Hinge tracker

For taking picture of the sky is mount of the camera maybe more important, than camera itself. For long exposure, for sure. Cheap and portable solution could be hinge mount or hing tracker. Several of such mounts are at Gary Seronik website.  Other name is scotch mount [2] or barn door [2] tracker. One can actually rotate by hand with reasonably good results. Interesting is also auroracam.