Screw-mount Leicas have many charming idiosyncrasies and focusing can be a hassle, especially in dim light. Leica’s solution: a tiny round filter that mounts over one of the rangefinder windows on the front of the camera. This gives the rangefinder image a contrasting orange tint that makes it easier to align the moving and stationary images, even though it darkens the rangefinder image somewhat. It was listed in the catalog under the code name ORAKO for Leicas II to IIIa, and as the OKARO for Leicas IIIc to IIIf, a production run approaching 40 years.
If you want to acquire one, make sure you get the right one for your Leica. The older ORAKO measures 10mm and the later OKARO measures 11mm—both measurements refer to the inside diameter of the mounting ring that slides over the front bezel of the rangefinder windows. Both will fit over either rangefinder window, and Leica fans still argue over which works best. How much will an ORAKO or OKARO set you back? Currently, they’re running from about $75-$150 on eBay. #TBT#LeicaSociety