Taking astrophotos or time lapse often involves leaving a camera out in the dark for long periods. Cameras are somewhat more robust than humans, tolerating the cold for a bit longer. As a result often the cameras are unattended while the human seeks shelter in some warmer place. This can result in the theft of the unattended camera.
This was recently highlighted when a camera was stolen from near the Keck 2 telescope last week. Left outside for a nighttime time lapse it simply vanished. We all commiserated with the victim in a Facebook conversation, we have all run the same risk and worried about this happening to us. I usually place the camera somewhere inaccessible to the public or somewhere remote enough that it is unlikely to be found. I still worry.
On the mountain is not the only place this risk exists. I have often left a camera operating for hours in my driveway at the front of my house attached to a telescope. In an attempt to make it somewhat more difficult to simply grab and run I designed a simple security device. A little block of aluminum with a slot that accommodates a standard computer cable lock.
Machined from aluminum the block took very little time to make and provides a great deal peace of mind. It is not impervious to a determined attack, but does prevent the camera from simply walking away. In place of aluminum it could probably be 3D printed if you do not have a machine shop available. With a little more patience it could be manufactured with simply hand tools.
The slot is the standard Kensington security slot, a 3mm x 7mm slot as found in almost all laptop computers. The locks are available from just about anyplace that sells computer accessories.
The screw I use is a tamperproof button head screw, one that requires a special tool to remove. A standard hex button head screw would probably work in most situations, it is unlikely that an opportunistic thief will have a set of allen keys handy.
The block can be used on a telescope, with the cable wrapped around a tripod leg. It can also be used on a tripod, a ¼-20 hole is tapped to allow the block to sit between the camera and the tripod head. The security cable can then be secured to anything available. Atop Mauna Kea there are many railings, guardrails and signposts that would provide a solid locking point. In nature there are fewer steel poles, but a tree trunk or something similar would also serve.
The design can be modified to suit ones needs, the mechanical drawing above shows the device in its simplest form. As you can see in the photo my prototype block includes two screw holes for the camera and a 3/8″ threaded hole for larger tripods. I also put a second lock slot on the bottom to have the option of having the lock stick out in a different direction.
Check the dimensions of your camera, tripod head or favorite adapter plate to insure that the lock will fit without interference. You can always adjust the dimensions or the mounting hole positions to accommodate your setup.