Fast flare.
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The 50mm f/1.5 Leitz Summarit.
1972/3 saw me as a member of Leica Postal Portfolios which was a photo interchange/critique club where you circulated a large box of 12″ x 15″ prints by mail, adding yours and critiquing those of other members. It seems that it exists to this day. There were some 12 members in my group, a friendly bunch of Leica fanatics. You learned a lot and made some great friends. We all did our own processing and printing.
One of those friends loaned me his Leica 50mm f/1.5 Summarit lens which was as fast as they got back then. Two stops faster than my pedestrian f/2.8 Elmar, it was based on a 1930s Zeiss Xenon design (Leitz paid Zeiss royalties) and, while coated, still flared pretty mightily at full aperture. And full aperture it was when I headed out on the street to the nearest telephone booth:
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Call girl. The Summarit at f/1.5. TriX.
I actually rather like the way the flare works here, enhancing the feeling of night. I just “rescanned” this with the D800 and it’s come up better than ever.