SPECIAL APPLICATIONS OF INFRARED PHOTOGRAPHY
Many applications of infrared photography are of such importance that whole chapters in this book have been devoted to a treatment of them. In this chapter consideration is given to some of the uses which have not been discussed fully elsewhere. It should be read in conjunction with those chapters which concern the general practice of infrared photography (Chapter II), photographic darkroom practice (Chapter III), the characteristics of materials (Chapter IV), and the sources of infrared radiation (Chapter VII).
A subject which is of outstanding interest is the photographic penetration of haze. Its understanding is basic to the use of the infrared in landscape photography, survey work, reconnaissance, and so on. Chapters XIV and XV have, therefore, been devoted to its detailed consideration. In order that the photographer shall not be confused by a mass of detail, however, the practical aspects of haze penetration are dealt with here. The fuller study, important for the best understanding of the practice and its limitations, has been relegated to a later section of the book.
A very popular application of infrared photography is photographing landscapes. The special effects which it produces can be obtained with the ease of ordinary photographs and have an appeal as a consequence of their striking contrasts and their clear rendering of the detail of distant objects. The chief characteristics of infrared landscape photographs are as follows:
Haze is penetrated so that hills and distant detail, which might otherwise be flattened, are rendered sharply. This natu-