To Develop Take

No. 1.

No. 2.

Water.

For Instantaneous Exposures.........

.1 oz.

1 oz.

4 oz.

For Portraits .......................................

.1 oz

1 oz.

5 oz.

For Landscapes,

Sen. 20-27.. " 16-20

1 oz. . 1 oz.

1/2 oz. 3/4 oz.

3 oz. 4 oz.

For Full Exposures,

For Lantern Slides,

..............

.1 oz.

3/4 oz.

4 oz.

For Full Exposures,

and 2 to 6 drops 10 per cent solution of Bromide of Potassium to each oz. Developer.

Note. - More of No 1 will increase density, more of No. 2 will increase detail and softness. Temperature of Developer should not vary much below 65° or above 75°. The after-treatment is the same as with any other Developer.

Eastman's Developer For Transparency Plates

No. 1.

Oxalate of Potash.............1 lb.

Hot Water.....................3 pints.

Acidify with sulphuric or citric acid.

Test with Litimus paper.

No. 2.

Photo-Sulphate of Iron......1 lb.

Hot Water..................11/2 pints.

Sulphuric Acid........1/2 dram.

Or Citric Acid..............1/4 oz.

No. 3.

Bromide Potassium..............1 oz.

Water......................... 1 quart.

To Develop Take

No. 1, 6 oz.; No. 2, 1 oz.; No. 3, 1 dram. Mix in the order given. Use cold.

Hydrochinon Developer

No. 1.

Hydrochinon..................154 grs.

Sodium Sulphite.............. 2 ozs.

Sulphurous Acid............... 1/4 oz.

Distilled Water to............. 10 ozs.

No. 2.

Carbonate of Sodium Crystals............................1300 grs.

Caustic Potash............... 154 grs.

Distilled Water............. 10 ozs.

To use, mix together 1 oz. of each and add 3 ozs. of water.

Eikonogen Developer

No. 1.

Dissolve 2 ozs. of Sodium Sulphite in 10 ozs. Distilled Water and add 1 drachm of Hydrochloric acid. To this add

Eikonogen.....................125 grs.

Water to make................ 25 ozs.

No. 2.

Carbonate of Sodium.........2 1/2 ozs.

Caustic Potash................125 grs.

Water to make................25 ozs.

To use, mix in equal parts and add restrainer as in Pyro Developer. We do not recommend this developer to the amateur, for if not carefully handled there is a liability to fog.

Glycine Developer

No. 1.

Glycine........................300 grs.

Sodium Sulphite..............2 1/2 ozs.

Distilled Water............... 10 ozs.

No. 2.

Potassium Carbonate............1 oz

Distilled Water..................4 oz.

To use, mix 1/2 oz. of No. 1 and 1/4 oz. of No. 2, and add 3 oz. of water. Use restrainer as in Pyro Developer.

The above is a favorite formula for developing films. After the film is fixed and washed it should be soaked for five minutes in water 25 ozs., and glycerine 1 oz. This latter bath has a tendency to keep the film soft and pliable. In developing films they should be treated exactly the same as plates except that they should be soaked in water for about ten minutes, and when developing they should be turned over often, first film up, then film down. The developing should be continued as a rule until the image is denser than that on an ordinary plate, as films seem to lose their density in the hypo more than the average plates do. After washing and giving them the glycerine bath they should be pinned to a board to dry, in order that they may dry perfectly flat.

Rodinal Developer

Rodinal is a ready prepared developer which is manufactured in Berlin, Germany, and is prepared from para-midophenoL It is a light brown liquid, which is sold in two-ounce bottles. In the case of a normal exposure the developer should consist of 1 part of Rodinal to 25 parts of water. In case of an over-exposure use 1 part of Rodinal to 15 or 20 parts of water, and a 10 per cent solution of bromide can be used with it the same as with other developers. In the case of an under-exposure, use 1 part of Rodinal to 30 or 40 parts of water. A half dozen 4 x 5 negatives can be developed with 1/2 drachm of Rodinal to 1 1/2 ozs. of water.

Tolidol Developer

This developer is the first and in fact, the only developer invented and manufactured in America.

In addition to this distinction, which is purely a patriotic one, is the incontestible fact that it is superior to any and all of the old developers in the number of its perfections and the uniform quality and regularity of its action.

Tolidol is an ideal developing agent for plates and films, as well as for developing papers. Its action is rapid, yet gradual and easily controlled. It does not stain the hands or plates; is not injurious. It dissolves easily, even in cold water. When it is made up accord-ing to the formula it will keep in solution before and after use, ordinary care being taken. It can be used repeatedly. Tolidol gives beautifully clear negatives, preserving all the fine gradations and delicate details in the high lights as well as in deep shadows. It is excellent for white drapery or flesh detail and fine effects in Rembrandt lighting. It allows the production of a great variety of tones.

It is excellent for lantern slides and transparencies, for process work, copying work, reproductions and for bromide paper.

Tolidol meets every requirement and is very economical. One ounce makes two and one-half to five gallons of developer, according to taste. One-half grain to one ounce of water will act on a sensitive time-exposed plate. It requires small portions of sulphite and carbonate.

To add more would be equivalent to asserting that we know more than the plate makers and any of them would tell you that that is not and cannot be so.

The use of the alkali in all developers, is to open up the pores of the gelatine to permit the developer to get at the silver salts. When you have accomplished this, any further addition of alkali will simply produce fog and photographers using solutions in which the alkalies are separate, as in two solution developers, should be careful not to add an excess of alkali, as it is bound to prove detrimental to the plates. Many of the published formula err in this respect and many a good formula is rendered greatly inferior in the hands of a careless operator through using too much alkali. Beware of developing formula that contain potash, as potash gives a much stronger and harsher action than soda and is rapidly being discarded in favor of soda for that reason. A further point is that by confining the chemical operations to the use of the various sodas much is gained in simplicity and the liability to serious reactions in developing and fixing solutions and in toning and fixing solutions will be avoided, especially where solutions are kept and used over and over again until exhausted or spoiled.

Bromide of ammonia is highly recommended as a substitute for bromide of potassium as a restrainer, having a less clogging effect in the highlights. It is used as a 10 per cent solution. Chloride of sodium, common table salt, is also excellent as a restrainer in a 10 per cent solution. In using the latter be careful not to restrain too much, as 4 to 6 drops of chloride of sodium will have as much restraining effect as to oz. of a like solution of bromide of potassium, but a badly over-exposed plate restrained with chloride of sodium will be much clearer than the same plate treated with bromide of potassium.

Keep the temperature of your developing solution as even as possible and avoid extremes. If necessary in summer, put a piece of ice in your developing tray to keep the solution down to 700 and in winter warm it if necessary to bring it to that point.