Q: Why does my camera say "Lens not attached" or unrecognized ?

A: This is a manual lens, no electric contacts, your camera will not detect the lens when mounted, that's why showed this notice, pls setting camera mode to M mode to make lens work.

Why does my picture out of focus and very blurry ?

Pls lock the"Lock-Open" ring, then rotate the focus ring on the front body of the lens until the subject is in focus , and focus with live-view to achieve accurate focus. Recommend use with a tripod and remote to keep image stable

Why picture are too dark/ too white ?

if picture is black , pls slower shutter speed. such as 1/500 seconds to 1/400 seconds until image normal. if image is white, pls raise the shutter speed more faster, such as 1/500 seconds to 1/800 to 1/1000 seconds until image normal.