which one is best for portraits? medium shot TTartisan 75mm f1.5 ,aka clone of Biotar the swirly bokeh king model to camera distance: 1.46m depth of field 3.1 cm blur 7.53% canon 85mm f1.2 model to camera distance: 1.65m depth of field 1.9 cm blur 10.67% btw, you can get even more exotic swirl bokeh from 900g russian helios 40-2 85mm flickr simon utak youtube sagittal astigmatism lensbaby nukepedia pencilofrays petzval home built
The toroidal superconducting magnet: The newly accepted toroidal field superconducting magnet, a D-shaped structure measuring 21 meters long, 12 meters wide and weighing 582 tons, is the largest fusion reactor superconducting magnet ever built, with 1.3 times the volume and three times the stored energy of comparable magnets in the International Thermonuclear Experimental Reactor. Sixteen such coils will eventually form a ring generating a 6.5-tesla magnetic field at the plasma center. During heat treatment of niobium-tin superconductors, a temperature deviation of just a few degrees can cause performance to collapse, and keeping temperatures uniform across a furnace holding coils more than 10 meters in size is itself a cutting-edge engineering feat. The BEST (Burning Plasma Experimental Superconducting Tokamak) is a compact, next-generation nuclear fusion device being built in Hefei, China, aiming to demonstrate actual deuterium-tritium plasma burning and generate the world's fi...