Ikelite FL Flat Port For Lenses Up To 4.5 InchesIkelite FL Flat Port For Lenses Up To 4. 5 Inches 5505 Ikelite Product Number 5505 Flat ports are recommended for standard, macro and telephoto lenses. Due to refraction, flat ports reduce the angle of coverage of a lens and magnify the image. This makes the flat port ideal when using standard, macro or zoom lenses to shoot small subjects. Note that if a port is long enough to accommodate the full length of a 1: 1 macro lens, the lens may vignette