Fabric, Golden Fading
different factors of plate, stop, time, and subject; the exposure being read off and modified, according to the time of year, from a table on the back compiled by Dr. Scott, by whom the instru-ment was devised.
Counting the Time of Exposure. Possessors of a watch with a second hand will have no difficulty in counting the duration of a lengthy exposure, but for shorter periods than this some other aid is required. Most modern watches tick five times in a second - occasionally one may be picked up which ticks four to the second; there are also cheap stop-watches on the market, which have an extra hand marking fifths of a second, and which can be stopped or started in one-fifth of a second. It has also been suggested to use a bunch of keys or a bullet tied to a stringins. in length, which, when set swinging, beats half-seconds. But in many cases it is desirable to look at the subject whilst making an exposure, especially when such is of short duration; it then becomes impossible to look at a watch or swinging body at the same time. Therefore, it is convenient to practise the counting of seconds. Accuracy can only-be ob-tained by practice, but it soon becomes easy. A convenient method of counting is as follows: Say, for instance, 3 sees, are required. As soon as the cap is removed, count I, 2, 3, 4; 2, 2, 3, 4; 3, 2, 3,4. Again, we will supposesec. is required, 1, 2, 3, 4; 2, 2. It will be seen from this that four are counted to the second, and each second begins with the number which the four when counted will complete.
Fabric, Golden. A translucent cloth, coloured yellow, used for the dark-room window. It should always be tested to see whether actinic light filters through, as described under Dark-Room (q.v.).
Fading. The worst of all ills to which good or interesting negatives and prints are subject; but in some cases a benefit to humanity.
Negative fading. This is due to insufficient washing or fixing, and the consequent action of hypo on the delicate image of silver.
Fading of Prints. The cause of this may in most cases be traced in some way or other to sulphur, or its compounds. Albumen itself contains a minute trace of sulphur, and conse-