It has to do with LaTeX and emacs in intent.

LaTeX: accomplished typography emacs: control of the interface

It delivers.

The name is weird, the project is sound :-)

Superior to LyX: fully WYSIWYG, no limitation on what it can do.

On the other hand, you do get the full (La)TeX ecosystem to draw on. If I want to draw a commutative diagram, I can add tikzcd to the preamble, and insert inline TeX to do so.

There is some support for the LaTeX ecosystem from within TeXmacs. If you want a TikZ drawing, you can insert it programmatically into a TeXmacs document in a seamless way---if you have the same font for your TeXmacs document and for LaTeX it will be nicely integrated as far as I know, You can see the blog post https://texmacs.github.io/notes/docs/embedding-tikz-figures-...

I use it for all of the pedagogical material I distribute to my high school pupils. It allows me to type quickly and accurately math and explanation with exquisite typography. It allows me to edit freely and with total ease what I have already written: I don't have to look for the point where I have to edit because it is WYSIWYG.

I do not have to collaborate with anyone in writing so it does not matter that there are no users among my colleagues.

In my opinion it is superior to all other systems I tried (I tried many and a lot, and all of the main ones). And, importantly, it is equal or superior to the other systems in _all_ respects.

I would rather use TeXmacs, it frees you from the write-compile cycle while being equivalent (maybe in some ways better) from the point of view of the control you have on the document and the typographical quality.

There is also a wide choice of output formats.

In addition to making it possible to write easily, TeXmacs is also based on a markup language. It demonstrates that a markup language and WYSIWYG writing can coexist efficiently.

> Only Adobe InDesign provides a comparable implementation, tweaking all those details.

TeXmacs claims to have implemented microtypography as well (https://www.texmacs.org/tmweb/home/news.en.html, as I am reading it, in the opening paragraph on version 2.1)

> assuming infinite resolution

this is an assumption that goes against the concept of "f-number" so if one does it, they should not expect to get to anything sensible.

I just meant sensor pixels, because you’re obviously losing those when cropping, but you get the same perspective as from larger focal length (since you’re not moving).

I agree that the images correspond to the same region in object space. Further assumptions on optical resolution don't work well, as the optical resolution depends on the f-number.

The angular resolution depends purely on the aperture diameter, not the f-number. There should be no difference between capturing the image in high resolution, and blowing it up for a lower resolution sensor. All that should be needed is a 200mpx sensor that can output the entire frame in 12mpx, and 12mpx of the central area in full resolution. It's similar to how our eyes work.

I expect depth of focus to be different.

It will not, I specifically included the F-stops for that reason.

The depth of field is determined by the focus distance and the aperture of the lens. Both remain unchanged.

Note that 35mm F/2.0 is the same aperture as 70mm F/4.0. Both lenses have an aperture of 17.5mm. (35/2.0 == 70/4.0)

You can easily verify this with your favorite zoom lens. If you have an 24-70 F/2.8 available to you, you can verify by taking 2 pictures; one at 35mm F/2.8 and one at 70mm F/5.6. Crop the 35mm one to 25% area (half the width, half the height). Render both images to the same size (print, fill screen, whatever) and see for yourself.

Yes, depth of focus will be larger, as signified by the larger f-number.

There is some support, but I do not know the details. You might try and ask in the TeXmacs forum, at http://forum.texmacs.cn/; a few of the developers read it and answer questions and they might have the information you are looking for.