Capturing the world of ‘small’ requires a Macro Port, which can reveal amazing colors and behaviors of tiny underwater critters. Macro imaging begins at subjects about 2.0 in / 51 mm and smaller. Nearly all Gates Macro Ports utilize a simple flat element of acrylic, and occasionally glass.
Macro Ports allow the use of diopters, too. Sometimes called close-up lenses, they are affixed to the camera and allow imaging of even smaller critters with progressively stronger magnification (+1, +2 and +4 strengths most common).