The flanged reel containing the film and the apron may be inserted in the tank either end first, and should be gradually lowered into the solution by means of the hook.

The developer quickly reaches all parts of the film, but the reel should be lifted a little five or six times with the hook to expel air bubbles. Take care, however, not to raise any part of the reel above the surface of the solution. The developer recommended is that supplied under the name " Developer Powders for Kodak Film Tank." When obtaining the developing powders the purchaser should be sure to specify the size of the particular tank in use, as the powders are made in different sizes for the several developing tanks. In cold weather the solution should be prepared by dissolving the contents of the large packet in two or three ounces of luke-warm-not hot-water in the tank, filling up the tank with cold water to the embossed or projecting ring which will be found near the top of the tank, and then adding and dissolving the contents of the smaller packet. The object of this is to ensure that the developer is not too cold, but there is no need to use any luke-warm water in summer as the temperature will be already sufficiently high. Very cold developer should not be used. The solution should be freshly mixed, and should be used once only. Care should be taken to see that the powders are thoroughly dissolved.

If any of the powder in the smaller packet sticks to the paper, dip the paper in the solution so as to dissolve all the powder.

The best technical quality in the negative is obtained when the temperature of the developer is from 60° to 65° F. (16° to 18° C.) Ascertain the temperature by means of the Eastman thermometer.

Time and temperature are the two chief factors in developing with the " Kodak film tank. With a given temperature of developer the best results will be obtained by developing for a certain length of time. A warm developer acts rapidly, and a cold developer slowly. It can be readily understood, therefore, that very careful attention to these points is necessary if you would have the best results. If the temperature of the solution is beyond your control the effect of variations from the foregoing figures may be very largely corrected by increasing or reducing the time of development, according to the following table :-

Temperature.

Time

One pair of powders.

Time

Two pairs of powders.

70° Fahr..... 21° Cent.

69° „

68° „ .... 20° „ 67° „

66° „ .... 19° „

65° „ Normal 18° „

64° „

63° „ .... 17° „ 62° „

61° „ .... 16° „ 60° „

59° „ .... 15° „ 58° „

57° „ .... 14° „ 56° „

55° „ .... 13° „ 54° „

53° „ .... 12° „ 52° „

51° „ .... 11° „ 50° „

49° „ .... 10° „ 48° „

47° „ .... 9° „ 46° „ .... 8° „ 45° „ .... 7° „

15 Minutes 16

17 ;„

18 ;„

19 ;„

20 ;,, Normal

21

22 ;„

23 ;„

24 ;„

25 ;„

26 ;„

27 ;„ 28

29 ;„

30 ;„

31 ;„

32 ;„

33 ;„

34 ;.,

35 ;„

36 ;„ 37

38 „ 39

40 „

8 Minutes 9

10 „ Normal

11

12 „ 13 14 15

16 17

The temperature of the developer must not exceed 70° Fahr. (21° Cent.), as above that point there is a danger of the emulsion softening or melting. 45° Fahr. (7° Cent.) is the lowest temperature at which the developing powders can be dissolved, and even at this temperature the powder must be finely crushed and added slowly to the water.

It is best to work at the normal temperature (65° Fahr. or 18° Cent.) when possible ; the use of a developer that is colder than normal has a slight tendency to increase the contrast in a negative, while the use Of a developer warmer than normal makes the resulting negatives slightly less contrasty.

Place the lid on the tank, secure it firmly, and allow development to proceed for twenty minutes when using one pair of powders, for ten minutes when using two pairs of powders in the same quantity of water.

After two minutes' developing, turn the tank bodily upside down, and repeat this operation several times during development.

Negatives developed according to these directions, particularly if the exposures have been properly made, will give good prints. Different individuals, however, have different ideas of the proper density in a negative. Some admire strong, plucky negatives, others prefer a thinner variety. If the results by the figures given do not coincide with your ideas, you can, by modifying the temperature or the length of development, secure pictures which will more nearly approach the ideal you have set yourself. Careful notes of the temperature and duration of development should be taken, however, so that negatives of a standard character may be secured at any time by repeating the conditions which best suit the individual worker.

Note

Some photographers like to wet the surface of their films before applying the developer, in order to ensure an even flow of the solution and avoid the possible formation of streaks. This can readily be done with the " Kodak " film tank. Instead of putting the flanged reel immediately into the developer, fill the tank with clear, cold water. Immerse the reel bearing the film in this for a few seconds-pour off the water and proceed as described on page 252.