The proper place to correct the imperfect negative is in the darkroom and at least 90% of the negatives that will permit of after treatment can be corrected by reduction, assuming, of course, that very few darkroom workers under-develop.

All negatives should at least have the normal time of development. There is no excuse for under-development when tanks are in such general use and it is so simple to develop for a given time. And it is better to over than under-develop for the negative is more readily corrected.

Reduction will correct two different negative faults provided the correct reducer is used. The first is over-exposure which produces too much density if the negative has normal development. The over-exposed negative should not have less than normal development because short development will reduce its contrast.

The second fault is excessive contrast caused by over-lighting, under exposure or over development, which produces negatives that are harsh and unpleasing. Contrast can be reduced with the proper reducer provided the negative has been fully developed.

When you watch the development of an over-exposure you will notice that the entire surface of the negative flashes up as though exposure had been equal over all parts. But as development continues and you hold the negative to the light you find there is an image beneath this surface silver deposit, and you must give the full time of development in order to reach it and bring it out.

Though your negative may have been quite a bit over-exposed you can still secure a very good result provided you develop full time. Then to remove the excessive density, which is almost an even deposit of silver over the entire area, you must use a reducer which will cut away this silver equally over all parts. The well known Farmer's Reducer or the Permanganate Reducer given below have this action.

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By D. D. Spellman Detroit, Mich.

Farmer's Reducer


Water 1 oz.

Potassium Ferricyanide 15 grs.

Water 32 ozs.

Hypo 1 oz.

Add A to B, use a white tray to see results best and work by artificial light. When sufficient reduction is secured wash the negatives thoroughly.

Permanganate Reducer


Water 1 oz.

Potassium Permanganate 24 grs.


Water 1 oz.

Sulphuric Acid, C. P. 1/4 dram

The negative must be thoroughly washed to remove all traces of hypo before it is reduced.

For use take 1 dram A, 2 drams B and 8 ounces of water. When the negative has been sufficiently reduced, place it in a fresh Acid Fixing Bath for a few minutes, to remove yellow stain, after which, wash thoroughly.

The negative which is too contrasty from over-lighting or which has been under-exposed and forced in development but which has no more density in the shadows or lower tones than is wanted, can not be reduced successfully with Farmer's or Permanganate Reducers. Such reducers would completely cut out the shadow detail before they had sufficiently reduced the highlights and the excessive contrast of the negative would actually be increased.

There is. however, a selective reducer which attacks the heaviest body of silver in the highlights without materially affecting the shadows or halftones unless an excessive amount of reduction is attempted. This reducer will lower the contrast of a negative and should be used when such results are desired. It is the Persulphate Reducer given below: Be sure the negative has been thoroughly fixed and washed before it is placed in the reducer.

Persulphate Reducer Stock Solution

Water 32 ozs.

Ammonium Persulphate (E.K.Co.) 2 oz. Sulphuric Acid, C. P. 3/4 dram

This solution must be made at least twenty-four hours before use. Take one part of stock solution to two parts of water. When sufficient reduction is secured place the negative in a fresh fixing bath for five minutes and wash thoroughly.

We have suggested a general reducer and a selective reducer

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By D. D. Spellman Detroit, Mich.

and there is still another type of selective reducer discovered only a few years ago and known as the Proportional Reducer. Its action is very remarkable for it actually reduces in proportion to the amount of silver deposit of the negative. By this we mean that in the same length of time that it removes one-half of a heavy silver deposit in the highlights, it will remove no more than one-half of a lighter silver deposit in the halftones or a still lighter deposit in the shadows. So you see its action is quite remarkable as it proportionately reduces density without at all reducing contrast. It is most useful when you merely wish to make a good negative print quicker without in any way affecting its contrast or quality.

Proportional Reducer Stock Solution


Water 32 ozs.

Potassium Permanganate 4 ozs.

Sulphuric Acid (10% Solution) 1/2 oz.


Water 64 ozs.

Ammonium Persulphate 2 ozs.

For use take one part of A to three parts of B. When sufficient reduction is secured the negative should be cleared in 1% solution of sodium bisulphite. Wash the negative thoroughly before drying.

You may use only the first of these reducers because it is most simple, but there are many occasions when the second could be used to decided advantage. Reducing contrasts in the dark room will often facilitate retouching and printing and enable you to secure a better result in the finished print.

Make or buy a Negative Comparator and use it in your darkroom. It should have three openings, each covered with opal glass, one for a white and one for a black background negative and the one in the center for a piece of plain opal glass, in front of which the developed negative is held for comparison. Each compartment should contain a small frosted lamp for illumination. When you have carefully chosen your standard negatives for the correctness of their printing quality, place them in the Comparator and judge all of the negatives you develop by these standards.

If you will do this you will probably find you can do a lot of correcting and that it will save a lot of time and raise the standard of your work.

Thousands of film users, experienced work-ers, all of whom had used glass plates., deliberately gave them up for the superior quality of the Portrait Film negative.

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By D. D. Spellman Detroit, Mich.

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