What technique did Rembrandt use in his Self-Portrait to make the main figure appear to emerge from the dark background as if it were lit by a spotlight?

i think it saint james in santiago de compostela

there are three basic steps required for fabric production. the first step in creating fabric is yarn production. here, the raw materials that have been harvested and processed are transformed from raw fibers into yarn and threads. this is done by spinning the fibers. spinning can be done by hand, but this process is quite tedious and time consuming. these days, the vast majority of spinning is done by spinning wheel. the fibers are drawn across the wheel, and as it spins, the fibers are collected on a cylindrical object called a bobbin. the bobbin holds the spun fibers, which are now connected into a long strand of thread or yarn. in the next step, the bobbins will be transferred to another machine, where the yarn will continue on its journey into fabric.

after the raw materials have been converted into yarn, they're ready for the second step in the production process, which involves joining these individual threads together to form fabric. this process of joining the yarn together is called weaving. weaving is done on a machine known as a loom and requires two sets of yarn. the first set, called the warp set, is strung tautly across a metal frame. the second, called the weft, is connected to metal rods, with one thread per rod. the loom is controlled by a computer, which lets the weft know how the fabric should be woven.