Quote: On the D80, is there a safety shift type of thing which will override the settings if that's going to result in over/under exposure? This might be a reason why you tell it to open the shutter for thirty seconds and it does something else.
Could be right....the headlights in the pic are probably a bit too bright already. It maybe that the scene is simply too bright to allow for a 30 second exposure.
I looked in the manual on Nikon's website - the camera can be set so that it shifts the ISO sensitivity if needed, but this is off by default and I couldn't see anywhere that it could override the selected exposure settings, so this is probably a maroon mackerel.
-------------------- John
Who could suppose that angels move the stars, or be so superstitious as to suppose that because one cannot see one's soul at the end of a microscope, it does not exist?