I am editing a video and have added a black and white filter, but a specific part is masked out so that it is still shown in colour. This mask was very time consuming to create for each frame and as such I do not want to have to re-do it. I want to slow down the video clip so that it takes place over 6 seconds instead of 2 seconds.
My question is: Can I slow down this video clip while still keeping the effects applied correctly?
If you take the black and white comp and drag it into a new comp you can stretch the time of the whole comp from there.
If you right click on the bar in the layer panel that says things like "|Mode| TrkMat| Parent & Link|" you'll get an option to show a category called "Stretch." Once you show that column you'll see a blue 100.0% and you can drag that to slow down your black and white comp layer.