In a properly made plain lighting there should be strong, snappy high lights, and the shadows should be soft and silky, but not flat and lifeless. When I have a class in this lighting I point out to them the direction taken by the light when falling on a subject correctly lighted. The proper direction for the light to take is through the center of the face, from the high light down over the nose to the chin.
If too much top light is being used, it will give a spotted light-ing. That is, the shadows in the eyes, under the nose and chin will be too deep and lacking in definition. On the other hand too strong a light from the side will give too much contrast. The light side of the face will be too harshly lighted, while the shadow side will not have enough light to give the roundness, so much admired in portrait work.
If we work our light so that it falls too much from the front, we have equally as great a trouble as either of the others mentioned, and that is - flatness. This is caused by the light falling on the face in too much of the same "key" from the top of the head down to the chin, and thus taking out all of the character, and expression of the fact. This should not be. The light should be the most intense on the forehead and should then run down to a "key" much lower by the time it has reached the chin. In no case should the light side of the face be blocked up from the high light on the forehead down to the mouth. Even the temple should be a perceptable shade less in strength than the high light on the forehead.
Neither should the cheek back next to the ear on the light side of the face be quite as strongly lighted as it should on the rise of the cheek bone. This trouble of lighting the back of the cheek too strongly is caused by turning the head away from the side light too for, thus shifting all of the lights on the face too far to the rear of the head.
On the other hand, we should not have one broad streak of light on the shadow side of the face, extending from the eye down to the chin, as we would have were we to turn the head facing the side light more than necessary.
Our method for making this lighting so as to reconcile these two points, viz.: The proper position of the high light on the light side of the face, and the amount of light on the shadow side of the face has been to turn the head away from the side light, until the shadow cast by the nose, and the shadow from the cheek almost blend together. We have said almost blend together, for it is this one point on which the position of the light, on the light side of the face hinges. If we were to have our subject's head turned far enough away from the light to bring these two shadows together it would at once be seen, that our high light on the light cheek had shifted too far to the rear. Now if the curtains have been arranged properly the shadow from the nose will fall away at an angle of 45 degrees, and it should be borne in mind that the farther down the top curtains are drawn the farther across the cheek this shadow will extend, by reason of the fact that the side light will strike directly on the side of the nose, and of course the shadow will be thrown behind the point where the light strikes. Therefore, if we notice the shadow falling too straight away from the nose, we may know that the side light is in excess of the top light.
On the other hand if we find that the shadow from the nose falls almost directly under that very important feature of our face, we know that the top light is in excess of the side light. The remedy is obvious. To give a more definite idea of how this shadow should fall, we would say that if the lighting is corectly made, that a straight edge if layed directly in the shadow and allowed to follow it up, and over the nose, one end of the straight edge will rest in the deepest shadow on the face, while the other end will rest on the highest light - the forehead. The deepest shadow on the face should be near the corner of the mouth on the shadow side of the face.
There is one more point, which, if noticed carefully, will assist one in making this lighting and that is the little catch lights in the eyes. These small specks of light add more life and expression to the eye than any other one thing I know of; without them, in this lighting, the eyes become expressionless, and have no snap.
If the head has not been turned too far away from the light, the catch lights will be distinctly seen in both eyes, and it is a safe plan to turn the face away from the light just as far as possible, without losing the catch light in the shadow eye, for the reason that as soon as the halftone on the shadow side of the face disappears, the catch light in the shadow eye will also be lost. In fact this little touch of light, or halftone on the shadow cheek, and the catch light go together, and when one is lost, the other is lost. Hence, we say, it is safe to turn the head away from the light as far as possible, without allowing the catch light to leave the eye. If the face is turned far enough toward the light to bring the high light in the center of the forehead instead of over the eve, the catch light will be directly in the center of the eye, blocking up the pupil, and thus giving a staring expression to the eye. The proper position for the catch light, should be in the upper edge of the iris of the eye, at a 45-degree angle above the pupil.
Sometimes we hear operators complain that the catch lights are "scattered," that is, they have more than one catch light in each eye. This is caused by having your skylight divided. The catch light is an exact reproduction of the skylight in miniature. This you can easily see for yourself by examining closely. Every section of glass can be easily seen reflected in the eye. Therefore, if your catch lights are "scattered," it is because more than one source of light is being used, or in other words, the curtains on the light have been so arranged that the light does not fall together. This remedy is to join all sources, or cut off some of the parts that are objectionable. One of the most serious causes of this trouble is where the side and top lights are divided by a heavy beam or wide division, as is the case in numbers of galleries we have seen. It is almost impossible to get the catch light in good shape where the operator has this fault in the skylight to contend with.
It may be that some have plain glass lights instead of the ground glass, and do not care to go to the expense of putting in the ground glass, and yet would like to secure the effects of the latter light. If so, we would suggest that waxed paper can be purchased of any stockhouse, and if ironed on the light with a warm flatiron will give a very pleasing light.