Font DPI and screen scaling

[test]

On Sun, 2020-06-07 at 22:39 +0200, Frank Steinmetzger wrote:
> [...]
> In your valued experience/opinion, what is the appropriate way of
> ensuring
> that a 10 pt font has the same physical size on all screens if I use
> display
> scaling exclusively? Is a screen scale of 100 % assuming 96 dpi?

The only way to do that is to use displays that have the same amount of
dots per square(!) inch.

What do you mean by "screen scaling"?  I guess you could use a beamer and
use different sizes of canvas to project upon, but that probably doesn't
really count.  I imagine a 4k beamer that could project a decent image in
daylight or near daylight conditions at interesting distances would have to
be really loud because it would have to put out rather substantial amounts
of light which requires cooling, let alone expensive.  There's a reason
that people in cinemas have to remain in the dark during the show ...

I've sometimes used a magnifying glass, but that's kinda awkward, too.