The artist Karen Rifas says she got the idea for her latest show, “Strung Out,” at the Bernice Steinbaum Gallery, when she was working with the strings she is (up to this point) best known for — those woven with oak leaves, forged into room-size installations. She decided to leave the leaves behind (although, to be accurate, she has done so before) and work with only the chords.

Using only this most simple of material — string or chord — colored in various shades, Rifas made sculptures fitted to various parts of the gallery that play with perception and illusion, geometric grids that are lovely and fluid — and without any technological gimmickry. By studying the space and the way the lines would interact with it and with each other, for months — and with maquettes (small versions of the sculptures) — Rifas came up with an amazing maze of works. You can walk into some of them and view them from different angles at different sides of the gallery, all the while the sculptures seem to move and transform, even change color. It’s deceptively complicated, as underneath these are chords hung from wall to wall, ceiling to floor and that’s it. It’s the real understanding of space, geometry and perspective that makes “Strung Out” one of the best shows up this fall.

Also back to basic beauty: John Sanchez’s paintings at the Dorsch Gallery. Sanchez is a painter, plain and simple. There is no video here or multimedia installation or soundtrack. It’s all brushstrokes. What will likely jump out at the viewer, first and foremost, is light. His imagery hasn’t changed much throughout the years, which is why the emphasis is on the details. He recreates a realistic twilight world, often just after a rain, so the reflections on the ground — in puddles and wet concrete — and the light peeking out from the clouds, become the focal point. One painting, in particular, on the left wall of the entrance must be seen, rather than described.

“Strung Out” by Karen Rifas through Oct. 29 at Bernice Steinbaum Gallery, 3550 N. Miami Ave.; www.bernicesteinbaumgallery.com. “John Sanchez: As They Are” through Nov. 12 at the Dorsch Gallery, 151 N.W. 24th St., Miami; dorschgallery.com.