Thank you very much!
It's all been very helpfull and I'm sorry to ask so much, but...
My video becomes very bright, and in your video it explain how to avoid that with a picture, but not with a movie in my case, so how do I avoid it from becoming so bright?
Did you play with the blending modes as Rick said?
Next time just read the After Effects help! Everything about most effect is explained there: http://help.adobe.com/en_US/aftereffects/cs/using/WS09B6A698-8F9E-4a00 -8D1B-07FC62FB2D30a.html#WS3878526689cb91655866c1103a9d3c597-7a57a
Stan, if the image gets brighter, it means that the echoes are blent (or is it blended?) with the original image in a way such that the colors are added or at least not respected.
The last link I sent you explains ALL the details about the effect, so look at the "Echo Operator" part, described as "The blending operation used to combine the echoes".
From there on you just need to think about what a given blending mode will give you:
- Add and Maximum will necessarily brighten your image,
- Screen and Blend may also brighten it,
- Minimum won't obviously, but it also means that the echoes won't appear in dark regions of the image
- Composite in Back/Front will not affect the brightness of the image, but obviously composite in Front will be useless if you don't have an alpha channel since all the echoes will be placed "behind" your original video
If this doesn't help I can't do anything else.