A dark sky will help, but is not absolutely necessary. Just open the shutter and wait a while. It is usually very clear after just a moment's thought why the telescope needs to have a drive for most photography. Another source of error, which is correctable to some extent, is misaligning the mount with the pole. This can cause field rotation even in a photograph that is precisely guided.
Polar alignment is the subject of another article.
If the field of view of an image is 1 degree, and it is recorded on 35mm film, this error will be as small as, or smaller than, a film grain. The result is that any error will not be detectable. Some mounts will give that accuracy without guiding. To be sure of good quality piggy-back images with those mounts, you'll need to guide. But the guiding requirements will be less stringent than for prime-focus work.