Can be attached on a housing/lens port equipped with standard M67 screw mount

“XD Mount" for one-touch lens attachment and removal
The newly developed "XD Mount" enables one-touch lens attachment and removal. The "XD Mount" on a lens provides high durability, thin design without compromising lens optical performance and speedy lens attachment/removal in combination with XD Mount on housing side which has reasonable price and anti-slip lock function.
 
Features
A close-up lens designed to provide comfortable high magnification and longer working distance to fill light easily. Exclusively designed for underwater use to strive high image quality and using HR lens attains significantly compact lens body. The UCL-90 widely supports from a macro lens for full frame SLR system to a compact digital camera.
 

Compatible Lens
A telephoto macro lens with a minimum focus distance longer than 20cm is recommended (*1)(*2)
Using short minimum focus distance lenses will reduce the magnification.

(*1) Vignetting may be observed depends on the distance between master lens and lens port glass and/or UCL-90 and lens port glass.
(*2) Only usable when the focal length is between 60mm and 100mm range at 35mm film equivalent. Beyond this range, there will be vignetting at the wide side and deteriorated image quality at the telephoto side.

 
Powerful magnification with focal length 90mm (+11 diopter).
The maximum magnification when using this lens with 100mm range macro lens for a full frame SLR system is x2.23 (area ratio x4.98) (*3) which delivers middle power in between "UCL-67 M67/UCL-67 LD" (+15 diopter) and "UCL-165M67/UCL-165 LD" (+6 diopter).

(*3) When using for AF-S VR Micro-Nikkor 105mm f/2.8G IF-ED.

 
While the UCL-90 delivers high magnification, it still offers long working distance. When using with 100mm range macro lens for SLR, working distance is 52mm (83.4mm from housing port surface) at minimum focusing distance (*3).
Together with its compact size, the lens supports friendly lighting even at minimum focusing distance.