progress toward making color prints more econanical is being made and 

 in the future they should not be disregarded automatically for this 

 reason alone. 



When black and white prints are desired, black and white negative 

 materials are used. There are many sizes and types of black and white 

 negative film available commercially. However, in general it has been 

 found that black and white film smaller than 35 mm. prove unsatisfactory 

 for black and white prints and it is usually desirable to use larger 

 black and white film (size 2-l/4"by 2-l/4"or larger) because much less 

 difficulty is encountered in obtaining acceptable enlargements. Of the 

 commercial film available, the most widely accepted is the panchromatic 

 type; that is, film which is sensitive to light of all frequencies of 

 the visible spectrum. In the recent past, orthochromatic film (film 

 which is sensitive to all light of visible spectrum except the reds) 

 was the most popular film especially in box cameras, since this type of 

 film had much wider exposure latitude than the panchromatic film 

 available. However, recent developments in the photographic industry 

 have produced panchromatic film with a wide exposure latitude and these 

 have largely replaced the orthochrcmiatic film used previously, perhaps 

 almost to the exclusion of orthochromatic film for general purpose 

 photography. Most of the panchromatic or orthochromatic films commer- 

 cially available serve very well for use in beach photography. 



All films are assigned an emulsion speed number which is simply 

 a number indicating the relative amounts of light required to properly 

 expose the film. These exposure index numbers are used in conjunction 

 with a light meter to properly expose the film for the lighting of any 

 scene being photographed. The most prominent system of film rating 

 used in this country is a system of relative numbers developed by the 

 American Standards Association. Under this numbering system, any film 

 having an exposure index of 6 or less is considered a slow film; any 

 film having an exposure number between 12 and 50 is considered a 

 medium speed film, and any film having an exposure number from 100 to 

 800 is considered a fast film. Films with exposure indexes in the 

 medium to fast range, or having as ratings from 50 to 100, are generally 

 best suited for beach photography. 



In the less critical sense, the film exposure, which simply means 

 the amount of light allowed to reach the film, determines whether or 

 not a picture will be obtained. When a film is either extremely over 

 or under exposed, no picture will be obtained. In a more critical 

 sense, a film exposure determines the quality of the final picture in 



*Graphic Graf lex Photography , 8th edition, W. D. Morgan and H. M. Lester, 

 New York 17, New York, 1950, p. 25. 



