Importing Issues

[Hans Sieber]

Hi Arica,
what do you mean when you write “But after it imports, it turns into a Matte and the footage is black.” Do you have a real time matte effect after importing? If so you should check the ignore alpha box in your import options. Of course only if you dont need the alpha signal. You are sure that the QT is encoded in Avid DNXHD? If so then the import should work without problems.

Hans

[Arica West]

Thank you so much! That was the problem. Do you mind me asking, what is the alpha signal and when would I need it?

Thanks again,

Arica

[Hans Sieber]

Hi Arica,
normally you don`t have an alpha channel with raw material. If you digitise from tape for example theres no alpha. There are two ways of implementating the alpha channel in pictures. The first way is the delivery the alpha channel separately from your material. The second is premultiplication. Each title you create e.g. is a premult, which means that the picture is multiplied by the alpha matte.It`s a rather large field I´m touching here. An alpha channel is basically a black and white picture that represents the transparency information of your material. It can range from full white to grey to black. Each value represents if the picture is fully opaque or partially transparent or completely transparent. Each time you use the avid title tool avid creates an alpha matte for your title. Without it you will only see the title itself and not the picture beneath it. Just create a title drop it above a picture in your timeline and use the “delete Effect Button”. The picture below will no longer be visible. This is just one use of the alpha channel. Other examples would the animatte effect, any form of luma or chroma keying etc.
Hope I could shed some light on the issue for you. If not let me know.

Hans