Editing a Filter
As you can see from the previous tasks, actually adding a filter is relatively easy. The creative fun starts when you want to alter the wide range of parameters that come with each filter, hopefully with the aim of creating something unique. This is called editing with keyframes . Keyframes are explained in more depth in the "Chapter 8. In fact, many of filters have similar names and similar parameters.To create your own custom-made filter, you need to open the editor and then scrub through the Source Viewer Timeline deciding where and when to alter the various parameters.To understand filters, you need to experiment with them; because of their many complex parameters, it's impossible to show everything in the pages of a book. You need to see every living variation on the screen; otherwise you'll never know what sort of highly original effects you can create just by tweaking one underused parameter.
To open the Filter Editor
With a filter present on a clip, do one of the following:
- Figure 9.30 ).
- Double-click the purple line running across the top of a clip and select a filter from the menu that appears (Figure 9.31 ).
Figure 9.31. …double-click the purple line at the top of the clip…
[View full size image] - Right-click the purple line running across the top of a clip and select Edit from the menu that appears (Figure 9.32 ).
Any of these methods brings up the Filter Editor (Figure 9.33 ).Figure 9.32. ...or right-click the purple line and select Edit.
Figure 9.33. The RT Filter Editor interface.
[View full size image]
Figure 9.30. Open a filter by clicking the Filter icon or…

- Place the mouse cursor over any of the parameter boxes and wait for a double-headed cursor to appear (Figure 9.36 ). Hold down the mouse button and drag to the right to increase the value displayed. Drag back to the left to reduce the value displayed.
Figure 9.36. Work with the double-headed arrow…
- Double-click inside the display area and enter the numerical value you need; then press Enter (Figure 9.37 ).
Figure 9.37. …or enter the number directly.
- Click inside the parameter curve area on the line color that represents the parameter you wish to alter. Parameter lines and boxes always match up with coloring, but the line only appears if the parameter box is open, or if the parameter was previously adjusted (Figure 9.38 ).
Figure 9.38. You can add and manipulate keyframes inside the parameter curve area.
- RT filters can be played inside the editor to see how your keyframes have affected the final image. If it's a Classic filter, you can only scrub through the image. To play a Classic filter, you must first exit the editor and allow the filter to render.
- To return the Classic slider to the default value, click the small button that appears on the right side of the slider once a parameter has been altered (Figure 9.40 ).
Figure 9.40. To reset a slider, click the small button next to the numbers.
- You can increase the size of any editor window by clicking the Maximum Inlay Size button
on the Liquid Edition toolbar.
KeyframesWhen you adjust the parameters in the Filter Editor, a small gray diamond appears on the editor's Timeline (Figure 9.34 ). These diamond marks are keyframes and they are part of the magic behind the NLE system. Figure 9.34. Keyframes on the Timeline of the Filter Editor.![]() |
To edit a filter
1. | Open the Filters Editor using one of the methods detailed in the "To open the Filter Editor" task earlier in this chapter. |
2. | Open the parameter you wish to alter by clicking once on the small triangle to the left of the name (Figure 9.35 ).Figure 9.35. Opening a parameter area.![]() |
3. | If this is an RT filter, you see various colored boxes and you can alter the parameters in the following ways: |
If you are using a Classic filter, you can adjust the parameters using sliders or by entering numbers directly into the boxes at the end of the slider controls (Figure 9.39 ).
Figure 9.39. Classic editors used simpler sliders.

Applying a ParameterIf you need to apply any parameter to the whole length of a filterfor example, using Mirror to flip an imagethen drag the Keyframe symbol from the parameters label area into the preview screen of the editor. Those settings in the parameter box then apply to the whole filter (Figure 9.41 ). Figure 9.41. Applying a keyframe across the duration of a clip.[View full size image] ![]() Figure 9.42. Applying a keyframe to an individual keyframe.[View full size image] ![]() |