Run the check
Clean the lens and hold a printed subject at a fixed distance.
Compare the browser preview under brighter and dimmer light.
Check the same camera in one other local app before judging a call recording.
Read the result
Improvement with light suggests noise reduction or exposure, not necessarily focus damage.
Limits and next step
Preview sharpness cannot prove the remote call's encoded resolution.
Repeat the check after changing one setting or connection. Keep a record of what changed before deciding whether the device needs service.