When you are looking your negatives over to discover their good and bad points you must remember there is only one thing that really matters - how will they print?

This is obvious enough, but it is often quite difficult to make the man who does not do his own printing see that it does'nt matter how beautiful the negative may look if it does not produce a good print.

In judging the quality of your negatives you must be careful not to confuse density with contrast. Broadly speaking, density is the thickness of the silver image and is governed by the exposure given to the film.

Contrast is not the thickness of the image but the difference in thickness between the highlight and shadow portions of the image and is governed by the development of the negative.

Density is not an important factor in negative quality provided it lies within the wide latitude of a material such as

Eastman Portrait Film. If the correct exposure for a certain subject is two seconds and exposures of two, four and six seconds are made and the three films developed in the same developer for the same length of time, they will vary in density but they will all have the same contrast and yield equally good prints, the only difference being in the time required to make the prints.

On the other hand, if two identically exposed films are developed, one for six minutes and one for twelve minutes, the resulting negatives will vary greatly in contrast. And you can not have much difference in contrast without seeing a very great variation in the prints.

A negative which is lacking in contrast will yield a flat print with little difference between the highlights and the halftones or the halftones and the shadows.

The Important Difference Between Density And Contr StudioLightMagazine1923 292


By Charles L, Peck Buffalo, N. Y.

A negative with excessive contrast, if printed for detail in shadows, will have blank high-lights, while if it is printed for detail in the highlights it will have blank black shadows. And if printed for the halftones, both shadows and highlights are likely to be lost.

The perfect negative is one that will give a print in which there is some detail in even the highest lights and this detail in highlights is secured before the shadow detail is lost in blackness. Naturally such a result is not secured on a paper of great contrast but rather on one of the papers having the long gradation scale necessary for portraits, such as Vitava or Ar-tura.

Naturally when making high keyed portraits, such as those of children, in which there are no strong shadows, there will be a much smaller range of contrast in the negative. This result should be secured by a soft broad lighting and not by the method of developing the negative.

You will find in practice that much more latitude is allowable in exposure than in development. In fact, a variation of eight or ten times in the exposure may not ruin a negative because its contrast might not be greatly changed. But such a great difference in time of development would certainly destroy the quality of any negative made under normal conditions. The latitude in development is small so it is very important to keep the time and temperature normal.

If you will look through your old negatives you will probably find that some of the failures you attributed to faulty exposure were, in reality, due to faulty development.

An Error

In the September issue of Studio Light in the article reviewing the Washington convention of the P. A. of A. we made the statement that the cup awarded to the Chicago exhibit of commercial photography was the Abel cup.

We find however, that the prize cup was purchased by the Com-merical Section from a fund given to this Section by the National Association and we are pleased to make this correction. It was the Commercial Section's Cup.

The snappy catch lights seen in delicately lighted white draperies are recorded by Eastman Portrait Film and reproduced in the print.

An Error StudioLightMagazine1923 294


By Charles L. Peck Buffalo, N. Y.