A few normal things can make Live View look sharper than the final file.

First, Live View may not be showing exactly the same depth of field or shutter behavior as the actual exposure. If the shooting aperture or shutter speed differs at capture, the recorded image can look softer from shallower DOF or blur.

Second, if you shoot RAW, the camera preview is usually a processed JPEG-style preview with sharpening applied. The actual RAW file will often look softer until you add sharpening and contrast in post-processing.

Third, images can appear sharper on a small camera/LCD preview than when you inspect the captured file more closely.

What to do:

• Judge sharpness from the actual captured image, not just Live View.
• Confirm your final exposure settings, especially aperture and shutter speed.
• If shooting RAW, apply appropriate sharpening in your editing workflow.
• Review the image at consistent magnification when comparing preview vs capture.

For macro jewellery work, even tiny differences in depth of field are very noticeable, so checking the recorded file is the most reliable test.