A supplement to Ures Dictionary of Arts, Manufactures, and Mines, : containing a clear exposition of their principles and practice. . otographic paper very smoothly. Having covered this withthe cushion, which may be either of flannel or velvet, fix the back, and adjust it by the bar,until every part of the object and paper is in the closest possible contact; then turn upthe frame and expose to sunshine. It should be here stated, once for all, that such pictures, howsoever obtained, are callednegative photographs; and those which have their lights and shadows correct as in nature—dark upon a li
A supplement to Ures Dictionary of Arts, Manufactures, and Mines, : containing a clear exposition of their principles and practice. . otographic paper very smoothly. Having covered this withthe cushion, which may be either of flannel or velvet, fix the back, and adjust it by the bar,until every part of the object and paper is in the closest possible contact; then turn upthe frame and expose to sunshine. It should be here stated, once for all, that such pictures, howsoever obtained, are callednegative photographs; and those which have their lights and shadows correct as in nature—dark upon a light ground—are positive photographs. The mode of effecting the produc-tion of a positive is: having, by fixing, given permanence to the negative picture, it isplaced, face down, on another piece of sensitive paper, when all the parts which are whiteon the first, admitting light freely, cause a dark impression to be made on the second, andthe resulting image is correct in its lights and shadows, and also as it regards right andleft. For obtaining pictures of external nature, the camera obscura of Baptista Porta is 6G1 562
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License: Licensed
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Keywords: ., bookcentury1800, bookdecade1860, bookpublishernewyo, bookyear1864
