|
10/12/2006
What is an Alpha Channel and how does it work with Edius?
Edius works with video clips and graphics that have an Alpha Channel automatically when those files are placed on the timeline.
In any file, whether it is video or a still graphic, there can be extra information embedded in the file that has a value of transparency. This is called an Alpha channel.
When a clip with an alpha channel is placed on the timeline, the area with the alpha channel will allow the video on the lower track to be seen.
One example of this is the Digital Juice lower and side thirds. When placed on the timeline the Digital Juice clip overlays over the top of the video underneath it. The reason it does this is because of the Alpha Channel that is embedded in the clip.
Another example is the titles that come from quick titler¡K the also use Alpha channel to overlay the titles over the video.
Now, the transitions in Edius do not support Alpha Channel so how do you dissolve in and out of a clip with Alpha?
If you look at any video track name you will see a small arrow just to the left. If you select the arrow you will expand the track so you can see the transparency rubber band.
Select the Mix button and you will be able to adjust the transparency level in the same way you work with the rubber bands when adjusting audio.
This is a very quick way to dissolve in and out of clips with Alpha.
Another way is working through the 3DPiP. The only thing to watch out for in 3DPiP is if you want to move the clip in 3D space you must make sure and turn off the light and shadow or you will end up with a weird surprise. ļ
You can move Alpha channel clips on and off the screen in a wide variety of ways using 3DPiP.
We are all hoping that one day Canopus will rework both the transitions and 3DPiP to work with Alpha more completely so that you will have a plethora of choices.
Mike Downey
|
|
|
