Getting Started with Nuke - Nuke 101: Professional Compositing and Visual Effects - page 24

To view the different inputs of a viewer, hover the mouse pointer over the Viewer
itself and press the corresponding numbers on the keyboard.
3. Hover your mouse pointer over the Viewer and press 1 and 2 several times. See
how the images change from one input to another.
Using this method you can keep monitoring different stages of your composite as
you are working. This is also a good way to compare two images.
Playing a clip in the Viewer
Playingaclipiskindofmandatory inacompositing package. Let'sseethispiece ofmov-
ing image playing in realtime.
This notion of realtime is very subjective in relation to the specific footage you are using.
For film, realtime is 24fps (frames per second). For PAL video, it's 25fps. For some other
purpose it might be 100fps. Some computers will simply never be able to play realtime
footage of some resolutions and frame rates simply because they are too slow, no matter
what tricks you try to apply to them.
Thisaside,youcanstrivetoplayclipsinrealtime.First,youcanattempttoplayfootagein
theVieweritself.Youwillneedtodefinewhatrealtimeisforyourfootage.Thisfootageis
25fps. Let's set the Viewer to 25fps. You do this in the fps field above the Timebar. When
playing, this field will show how fast playback really is instead of how fast it is supposed
to be playing.
1. Set the Viewer fps field to 25 ( FIGURE 1.22 ).