Mike, When you and Jay suggest that short duration flashes might be less perceptible (than equal energy longer flashes, I guess), my initial, strong impresion is to regard that as nonsense. It's totally at odds with my experience. But you and Jay are careful, faithful observers, so that creates some dissonance. But, do you suppose that some eyes are more sensitive than others to short flashes? I have long found strobe lights annoying. In fact, now that I think about it, the very idea of "decorating" a recreation area with strobe lights, such has been done for disco, etc. is crazy. Completely crazy. I've never been to such a place and if I found myself there, I'd want out. Immediately. Strobe lights are too intense, too invasive. Are these circumstances related? Has there ever been any research on individual variation in perception of short flashes? Any ideas for search terms for AltaVista, etc.? Maybe I should ask Ron Coursen if he has a reaction to strobe lights. One thing I do know about him is that he has a remarkable(?) ability to recover a satellite on the next rev without having a "prediction"; at least an ability far beyond mine. If we are going to need a group of experienced observers to serve as test subjects for hypotheses (related to short flashes), might it be desirable not to mention this phenomenon (if that is what it is) beyond SeeSat-L, at least for the time being, leaving available, and preserving as a resource, those without access to SeeSat-L? Cheers. Walter Nissen dk058@cleveland.freenet.edu --- Earnestness and productive affect are the hallmarks of suitability for a SeeSat-L message.