This is likely due to either a calibration problem with the camera’s viewfinder or an incorrect installation. KatzEye™ Optics has never had a calibration issue that traced back to the manufacture of our screens - we individually check, measure, and record the data from each one; so we simply do not ship them if they are not correct. However, we have run into several cases of cameras that were not calibrated correctly at the factory. Since the autofocus and viewfinder calibrations are completely separate, it is entirely possible (and not that uncommon) to find a camera where the AF is accurate and the MF is slightly wrong. This happens with all camera manufacturers to one degree or another - when a manufacturer makes a million units of a product, a few are bound to be out of specification.
When problems of this nature are encountered, it is important to first confirm that the installation of the screen was completed correctly. In most cameras, there are one or more rectangular spacers (called ’shims’) which fit above the focusing screen and serve to establish the correct calibration of the viewfinder. Sometimes one can stick to the old screen or fall out when you remove it, but it is important that all of the shims stay in the camera and that the shim(s) are properly placed above the focusing screen (inserted before the screen) to maintain the factory calibration. If one of the shims were missing or placed incorrectly, that will cause a calibration problem. It is also important that the screen is seated flat in the recess and that the retainer is properly latched.
If the installation has been confirmed to be correct and the problem remains, then it is likely that you have a camera with a miscalibrated viewfinder. Please contact us for technical assistance. In many cases we may be able to help you install a different shim or perform other operations to correct the problem in the field, or we can help you make arrangements to send the camera to us for calibration by our trained technicians.