I found some information in a Swedish Catalogue from 1934 which surprised me. The Busch Nicola Perscheid was offered as a significantly cheaper alternative to Cooke's Series E and D (f3.5) and the Universal Heliar. First of all, the coverage given was rather different from what has been implied in previous threads here.
30cm covered 9x12 to 12x16.5
36cm covered 12x16.5 to 13x18
42cm covered 13x18 to 18x24 (all these are give in cms)
This is somewhat in conflict with the coverage given in various ebay listings and a single listing here (FS).
But the most interesting thing was the text at the bottom:
"These objectives are supplied together with the yellow filter which is necessary for the correct use of these objectives".
What yellow filter? I have never heard these mentioned in any listing. Is it a device for correct focussing or, as I suspect, like the Plasticca, whiere it is an integral part of the optics?
Bookmarks