Cars

46 Number 43, Fall 2002 cartographic perspectives is not a map. Paintings such as these are unable to provide, anywhere and in any respect, the topographic, conceptual and metric information which one expects from a map" (Imhof, 1982). Although Imhof's words are unequivocally discouraging, it is impor- tant to remember the context in which they were written. Recognizing that few other people possessed the artistic ability and geographic expertise to paint maps such as Walensee, that the technology of the day was inad- equate for the mass reproduction of painted maps, and that cartographic employers were not demanding such products, his admonitions were, it seems, intended to keep impressionable students from wasting their time. The Walensee map is a tempting but forbidden fruit. One can only speculate about what Imhof might have said differently had he lived long enough to experience the widespread adaptation of DEMs, Photoshop, the Internet, and other digital tools. Aerial photograph maps While Shelton and Imhof were exploring map realism via art, others were pursuing a more technical approach using aerial photographs (and, later, satellite images). A snapshot of the Earth from above, aerial photographs are the ultimate in geo-realism providing cartographers with a means to deliver pure and uncensored geographic information to the reader (Keller, 2000). And aerial photograph maps are easy to make. Just place some type and lines on rectified aerial photography, such as a USGS Digital Ortho- photo Quadrangle (DOQ), and the map is finished, and you can go to lunch. Despite these advantages, outside of the engineering, surveying, and scien-tific fields, aerial photograph maps have not caught on for gen- eral cartogra-phic use. Aerial photographs contain inherent flaws, particu- larly in moun-tainous areas, that translate poorly to the graphical format of maps. Flaws include: Relief inversion - Most aerial photographs and satellite images are taken in mid morning when the atmosphere is clear and when sun- light originates from the lower right or southeast (in the northern • "Aerial photographs contain inherent flaws, particularly in moun-tainous areas, that translate poorly to the graphical format of maps." "One can only speculate about what Imhof might have said differently had he lived long enough to experience the widespread adaptation of DEMs, Photoshop, the Internet, and other digital tools." Figure 2. Traditional approaches to cartographic realism: (left) A much reduced portion of Eduard Imhof's map of Walensee, Switzerland, painted in 1938. The original measures 200 x 480 cm. Source: Virtual Library Eduard Imhof, Map Collection, Swiss Federal Institute of Technology (ETH). www.maps.ethz.ch/imhof_engl.html (right) Aitutaki, Cook Islands. A colorized aerial photograph depicts the coral reef. Source: New Zea- land Department of Survey and Land Information. Crown copyright reserved. www.linz.govt.nz/services/topo-hydro/pages/topo/topographicmaps/topo-downloads.html

• Cover