The standard adaptor allows any M42 lens to be used with full range focus to infinity. This adaptor features an inner shoulder which depresses the aperture pin on the lens thereby allowing auto diaphragm only lenses to be used manually. This is not suitable for Pentax ES lenses.

The KOOD adaptor option will work with ES lenses, but they need to have A/M switches so that the aperture can be set manually. Auto only lenses are not suitable.