At the moment the center of gravity of the device is located in the frontal part, that causes that the viewfinder continually depletes down, moving the point of clarity of the lens and causing that it is blurred, constantly you have to readjust the viewfinder due to the weight frontal. My suggestion is to improve the ergonomics of the viewfinder in its next generation and the center of gravity to compensate the frontal weight, a good option would be to add the battery in the back of the device.