Stereoview card of Telegraph Hill as seen from Nob Hill. I saw this image in the book "Earthquake Days" and found an original card on Ebay. These are original photographic prints mounted on cardboard. Stereoview photographs are taken by a camera with two lenses, which takes two separate photos about 2.5" apart, which is approximately the distance between our eyes. The photos appear identical , but in fact are both slightly different. When viewed with a stereoviewer, the two views assimilate into one, and the brain percieves the image in 3D. Stereographs (and magic lantern slide shows) were very popular at the turn of the century. 3 1/2" x 7" , H.C.White Co. 1906.
Magic lantern slide showing the destruction of City Hall. 3 1/4" x 4" Underwood & Underwood Co. 1906. Another Ebay find. Basically, a photographic lantern slide is a positive print of a photograph on a glass slide. Lantern slides were “matted” by a piece of opaque paper laid on the slide, which both masked out edges or parts of the image not wanted in the frame. Finally, a second slide of glass was laid atop the glass slide with the positive print and these two pieces of glass were bound firmly together by pasting a strip of paper around the edges. The sandwiched glass plates held the matte or mask in place and also protected the positive photographic print from dust and scratches.The final slide was then ready to be viewed in a lantern slide projector.
© Joseph Greco