Out of curiosity, what shutter speed and f-stop would you recommend? Wouldn't it change depending on what you were photographing? For instance a beam shot into the air or a subject like a house?
larry, im actually new to taking night time beamshots, but have done night time photography for several years
the few beam shots i have done, what i try to do is set the exposure to where you can just faintly see the subject, or close to what the naked eyes sees
then lock it down in manual, lock the white balance, shutter speed, and f-stop
they all play a vital role in how the pics will turn out
so if i have my camera set at say 8 seconds, locked down on a cell tower for instance...take the pic....review the pic and have to really strain to see the tower in the preview blown all the way up, i call it good.
then when i take the pic of the light shining on the tower, i know " ANY EXTRA LIGHT THAT IS SHOWN ON THE TOWER" has to be coming from the flashlight itsself, because all of the settings in the camera have remained unchanged....
if you go the other way too far, and have a pitch black pic, underexposed for too many f stops, then you will be doing your lights a horrible injustice, and they wont put the light on the subject as good as in real life ....
hope all this made some sense ;)