For example, this question was flagged as a possible candidate for migration.
Are general questions about tracking and the filming aspects of tracking on-topic here, even when not necessarily specific to blender?
In the past we've allowed general CG questions as long as they are not overly broad and/or deal with aspects specific to another program.
Some related metas:
In conclusion, I don't see any reason to treat tracking questions differently. If it's not not about blender, it's not necessarily not on topic.
I'm one of the mods on Video Production. Video Production already has a level of 3d graphics questions that get handled over there when non-blender specific. We'd shy away from something like making assets for a game, but, my personal feeling at least, is that anything that has to do with the production of a movie, film, tv show, stream, youtube clip, whatever, is on topic for Video Production. That can include anything from financing a production to producing effects shots to animation and modeling.
That said, I'm glad to see you guys handling some fringe stuff for general graphics since we do have a more limited set of people who are knowledgeable about 3d graphics on Video Production (I'm one of them), but just about anything you guys don't want can likely be funneled either our way, or game design's way if it is on the modeling for games side of things. Of course, the standard "don't migrate crap" and "check if it'd be a dupe" stipulations still apply.
My thoughts would be handle whatever you think you can/want to here, since you have a larger base of 3d graphics experts, but anything that doesn't fit that is film and video related, send it our way and we have some generalists that may be able to help.
In general we allow anything that has to do with video post-production (e.g. CG, Animation, especially in After Effects). The question about motion tracking would be very well on-topic for us. We actually have quite a few questions already about motion tracking and motion compensation.
We also allow questions about 3D, though if they go deep into 3D modeling, rendering etc. they wouldn't quite fit our scope. If its a general beginner 3D question it would be ok to merge. Though if you are ok with these types of questions aswell it might be better to keep them here as your users would have much more know-how in that area. We just accept them because so far there wasn't a better fit for these type of questions and they fit the area of video production in a way.
I think as a rule of thumb, if it can be done in or is about After Effects, Nuke etc. its ok to merge.
Hard to decide in general, but in this case the question is:
Has somebody tips about how to shoot a good video for motion tracking?
Tracking algorithms/detecting feature points are mostly identical in all motion tracking environments nowadays, so the question is more about planning a shot and that's not really Blender related (IMO). I'm sure this question could be answered here. But even if, it seems too broad for blender.se at the moment and sounds more like a 'drive by question' without any further details.
Since video.se allows broader questions like:
It probably makes sense for the OP (in this case) to migrate. Most important is that the user gets a solid answer, right? Why not wait a few days so our users have the chance to comment and answer something blender related and migrate it afterwards?