Wow, essentially an extraordinarily large view camera built around a repurposed lens, then converted into a depth-of-field adapter[0] in lieu of a digital back.

Wow, essentially an extraordinarily large view camera built around a repurposed lens, then converted into a depth-of-field adapter[0] 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 same focal length and aperture but a smaller image circle, and that lens were swung around in a spiral to 'paint' the same area as the episcope lens image circle, the two lenses would produce the same result, only the episcope lens can do it all at once instead of needing multiple exposures. [0] https://en.wikipedia.org/wiki/Depth-of-field_adapter https://en.wikipedia.org/wiki/Depth-of-field_adapter [1] https://en.wikipedia.org/wiki/Brenizer_Method https://en.wikipedia.org/wiki/Brenizer_Method -- [a] Annoyingly, I still don't know a satisfying explanation of why depth of field depends on subject/background distances, aperture, focal length, etc. The formulas exist, but every attempt at intuitive explanation I've seen has been incomplete or incorrect. Here's some videos to show those who say that longer lenses have shallower DoF solely because reframing by standing farther away from the subject causes the background and its blur to become relatively larger: https://www.youtube.com/watch?v=7xHMOzZM2ts&t=38s https://www.youtube.com/watch?v=7xHMOzZM2ts&t=38s https://www.youtube.com/watch?v=RkTaMyatsTo&t=116s https://www.youtube.com/watch?v=RkTaMyatsTo&t=116s (One's a $1000 Nikon bridge superzoom with a 4.3-539 mm (125x) f/2.8-8 and 1/2.3" sensor (5.6x = 24-3000 mm). The other's a $200000 Fuji box lens, 8.4-900 mm (107x) f/1.7-4.5, for 2/3" sensors (3.9x = 33-3540 mm). They fight crime!) Huh, found a DoF simulator that seems physically accurate at least: https://dofsimulator.net/?x=FDgBkATiAAAAJU4kcF3TgAA https://dofsimulator.net/?x=FDgBkATiAAAAJU4kcF3TgAA -- Other cool unconventional imaging projects: - forum thread for DIY DoF adapters going back to 2003 https://www.dvinfo.net/forum/alternative-imaging-methods/17195-homemade-35mm-adapter.html https://www.dvinfo.net/forum/alternative-imaging-methods/171... - very similar project to this one, using a reflecting surface rather than a screen https://www.youtube.com/watch?v=0ZixDTrQdzo https://www.youtube.com/watch?v=0ZixDTrQdzo - flatbed scanners as large-format camera backs, focusing on resolution instead of bokeh https://news.ycombinator.com/item?id=649150 https://news.ycombinator.com/item?id=649150 - telecentric/hypercentric lens https://www.youtube.com/watch?v=iJ4yL6kaV1A https://www.youtube.com/watch?v=iJ4yL6kaV1A, photolithography via microphotography by view camera https://www.youtube.com/watch?v=YAPt_DcWAvw https://www.youtube.com/watch?v=YAPt_DcWAvw