Female T2 M42 Step Up Coupling Adapter Review

Many years ago some people made accessories for telescopes. Their factory was designed to produce tools with a thread pitch of 0.75mm. Instead of converting the standard 42mm x 1.0mm thread used for cameras, they made it with an odd 0.75mm pitch. So almost 100 years later we are suffering from two incompatible M42 streams. one is used on telescopes (42mm x 0.75mm) and the other on cameras (42mm x 1.0mm). When camera equipment needs to be connected to telescope equipment, an adapter ring is…