RobinWa wrote in post #11648135
What is the hinge point like? Screw?
Is it easy to open a little bit to rotate the lens without risk of it opening fully (and dropping the entire set-up)?
The following applies to item #169-309, Meritline's Tripod Mount Ring A2 for Canon Tele Lens & Zoom, Fit Canon EF 70 200 F4L (IS) Canon EF 80 200mm F2.8L Canon EF 400mm F5.6L Canon EF 200MM F2.8L 169-309 for $19.99
The hinge point appears sturdy to me and consists of a hollow steel pin (not molded but a piece of steel rolled into a cylinder) with the ends flared to hold it in place. There's some play in the hinge but this allows the ring to make full contact with the lens body when tightend down.
The locking mechanism consists of a spring-tensioned screw-down knob which extends into a beveled slot in the end of the ring. Turning the knob extends a pointed screw into the slot locking the ring closed and tightening the ring. You have to pull the knob with a moderate amount of force against the spring's tension to release the ring lock and open it. Once the knob is screwed down past a certain point, however, the knob can no longer be pulled and the ring lock can't be opened at all. You can back off on the knob to loosen its grip on the lens for rotation with no chance of the ring opening accidentally. When completely locked in place, however, the lens can still be rotated with a moderate amount of rotational force applied so you could potentially rotate the camera and lens accidentally.
Overall construction appears quite robust with (cast?) aluminum with steel hardware. There is no plastic at all. The paint job is close to matching the L's but still slightly off if you look hard.