> so I can stay up late >drinking beer and smoking cigars. >
My kind of photography trip
Anyhow thanks Jose, I always struggle to find a good target and enough light for the test photo and hadn't thought about the benefits of very long exposure combined with moving the camera around! (otherwise it can be a struggle to differentiate marks on the wall from sensor grime)
Pete, thanks for the confidence inspiring example. My local dealer cost is $70 so it looks worthwhile to build this expertise oneself.