Investigating further, the Spyder 3 appears to use the TAOS TSL238T sensors (See <http://www.taosinc.com/productdetail.aspx?product=45>) Given that the sensor is pretty similar to that in the Spyder 2 (Something like a TSL237S-LF - see <http://www.taosinc.com/productdetail.aspx?product=41>), and the other optics are fairly similar to the Spyder 2 LCD setup (an overall high pass/shape filter, an opal diffuser, a Fresnel lens, then the individual sensor cutoff filters), it's hard to understand why it behaves so differently at low light levels. Graeme Gill.