The volumes of the LIFE Library of Photography deal both with the technological nuts and bolts of the subject -- how cameras and lenses work, how light interacts with film -- and with the nature of the art, showing how great photographers have interpreted great themes. In this book the editors have ventured out to the frontiers-- both technical and esthetic -- for a look at where photography seems to be heading. One clear trend is the resurgence of interest in abstraction. While most picture taking is, and probably will continue to be, "straight," a great many photographers are working with non-objective subject matter (or even no subject matter at all) and using every darkroom technique they can think of to produce pictures different from what most people are used to seeing. Whether this is good or bad, an advance for the medium or a corruption of it, is up to the viewer to see for himself. On the technical frontiers, a lot is going on, some of it fascinating mainly to laboratory scientists from whose domain it may never emerge, and some of it very likely to affect the photography the rest of us do. The future is crowded with new ways to automate picture taking, new imaging systems, new applications of holography, that all-but-occult subscience that already has come up with the spookiest apparitions since the last appearance of Caesar's ghost. There appears to be no limit to what can be invented -- but there is a limit to how much new equipment can go from lab to factory to corner camera store. The limit is economic: if the cost of the dream camera is too high or the demand too low, it will stay in the future until its time comes. But except for the limitations of their own pocketbooks, photographers needn't worry; the new, the different, the better is on the way. On all frontiers, growth continues.