Yes, this is basically me talking to myself.
Amulet of Shadow Sight
By clenching this amulet with one's eyes closed and concentrating for one turn, the user gets a cloudy vision into the Shadow of Ptolus. This means no real objects are visible, but their shadows clearly are, whatever the ambient light level. This results in a -2 Spot modifier and a 20% miss chance against any target up to 60', which replaces any vision-related penalty. Further targets, or things that don't cast a shadow within the demi-plane, are invisible to the amulet. Opening your eyes ends the effect, which can be activated six times per day, to a maximum of one hour each.
Note that from the user's perspective, this should be described as seeing everything's shadow, and nothing else. There are no obvious cues that one is looking into a demi-plane - until they run into Kadmiel or equivalent, which should come as quite a surprise. The effect has been made rather horrible under normal circumstances so that nobody would go around with the effect on.
Divination CL whatever, I don't use d20.