“Arm’s Length,” Erin Shirreff’s first show at Sikkema Jenkins, presents a cohesive body of sculpture and photography that builds on the artist’s ongoing investigations into the overlaps and interactions of these mediums. Three new “Drop” sculptures show what paper studio scraps look like when translated into thin sheets of rolled steel hung on rods protruding two to three feet from the wall. Shirreff’s “Relief” photos of her own maquettes resemble oversize, vertically oriented magazine spreads. Also on view are four long-exposure photograms of geometric shapes (arches, circular cut-outs) that echo the three-dimensional works nearby, as well as tableaux made up of plaster objects arranged to look more like Surrealist landscapes than tabletop still lifes.