Questions about video that are also relevant to still photography. Questions about video should be asked at the "Video Production" sister site (at video.stackexchange.com).

Questions about video that are also relevant to still photography. Questions about video post-production and other video-related topics that are not relevant to still photography are considered off-topic. They should be asked at the Video Production sister site.

See Can I ask Videography related questions? for the community discussion on the topicality of video posts. The top answer there states:

I think the important thing here isn't the equipment but the intention.

For example, a question about 24fps vs. 30fps strikes me as off-topic. A similar example would be audio. Both of these are irrelevant to still photography, regardless of what's behind the lens.

On the other hand, lighting questions have a broad overlap, as do filtering, or questions about exposure and composition generally.

I think if the only relation to still photography is that it's using a DSLR body more typically used for stills, that's probably _not quite enough to make it on topic. I think the best rule of thumb will always be:

Can I use this information in still photography?

Lighting, yes; composition, usually; audio, no; lenses, yes... It seems to work quite well to me.