause the picture to roll.
Drag select the two points indicated in the diagram below. Use the left and right arrow keys on your keyboard to move these points left/right. Moving the points to the left will increase exposure and make the image brighter. Moving the point to the right will do the opposite.
If you wish to map all the superwhites into legal range, you can simply hit the Delete key to delete the two points shown in the diagram below (assuming you are using the first color curves preset contained in the .veg file). This will map superwhites into the legal range instead of clipping them. Or, you can start with the second Color Curves preset contained in the .veg.
Note that when you move the points left/right, you will cause the curve to take on a mild s curve (or inverted s curve). A s-shaped curve will increase contrast and vice versa. Usually, most videos will benefit from a slightly boost to contrast. You should further adjust the curve to your liking by grabbing the handles (the square boxes on the end of the lines) and manipulating the shape of the curve as shown below.
Note that increasing contrast via Color Curves has a tendency to de-saturate highlights. You can use the Secondary Color Corrector preset in the .veg and play around with the saturation slider to counteract this effect.
There are multiple ways of fixing white balance in Sony Vegas... this is my preferred method. To fix white balance in shots, use the 3-Way Color Corrector FX. The diagram above shows the complementary color eyedroppers. Start with the eyedropper on the right. Click the button, and then drag-select an area of the image that should be grey or white. Pick areas that are grey or white in real life.
Next, do the same for the middle (midtone) complementary color eyedropper.
You may find that the highlights still have a color cast to them. To fix this, add the Secondary Color Corrector and use settings similar to the ones shown below. Set saturation to some low value, and use the "Limit luminance" settings to affect only the highlights. Be careful not to de-saturate highlights that should otherwise have color to them.
Results of this method are shown below.
 Before. |
 After. |
Remember than in Vegas, sometimes you need to manually wrangle all your levels. If you are outputting to a video format like DV, HDV, MPEG2 then you don't need to do anything. (That is, assuming you are using the default Vegas codecs).
If you are outputting for computer formats like still image formats (JPEG, PNG, GIF, etc.) or computer video formats (most streaming formats, Windows Media Player, etc.) then you will need to manually perform a color space / levels conversion. I would nest your .veg project into a new project and apply the "studio RGB to computer RGB" Color Corrector preset. The reason I advocate nesting is so you don't accidentally render this levels conversion when you don't mean to. Applying this FX at the track or video preview level is dangerous when you forget to disable it when rendering to a new track.
Camera matching tutorial.
How to read the Waveform monitor and use the levels filter.
There are also more Sony Vegas articles on this site in the articles section.
This site by Glenn Chan. Please email any comments
or questions to glennchan /at/ gmail.com
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