Neutral gray card
Your color exposures will be more accurate if you use a
Four situations where a gray card helps.
TO A GREAT EXTENT, the success of your color shots depends upon accurate exposure, which influences not only the overall darkness or lightness of the transparencies, but their color quality as well.
Many people have an idea that there is no problem to exact exposure for color shots — that they can depend entirely upon an exposure meter to prevent mistakes. This is not always the case, however. The exposure meter is a necessary and reliable tool for color shots, but when using a reflected-light type meter, there are many instances where its use in the usual manner will not result in a well-exposed transparency.
For example, readings from this type of meter are likely to be inaccurate in such instances as the following: (1)
when the subject is rather small and there is a difference in brightness of background and that of subject; (2) when the subject cannot be approached for a meter reading; (3) when the subject just isn’t there for a meter reading before you actually take the picture (as in sports events) ; (,|) when the level of illumination is so low that it hardly moves the needle of the meter.
For these and similar situations, there is a remedy—the neutral gray test card made by Eastman Kodak Company. These cards are available at most photographic supply shops; they are about 8x10 inches in size, gray on one side and white on the other.
Here's how this neutral gray test card can help to get accurate meter readings in the specific instances mentioned. (1) When small objects are photographed, the proper exposure is not indicated by the meter— (Continued on page 102) because it is affected to a greater degree by the background area than by the subject. A dark background will cause too low a reading, resulting in an over-exposed subject on the transparency—a light background tends to produce underexposure of the subject. For such shots, hold the card in front of the subject, with gray side facing the camera, point your expôsure meter at the card from a distance of not more than four or five inches, then take a meter reading. Care should be used to keep from casting a shadow on the card—either with your hand or with the meter.
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(2) There are times when you cannot approach the subject to take a meter reading. An example of this situation is shown in the photograph numbered 2, accompanying this article. The shot was made from the roof of a tall building; the exposure meter could not be turned toward the subject of the picture for a reading, because the great expanse of sky would have caused a reading that was too high. The result would have been a loss of shadow details (underexposure) in the transparency. Taking the reading from the gray card, however, produced a wellexposed color shot. Here, the card should be held in camera position, in the same type of illumination as that received by the subject—that is, if the subject is in sunlight, the card would be held in sunlight; if the subject is in shade, the card is held in shade. And always with the gray side facing the camera.
(3) There are times when the subject isn’t around for a reading to be made. This occurs in such situations as sports events, many action shots, at rodeos, or in similar instances where you have selected a spot from which to take your pictures. You know when the action you want to photograph will take place, but the subject hasn’t appeared in the spot you’ve selected, and you know that when it does appear you may have just time to make one quick exposure before subject passes out of range. Obviously, in such a situation it would be impossible to take a meter reading at time of action, but you can take a preliminary reading of the exposure meter from the gray card, while awaiting the appearance of the subject. Make sure that the card is held in the same illumination as that to be received by the subject, turn card toward camera and make your reading.
An example of this technique is illustrated in photograph No. 3, which shows a water skier who was flashing by at about 35 miles an hour. Exposure meter reading had been made from the gray card, in advance, the camera was set accordingly, and a satisfactory action shot was achieved.
(4) When the level of illumination is so low that the needle of the exposure meter hardly moves, it is difficult to calculate the exposure accurately. Here again, the neutral test card will be of help, but in this situation it should be held in front of the subject with white side turned toward the camera. The white side reflects exactly five times the quantity of light refleeted by the gray side, which of course gives the exposure meter five times as much light to register. When the exposure is calculated from that reading, it should be multiplied by five for the actual exposure, to assure greater accuracy at low levels of illumination.
When photographing brightly colored (light) subjects, exposure meter reading taken from the gray card as it is can be used. For average subjects, the camera should be set according to the reading, and lens then opened up a half stop for the actual exposure. For moderately dark
When Subject Is Meter-Indicated Exposure Taken off Gray Card Is to Be Increased by Light No increase. Normal V2 stop. Rather dark 1 stop. Dark IV2 stops. Very dark 2 stops. Indicated meter exposure taken from the white side of the card (in dim light) is to be increased 5 times, then adjusted according to the table above.
subjects it should be opened one full stop, and for really dark subjects, IV2 stops. This information is supplied here merely as a tentative guide to begin with. A little practice with the neutral test card will enable you to judge results and adjust your lens opening most accurately according to brightness of subjects. The accompanying table will prove helpful in this connection.
There are other advantages to be gained from the use of this neutral test card. The instruction sheet supplied with the card lists them in detail.
One of the most satisfactory aspects of its use as described is the reliability of the results. It is difficult to standardize your procedure if you take your refiectedlight exposure meter readings directly from the subjects of your pictures. There are so many variable elements that you cannot have any assurance of getting good results constantly. But the neutral test card is always the same, and its use enables you to repeat standard results consistently.—