Autofocus (AF)is not available. Stop-down metering is used. Spot metering does not work properly. Although it is possible to use A (aperture priority AE) mode in auto exposure, the aperture display is not available. The aperture display in M (Manual) is not available. In P (Program AE) or S (Shutter speed - priority AE) mode, the shutter releases, but the auto exposure control does not work. The distance scale on the OM system lens may not indicate the actual distance. Always use the viewfinder for focusing