The 45 degree Viewfinder extends the eyepoint without changing the viewfinder image size (as when viewing the camera’s finder directly, i.e. by x1.0) so that 100% of the camera's finder image can be seen without vignetting even when viewing through housing/mask.
The eyepiece is positioned at a 45 degree angle relative to the camera's optical axis which helps in shooting situations like imaging a small subject on the sea bed, by enabling the diver to keep their body off the ground and head at a more natural position relative to the housing. Also the eyepiece rotates 360 degrees to help when shooting vertical compositions, especially from low angles.
Anti-reflective multi-coated glass optics for high light transmission and a bright, clear viewfinder image. Lens construction: 4 lens groups with 6 lens elements.
Please note that a Hugyfot housing is pressure rated to 100m when equipped with the standard viewfinder. When equipped with the Inon viewfinders, the depth limit is reduced to 75m.