Apple Shake 4 Tutorials - Manual (Page 246)

246 Tutorial 9 Creating Clean Plates
9 Turn on the matchIllum option to fix the color match between images.
Now you should have a fairly good background plate. Notice that Shake arranged and
stitched the images correctly, even though they were not connected in the order that
they should appear in the panorama.
This is possible because there is enough overlap between the images (about 20 to 30
percent) to allow accurate calculation and positioning.
Also notice that two of the images are distorted to conform to the “locked” image,
photo1369, represented by the red border in the above illustration.