I am talking about the crappy picture you get out of those smoke dector cams whether its a GE or a Speco. They wash out with too much gain as they look down, any sheet of paper reflects the ambiant ceiling lite to the point of whiteing out the picture.
I wonder if you would get a Good picture taking a good box cam like a bosch or a pano 484 and putting a pinhole lense on it [lense are $$$]
So i quess the dollar amount between lense and camera would be $500.00 + , but would it make for a good picture? [ oh yea, forgot to mention the 1to 2 hours you take setting up and installing this cam into a ceiling tile thru a pin hole?

Have you tried any cameras from www.KJBSecurity.com ? I've had good luck with their covert products.