A barn door tracker follows the movement of stars so I can do super long exposures of the sky. The scope on the far right is used to point a the polaris star. Then, while the shutter is open, you slowly turn the black handle which will move the platform in sync with the sky. I calculated it so it was one rotation per minute, which allows me to follow a second hand to ensure I'm moving it at the correct speed.
Full view of the astrophotography rig.
Plans for the barn door tracker. It isn't exactly how it came out, but the plans were invalueable! (Plans are worthless, planning is priceless)
The stars move at 0.25* per minute, which is why you get lines where the stars are if you take a 10+ second photo of the sky. A barn door tracker allows me to mount the camera on a hinge, point it at the polaris star, and slowly move the camera up 0.25* per minute by turning the handle.
