I have just recently recived my new M67 x 3 Macro / Close up lens for my underwater camera housing.
Basically for compact camera users we have 'wet lenses' - both macro and wide angle - that we fit to housings to increase the capabilities of our camera.
With my new x3 macro lens it helps to increase the magnification of my image by x 3 and you can stack (add) lenses to increase the magnification.
Also with these lenses the camera takes a photo of the 'virtual image' on the lens rather than the real life image.
Dendordoris denisoni nudibranch
Cardinal fish with eggs in his mouth