An action camera is a deep focus camera which does not require focusing but prevents a subject gets in focus in close range (within 60cm/2ft range in theory for GoPro® camera) thus not usable for underwater macro shooting. Using standard macro lens for a compact digital camera would not help the situation as it would create vignetting and very shallow depth of field preventing comfortable focusing. The UCL-G165 SD lens is so-called "wide close-up lens" specifically designed for action cameras based on their optical characteristic. The depth of field (DoF) underwater will be 5cm/2.0in to 35cm/1.1ft when using the lens for GoPro® HERO7 Black supporting closer minimum focus distance underwater to capture wow photos/clips.
The depth of field (DoF) on land is theoretical value based on focal length/aperture of camera lens and pixel pitch of the image sensor. DoF underwater is measured from "the forefront of the lens".
Ideal Angle of View for Macro Shooting
Maximum angle of view of GoPro® HERO7 Black Black is approx. 151° on land which will narrow down to approx. 94° when the camera is housed in genuine dive housing and submerged due to different refraction index. The INON UCL-G165 SD slightly increases angle of view underwater to 110° to capture dynamic scene played by a subject as the lens frames subject larger than UFL-G140 SD which delivers ultra wide 140°.
Measured angle of view by INON on land or calculated angle of view underwater based on the measured angle of view on land. Not confirmed by camera manufacture. The measured angle of view of "HERO3+ Silver Edition" is approx. 142°(air) which is less wide than the "Black Edition". So angle of view underwater with this lens is less than 110°. The "HERO3+ White Edition" has not been tested.
Professional-level Image Quality
Optics is constructed of 2 elements in 2 groups. All elements are made from high refractive index glass lens to minimize whole size dramatically without sacrificing performance. Both lens elements have anti-reflection coating on all surfaces to elicit combined master lens performance with less ghost/flare.
Speedy Lens Exchange by SD Mount
Bayonet INON SD Mount compatible to support friendly and speedy lens exchange underwater. Compatible with AD Lens Holder to hold a lens when not in use.