Basics For Cueing And Light Changes
Before we discuss more Sight Grading, B&W and Colour Grading we need to know about cueing.
Whatever method we use for grading we will have two pieces of information we have to pass to the printing machine. "HOW MUCH LIGHT AND WHEN"
The "HOW MUCH LIGHT" is the result and purpose of our grading.
The "WHEN" is the point in the film when we want to give that particular amount of light.
The "when" can be determined and communicated in many ways. It is usually known as cueing. Cueing is the method we use to transfer the results of grading to the printing machine. The very first method was by the printing operator feeling for a join and making an exposure change at about the right time. This was not terribly satisfactory nor convenient because if there were a scene change without a join then he would not know where to make the change. The next step was to cut a notch at the join so that the operator could more easily feel the light change. It also meant that if you did not want a change at every join or wanted a change in between joins you could have one.
Once the notch became established it was not long before different printing machine manufacturers began inventing systems to automate the light change mechanism.
Bell and Howell on their D and J printers moved the notch to six frames after the scene change and used the notch to operate a micro switch (often called an interrupter). That micro switch operated an electromagnet that was connected to the shutter operating mechanism via a calibrated lever (numbered from 1 to 22). The mechanics were arranged so that the operator could pre-set the light value and when the micro switch was triggered, that value was transferred to the shutter. The operator then pre-selected the next light value.
The grading information was written on a card with each value in a box. The machine had a pointer that moved down the card every time the micro switch was operated. Because the operator only had the time between light changes to set the next value, it was normal practice to indicate fast changes. The fast change was sometimes a box around the light or a line down the side of the lights. Debrie on their Matipo printers and others used the notch cut at the scene change. The Debrie notch was longer than the B&H notch. Because the micro switch was above the gate, a rotary clutch was used to delay the light change until the correct frame was in the gate.
The notch was the standard method for cueing films. If you examine an original feature negative, you will often find that the negative will have B&H notches on the one side and Debrie notches on the other side.
This is because the answer and show print would have been printed on a continuous printer such as the B&H Model D for speed. When the Fine Grain Duplicating Positive was made after approval of the show print it would be made on a Debrie step printer for maximum picture quality and steadiness and to avoid perforation pitch problems you get on a rotary printer when making two stage dupes. Normally the negative is short pitch and the positive is long pitch because they are lying on top of each other on the rotary printer’s main sprocket. When you are making a Fine Grain Positive and then a duplicate negative on a rotary printer they would both need to be first long and then short pitch for the two stages. The solution is to use a step printer.
