I was wondering when you do use the PVS-14 with the front cover with the small peep hole? It seems very grainy with the peep hole cover since ou have to turn up the gains. Thanks.
Use it briefly with the cover on during daylight. As had been said to test function or sight in. Few minutes won't hurt anything but long term will burn a center dot in your tube.
I have such a tube. Cap off for dark and on for daylight conditions. Keep its use for daylight to just a few minutes at a time to be safe.