Is there any practical difference between a webcam on suitable mounting and a document camera or visualiser?
This is a well worn topic but laced with less helpful information from manufacturers who are ultimately aiming to shift product.
To my mind a document camera is just a camera on a mount allowing it to give a top down view. At minimum it needs to stay in focus on paper enough that you can read or photograph it. I think you are just paying for the mounting arm letting you get a top down view and otherwise using a often quite low quality camera. But perhaps someone more enlightened can re-educate me.
I realize this is a hard question to answer objectively but is there any reason to have a dedicated document camera rather than a plain old webcam or phone on an adjustable mount?
What are the competing considerations that could turn this from a subjective question to something more objective?
For example, A webcam aims to show your face for teleconferencing and focus on that and its movement. The focal length and depth of field requirements could be different enough to justify specialisation.
The internet rumourmill also has it that webcams are well behind smartphones and digital SLRs in terms of quality due to the nature of the market. SLRs aim for quality and mobiles are competing with each other in a faster moving market and so allegedly improve more quickly.
Put it another way if you already have a decent webcam and a spare mounting arm would you be better off purchasing a document camera / visualiser or a second webcam for the 'overhead' work?
Consider a content creator who wishes to make a mix of face to face exposition anddemonstrating experiments handicrafts or music. What are the critical features that a camera should have to make it good in each field? Are there any fundamental trade offs?
The aim is to avoid guessing in the form of buying cameras and sending them back if they don't have good results. Its not good for you, the planet or the manufacturers unless that is the specific aim of your videos of course. While there are plenty of reviews of webcams and document cameras there are not so many that review one for use as a the other.