I have an Olympus XA which has unclear focussing. In a newer model I have, the split image is very clear and quite obvious, the older model is not. Does anyone know if cleaning it would help. I am reluctant to take it apart until I am sure cleaning will work (otherwise it is perfect).
Cleaning the viewfinder lenses will help and may be enough. However, if the half-silvered mirror is cloudy or has lost some of its coating all you can do is replace the mirror. Cleaning it will often make it worse.