<P> The oldest surviving photograph of the image formed in a camera was created by Niépce in 1826 or 1827 . It was made on a polished sheet of pewter and the light - sensitive substance was a thin coating of bitumen , a naturally occurring petroleum tar , which was dissolved in lavender oil , applied to the surface of the pewter and allowed to dry before use . After a very long exposure in the camera ( traditionally said to be eight hours , but now believed to be several days ) , the bitumen was sufficiently hardened in proportion to its exposure to light that the unhardened part could be removed with a solvent , leaving a positive image with the light areas represented by hardened bitumen and the dark areas by bare pewter . To see the image plainly , the plate had to be lit and viewed in such a way that the bare metal appeared dark and the bitumen relatively light . </P>
<P> The oldest surviving photograph of the image formed in a camera was created by Niépce in 1826 or 1827 . It was made on a polished sheet of pewter and the light - sensitive substance was a thin coating of bitumen , a naturally occurring petroleum tar , which was dissolved in lavender oil , applied to the surface of the pewter and allowed to dry before use . After a very long exposure in the camera ( traditionally said to be eight hours , but now believed to be several days ) , the bitumen was sufficiently hardened in proportion to its exposure to light that the unhardened part could be removed with a solvent , leaving a positive image with the light areas represented by hardened bitumen and the dark areas by bare pewter . To see the image plainly , the plate had to be lit and viewed in such a way that the bare metal appeared dark and the bitumen relatively light . </P>
how long did it take to take a photo in the 1800s
how long did it take to take a photo in the 1800s
After a very long exposure in the camera ( traditionally said to be eight hours , but now believed to be several days )
After a very long exposure in the camera ( traditionally said to be eight hours , but now believed to be several days )