Hello, I have a Switar 50 mm f 1.4, regular c-mount which I had used a bit many years ago.The glass appears to be quite good. The aperture ring functions well and the focusing ring also seems to be in at least decent shape, based on eye-balling a ground glass and guesstimating distances.
However, the Visifocus function isn't working. When the aperture is set at f 22, only one of the copper dots appears, at the widest depth of field indicator. As soon as the aperture is opened up more the dot disappears, not to be seen again. The second dot never appears.
I have attached a photo of the one dot visible at f 22.
Does anyone know what the problem might be and if this can be remedied by me with some relatively simple fix? I am selling some equipment to raise funds for a project and would prefer to sell a fully functional lens. Thanks.