The author of this article, in company with Mr. G. E. Trager, has praeliced " Home Portraiture " with a Kodak for eleven years, with the most notable success. The wide difference in the light conditions in the various houses where the pietures have been made, rendered it necessary to have some accurate means of measuring the intensity of light, and after considerable experimenting, Eastman's Solio Paper used in conneelion with simple tables, was adopted as the exposure meter, with such success that the proper timing of negatives ceased to be one of the questions in praelice.
During the last four years in which the Solio has been employed for measuring light, not a single failure has been made in exposure, unless per haps through forgetfulness in placing the right diaphragm. Eastman's Transparent Film has been used entirely in this work, and during the winter of i9o2-3, which was spent in Merida, Yucatan, fully two thousand exposures were made and the negatives developed in the Kodak Developing Machine without the loss of a single one.
The term "Solio Time" used in this book expresses the a5tinic inten sity of an illumination, and it should be used just as other simple terms are used to express other quantities or conditions, as : " The Solio Time at this head is eight seconds." " The Solio Time of this landscape is one half second." Just as one would say : " The length of this stick is four feet ;" or, " The temperature of this room is seventy degrees." The adoption and use of this term for the expression of aCtinic values or intensities will do much to solve the problem of photographic exposure.
The " Solio Time " at any subjea being once known (by measurement with the Solio Paper) the exposure becomes simply some modification of that time according to the color and contrast chara&er of that subje61, and the seleEtion of a certain diaphragm.
To obtain the greatest universal good from the use of this unit expres sion for actinic intensity, the photographic workers should use some method of counting exael seconds, such as the one given in this article.
The most delightful phase of photography is portraiture. If in the past it has been considered most difficult by the amateur, it has been because of a lack of clear and concise instructions how to proceed.
Generally, the greatest difficulty in portraiture is the lighting of the subjeEt and the timing of the exposure. The objea of this book is to pre sent a most simple, and at the same time accurate method of determining the right exposure to give ; and to offer suggestions as to lighting which will enable the amateur to make good portrait piEtures.
In home portraiture a window having a full view of the sky should be seleCted if possible. It should preferably be on the shady side of the house so that the sunlight will not enter it. If the window is low, pin a dark cloth across it covering as high up as the subjea's head, so that light will not come up from below on to the face and strike the lower part of the features and spoil the modulation. See that no brightly lighted part of the room, as a window or door, is in range of the lens.
Place the subjeel about the width of the window away from one of the casings. Turn the face exaelly toward the window and then have the sub jeCt turn the head gradually away until one side of the nose is seen to become shaded and the shadow of the nose rests somewhere on the cheek. The light must strike a little upon both eyes and both cheeks. The eyes should look in the same general direCion that the face is pointed. This is the lighting with which at least ninety per cent. of all portraits, which are intended as likenesses, are made, whether in painting or photography.
It is the light that best models all the features of the face, and there fore best reproduces the likeness of the subject. Now place the Kodak so as to take in the view of the face that is desired. Reference to the accompanying diagrams will help you. Adjust the Kodak at the proper height. The lens should, for a bust portrait, be about on a level with the nose.