Antique 4x5 camera creates 20 micron photolithography masks: Super tiny tax form

There is a great video on creating lithographic masks on Ben Krasnow's Applied Science channel - link to this video The photographic steps are pretty accessible.

Oops, second vid should be from Ben Krasnow’s (bkraz) Applied Science channel: link to this video Ben explains somewhere in there that this was done to help create a better substrate for the first experiment.

I recall this but don't remember seeing anything smaller being posted. Sub 100nm for a hobbiest would be pretty awesome. link to this video

Wow, essentially an extraordinarily large view camera built around a repurposed lens, then converted into a depth-of-field adapter0 in lieu of a digital back. There's actually a known technique for taking wide angle photographs with depth of field this shallow using only a typical long lens:1 stitching together frames to build a wider field of view is all that's needed; long lenses all have shallow DoF by nature.a This interestingly can also be used to explain why the episcope lens has such shallow DoF: its focal length of 432 mm would make it a super telephoto lens, yet its large image circle means it has a wide-angle field of view. If it were replaced by a telephoto lens with the sam…