addressed Video effects - start & stop

[St Bosse]

How does one terminate a video effect?

I have a clip that I want to start with a "spotlight", about a 1/4 screen in one corner, then grows to half and then to full screen. This happens in about 10 seconds at the beginning of a 2 minute clip. 
Question: How do I terminate the "spotlight effect" after 10 seconds into the 2 minute clip? The same question would also apply should I want to start a "spotlight effect", say about 90 seconds into the clip, active to the end?

I think the same question could apply to various other effects.

St B

[borate]

Split the video where you want the effect to begin and end.  That creates a new clip to which an effect can be applied.

To fade the spotlight on/off animate the OPACITY slider...

Start with a zero opacity keyframe.  Slightly later program a 100% keyframe.  Do the opposite at the end of the clip.

Or apply a CROSSFADE transition at the start and end of the clip.

[St Bosse]

..mmm. . . I was wondering about that. The fundamental rule here or the secret sits in the "splitting of the clip". All effects are applied to the full length of a clip! cannot be done on portion of a clip. I.e., the effect will only terminate when the clip ends?

Thanks

St B

 

[borate]

Keyframes can decide where an effect starts or ends within a clip.

The above example could have just as easily looked like this... 

Now, the effect appears after the start of the clip and disappears prior to the end, for this result...

First and second keyframes are zero opacity.  Third and fourth are 100%.  Fifth is zero.

[St Bosse]

Aha! I see. This should sort my problem. Thanks

St B