Date: 1855 - 1880 |
These are objectives of several different designs. They all have non standard threads, predating the adoption of the RMS standard, still in use. The first three from the left are manufactured by Hartnack; they are model numbers 7, 4, and 7. The fourth from the left is early Leitz model number 2 in the style of Belthle. The third from the right is Merz of Munich 1/12". The second from the right is unknown and first on the right is Leitz model number 4. (Thanks to Dr. Timo Mappes for identifying these objectives.) more...