A rare lens hood made by Cook & Perkins Ltd., a British company also known for manufacturing lens barrels for Dallmeyer and others.
It fits perfectly on the Elmar 50mm f3.5 with A36 mount. The hood is attached to the Elmar with a locking screw, and by rotating the front part of the hood, the aperture can be adjusted—a clever and practical design. Aperture values are engraved around the outer rim, marked f3.5, 4.5, 6.3, 9, 12.5, and 18, in continental style.
This hood greatly inspired the design of our own original Elmar hood, FB-07. It remains a mystery why Leitz, known for producing such excellent accessories, never made a hood like this.
Made of aluminum, it is lightweight yet finely crafted. The anodized surface has developed a wonderfully subdued patina over time, exuding the kind of character reminiscent of a well-used Angénieux 50mm f1.8 Type S1 or 35mm f3.5 X1.
A truly irresistible piece for accessory enthusiasts.

It shows considerable signs of use overall, but no noticeable dents or impacts are present.
Next to the area where the Elmar’s aperture lever makes contact, the letter S is engraved.
The ring operates smoothly, and it has been confirmed to fit the Elmar properly.
With its bold and refined appearance, it complements not only Barnack Leicas but also black paint Leica M models beautifully.