The Composer Pro II with Sweet 35 Optic is a 35mm f/2.5 selective focus lens with a 12-blade adjustable aperture. This lens adds unpredictable depth and movement at 35mm, so you can hone in on the details that matter most. Place the sweet spot of focus anywhere within the frame by tilting the lens, perfect for illuminating a face or bringing out a specific detail in your landscape or environmental portraits. Aperture ranges from f/2.5 through f/22. Along with controlling depth of field, aperture controls the size of the sweet spot of focus. Brighter apertures produce a smaller sweet spot of focus with more dramatic blur and darker apertures give you a larger area of focus with less blur. Sweet 35 Optic is part of the Lensbaby Optic Swap System.