Advices

Infinity focus position:

The position of the infinity mark [∞] of the telephoto lens or super telephoto lens is shifted slightly to the positive side to enable focus adjustment even when focus shift is caused due to temperature changes. The shift range is denoted by an L-shaped line, Be sure to check the focus through the viewfinder even when you shoot at infinity.

'No Lens Attached' - Warning Message Appears:

The camera needs to be set to function without an E-Mount lens attached. You can do this by changing the following camera setting: 'Menu' -> 'Setup' -> 'Release w/o Lens' -> 'Enable' (Exact naming and location of this option may change depending on camera model). If your lens does not have a manual aperture control ring, it will stop down to its smallest f/stop by default.

Set camera "release shutter without lens" to enable when using the adapter for the first time, or the camera will fail to recognize the lens and the shutter may not be released.