According to Wiki:
Bulb, is a shutter speed setting on cameras that allows for long exposure times under the direct control of the photographer. With this setting, the shutter stays open as long as the shutter release button remains depressed. The term bulb is a reference to old-style pneumatically actuated shutters; squeezing an air bulb would open the shutter and releasing the bulb would close it.
Nowadays the bulb is an electric switch and can be completely wireless too. My big gun, my Canon 5D has a bulb setting and I have recently purchased a corded remote trigger for it. The above photo is an initial experiment. The streak of white light is from a car’s headlights. Notice though that the street lights are overexposed. For bulb photography to work best, you need a dark environment.
Living in metropolitan Saint Louis, I live at the bottom of a light well that might as well be a black hole for all the stars that I can see from my house. But opportunity is knocking later this summer. While I’m on vacation in the UP of Michigan, I’ll be close by some truly dark skies. The above map show the Lake Superior shoreline in the vicinity of Sault Ste. Marie, MI. Anne’s beach front cabin is just within the orange ring surrounding the Soo.
Studying this map, I was surprised to see how deeply that the cabin had slipped within the light well surrounding the Soo. I can remember my midnight sojourns of yesterdays to the outhouse. If you didn’t turn on the porch light or bring a flashlight, then you were going to walk into a tree. More recently, even after the advent of modern conveniences, one sometimes avails themselves of the biffy. Flashlights are no longer required, even with the vegetation no longer being trampled upon so regularly.
I am contemplating an astronomical expedition. I’ll drive west on Lake Superior Shoreline Road also-know-as the Curly Lewis Highway. Maybe camp the night at Bay View Campground, but that only gets me to the blue ring. There is a nice site at the turnoff for Naomikong Point. It is up on a dune, but even there is still in the blue ring. A few miles further west is a lakefront turnout, just within the black, with few trees around. I think that that is the place to go.
My house is in a yellow zone and close to a green zone. Tucson has strict dark sky laws to help protect Kitt Peak National Observatory
I think most of the light comes from the airport in SSM Canada. and the town itself. it was so much darker ‘back in the day’.