Why are printers, earplugs, and shoes on topic, but not video, graphic editing, or computer vision?

Question

We have this question about earplugs What kind of earplugs are best for concert photography?, which has remained open by consensus despite some interest in closing it as off-topic. There's also this lovely one about shoes: What kind of shoes are best for wedding photography?.

We also get a bunch of printer questions, like, recently:

• Why do professional printers still feature cartridges?
• Best way to avoid print head clogging when not using printer?

and these also generally get some back-and-forth on topicality.

Meanwhile, we've generally decided that questions about industrial optics without applicability to general photography are off-topic, as are questions about using cameras to measure things, and questions about video.

What's the difference here? Why does one category — stuff which is only peripheral to this light and optics and recording medium thing — get a pass, while the other does not?

Answer 1

Here's my take. We want this site to continue to grow are around a community of practice. In this case, that community is defined right first thing in the tour:

Photography Stack Exchange is a question and answer site for professional, enthusiast and amateur photographers.

A community of practice is a

group of people who share a concern or a passion for something they do and learn how to do it better as they interact regularly.

And that's basically the guideline I'd suggest.

• Is it relevant to the community of people interested in the art, science, craft, and business of making images with light? On topic.
• Is it instead using the same tools but really only connected through gear and not through the community of practice? Off-topic.

Through this lens (heh), some very similar questions may be on different sides of the line. That's okay.

Of course, there's often some overlap with related communities — astronomy, machine learning, etc. But for questions about those, the making photographs aspect should be centered, or else we should nicely redirect to a different Stack Exchange network site where the community of practice is aligned.

House painters and landscape painters both use brushes and paint, but those aren't the same communities of practice. Same here. It's possible that a house painter also does artistic painting as a hobby, but that doesn't mean the circles collapse: many people are members of multiple communities.

I've heard the argument that it'd be better to be more expansive, that we'd get more people that way. I think this is actually counterproductive, and it's better to focus on the concern for photography itself.