Camera Tracking - Nuke 101: Professional Compositing and Visual Effects - page 423

You will leave the Focal Length Type at Unknown Constant. If the zoom was
working, you would have chosen Unknown Varying.
Because I know the camera make, I can easily find out what the Film Back Size
is. Doing a quick Wikipedia search shows that this camera has a ⅓-inch sensor,
which is 4.8mm × 3.6mm. Use this information for the Film Back Size.
2. Set the Film Back Size property to X = 4.8, Y = 3.6 ( FIGURE 10.12 ) .
Figure 10.12. Changing the Film Back Size property.
This camera is handheld, so you will leave the Camera Motion property's drop-
down menu at the default of Free Camera.
3. Now go back to the CameraTracker tab and click the Solve Camera button.
Nuke is now processing the information and trying to re-create the real-world
situation out of the features it tracked. The Progress Bar indicates how long this
is taking.
It's done. Good for you ( FIGURE 10.13 ).
Figure 10.13. Solved tracks are green and red.
Asyoucansee,thetracks(features)changedcolorstorepresentthetracks'status.Amber,
asbefore,representsunsolvedtracks.Youcanseethatthemajorityofthetracksaregreen,