I think the max IR range is about 30 feet for animate objects and about 50 feet for vehicles. If it's behind a glass window, camera housing, range reduced. I think the zone area size also influences the sensitivity. This is about what I see on my 410s. I think any thermal background can affect sensitivity. I also suspect the resolution settings influence this... with fluid being less, but don't remember for sure. Are you using the Client or a DVR?