Negative Cutting: A/B Rolls, Cueing
An alternative to checkerboard assembly, also using two rolls is the A and B roll method. The main difference is that instead of changing from roll A to roll B at every cut the change only needs to be made where there is a dissolve. For example, if your film is neg cut in A and B rolls but not checkerboarded, the original will be matched to the cutting copy by using numbers in the way already described. Only when the original is joined does the difference between A and B roll assembly and checkerboard become apparent. In the checkerboard system alternate shots are placed on alternate rolls—if scene one is on roll A scene two will be on roil B scene three on roll A and so on. When A and B roll assemblies are used, scene one may be on roll A and scene two, if it cuts on to scene one and does not dissolve into it, can also be joined onto roll A and so on until a dissolve is reached. The incoming shot of the dissolve can then be placed on roll B. The following shot can be joined again on roll B and continue until the next dissolve when the incoming scene can be placed on roll A. You only need to change from one roll to the other where two scenes must overlap. For practical purposes the checkerboard system, though taking slightly longer to prepare, is undoubtedly the best system to use. If you have to use it, you should use a frame line cement joiner making the smallest possible cement join (1/16th of an inch) overlapping each join towards the black leader which parallels the following shot on the other roll. You will thus ensure that the join is invisible.
Optical cue sheets
For fades in or out you do not, of course, need an overlap though you will need to tell the laboratory where they are to occur. When you are winding through to check the cut rolls of camera original, you zero the footage counter on the synchroniser at the point where the leader is joined to the first frame of the action. When you come to the start of the first optical, you make a note of the footage from the head of the roll. You should repeat this process as each optical starts so that when you reach the end of the roll you will have a complete list of the footages at which each optical effect occurs. This optical cue sheet should be sent with the cut camera original to the processing laboratory, when you order a print.
In an A & B assembly you only move from roll to roll when you need an overlap. Scene 2 cuts on to scene 1 and scene 3 on scene 2—all level cuts, so the original is cut and joined on the same roll (A) Scene 3 dissolves to scene 4 so an overlap is needed and provided by putting the incoming scene on a separate roll (B). 4 cuts on to 5 to 6, all on the same roll until the next dissolve—6 to 7—when we go back to roll A. Dissolves and wipes require an overlap. Fades do not, so you can keep shots requiring fades on the same roll.