I can't improve on my oldest photographically usable lens, but here is a new one from, at latest, 1825. Of some optical history interest, too!
Fraunhofer had a short and dramatic career within optics, both practical (glass production and telescope/optics making) and theoretic (spectroscopi - Fraunhofer dark lines and defraction).
The manufacturing quality is way beyond anything I have seen before (UK makers!)!
The achromat has a focal length of 45cm, diameter is 3.5cm, giving an F of 12.8.


Reply With Quote

Bookmarks