Halation has been observed from the earliest days of photography, but it became more common on the introduction of glass plates.

In commercial work, halation is seen in its most aggravated form in a negative of an interior which includes a bright window - in portraiture, around a white collar or dress where the white comes in sharp contrast to a deep shadow.

The thicker the glass on which the emulsion is coated the greater will be the halation. The strong rays of light pass through the emulsion to the back of the glass and are reflected back to the under side of the emulsion, causing the fog or halation.

Naturally, the thicker the glass the greater will be the spreading of the light, and the greater the angle of these strong rays of light, the greater will be the breadth of the halation, so it will be readily seen that a window at the extreme edge of the plate will show greater halation than if it is placed directly in the center. The straight rays of light passing throug the center of the lens reflect, but not at so great an angle.

One may get the idea that if halation is not seen in a distinct blurred line between a highlight

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EASTMAN PORTRAIT FILM NEGATIVE, ARTURA PRINT

Eastman Professional School Demonstration

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EASTMAN PORTRAIT FILM NEGATIVE, ARTURA PRINT

Eastman Professional School Demonstration

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EASTMAN PORTRAIT FILM NEGATIVE, ARTURA PRINT

Eastman Professional School Demonstration and a deep shadow, it does not exist, but such is not necessarily the case.

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In portraiture one may light white draperies in such a way that they are filled with snappy little catch lights, but if the light is strong and a glass plate is used, there may be enough halation, or spreading of the light which has gone through the emulsion, to reflect back and destroy the separation in the highlights. The effect which was seen in the lighting may be entirely destroyed and the highlights be blocky and without gradation.

Plates are backed to prevent halation, but backing is usually mussy at best. The double coated plate has done more to remedy halation. The slow emulsion of the under coating does much to stop the bright rays which have penetrated the faster surface emulsion. If extreme over-exposure of highlights is not necessary to produce detail in the shadows, the double coated plate will usually solve the halation problem. Double coated plates are necessarily more expensive than single coated plates, but when the nature of the work is such that they will produce the most satisfactory results - they are worth the difference.

However, there is now a remedy for halation - a product which, to a very great degree, overcomes the trouble by removing the condition which causes

halation. We speak of the new Eastman Portrait Film.

Eastman Portrait Film, while primarily intended for portrait work, is even now used commercially by many who have seen the great advantage of the thin film as a means of overcoming halation, as well as for its many other physical advantages over glass plates. And as halation became common with the use of glass plates, so will it become more and more uncommon with the increasing use of films.

We know of no way to overcome the lateral spreading of light in the emulsion itself, but Portrait Film will do more towards preventing halation than any plate can do.

The gradation quality of the film is equal if not superior to that of the best plates, the grain is exceptionally fine, while the speed is fully equal to that of the Seed 30 Plate.Aside from these qualities, Eastman Portrait Films are absolutely unbreakable, extremely light in weight and occupy the minimum amount of space in storing.The lack of halation in Portrait Film makes it possible to retain all the snappy points of light in the highlights of white drapery and preserves the modeling throughout the negative, giving a quality not possible to secure with a portrait plate.

Many of these effects of halation have been looked upon as unavoidable, but with Eastman Portrait Film the lack of halation is establishing a new standard of negative quality.

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EASTMAN PORTRAIT FILM NEGATIVE, ARTURA PRINT

Eastman Professional School Demonstration

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PRACTICAL SUGGESTIONS IDEAS THAT HAVE BEEN TRIED BY PHOTOGRAPHERS AND FOUND TO BE USEFUL

In placing labels on bottles where it is desired to varnish over same to make them waterproof the lettering often looks mussy. To overcome this trouble use waterproof drawing ink for writing the labels. They may then be gone over with any of the varnishes and the ink will not run.

To make a retoucher's pencil sharpener cut a one-half inch board about three inches wide and ten inches long trimming one end down to make a convenient handle.

In one edge of the part which is left full three inches wide cut a deep groove and make a long narrow wedge to fit loosely in this groove. Cut a piece of fine emery paper to the proper length and about eight inches wide. Wrap it tightly around the wood so that both loose edges may be turned down into the groove.

Drive the wedge in the groove and it will hold the paper as tight as though it had been tacked or glued, yet may be removed and new paper substituted with very little trouble.

An improvised filter holder may be quickly made from a plate box which has a double cover. Place the two covers, one in the other, and cut an opening through both covers slightly smaller than the filter to be used. Place the filter between these covers with strips of cardboard of the same thickness at the sides to hold the filter in front of the opening. Cut a round opening in the bottom of the plate box the exact size of the lens barrel and directly opposite the filter. Put the box together and slip on the lens. The filter will be held tight and if the round opening is the right size the box will fit snugly over the lens barrel.