Sel16f28 focus ring hard to turn

Rubber focus ring can be purchased in ebay.
The rubber ring may be attached to the lens with glue. Use denature alchohol between the rubber and lens to remove the rubber ring. It can be stretched little. Once removed, clean any glue on the lens and stretch the new rubber ring and install.

Almost all lenses get dust inside them. It's rarely bad enough to affect image quality in the slightest so is usually ignored.

The only fix is to pay to have a Sony service centre strip down the lens, clean it, and reassemble it, but it would be far cheaper to sell yours and buy a new example. Either way, unless you never take the lens out of the packaging it will soon get dust inside it again.

Take it to a reputable camera repair shop for a CLA (Clean-Lube-Adjust). It's more or less the equivalent of a tune-up and oil change for a car.

turn the 'lock/friction ring' (metal band just below the black rubber focusing ring) counter clockwise whilst holding the focusing 'ring' still. The friction/lock ring is used to prevent 'lens creep' when carrying the camera with lens pointing down, or using the lens when it is pointing down. Juust turn it until it applies the level of friction you prefer for operating the lens. If you have already tried this and it won't budge it may be the bearings are shot and you will need to contact a canon service centre for repair.

1) try cleaning the lens with a damp cloth, 2) check if it has an adjustable focus ring on the front of the lens you can turn to improve focus, and 3) follow the tips in the article How To Improve Your Webcam Video Quality.

Hello there! Focus ring lock means that some how the focus ring is not turning freely. If it turns easilly then inside the optocoupler unit which reads out the movement of ring must be dust or damage.in the flexicable. Therefore somehow the camera should be disassembled got cleaned by pressurized air in case of dust and reassembled and hopefully it should work without problem.

Make sure the lens is clean first. And then you can focus the camera by turning the ring around the lens as you view the camera focusing on something. As you turn the ring it should come into focus and and remain clear.

I believe the ring around the eye moves and will focus.

Did you make sure the lens was clean? Wipe lens off the reset the webcam to its default settings. Slowly adjust the focus ring for best effect then adjust the video settings.

This will need technical service eventually. Try temporary solution with Sellotape or similar