"A unique tool designed to reveal beautiful details hidden in tight spaces, the direct-view Sony E-mount 18mm f/8 Macro Probe Lens from AstrHori features a 2:1 magnification ratio and waterproof probe extension with front-end illumination to bring the unseen world to light. The 2x magnification capability enables detailed close-ups, while the extension's slender, 0.9" diameter makes it ideal for fitting through slim openings and into small spaces. The optical structure consists of 23 elements in 17 groups and features an aperture range of f/8 to f/28. Taken all together, the wide-angle macro provides a broad depth of field that brings both the subject and its surroundings into focus for environmentally rich imagery."