Very true but underwater seems to always be a compromise (besides staying alive and not losing your buddy). Having the right lens, juggling buoyancy and distance to subject, AF for subjects with no discernible eye, being close enough to fill the frame but not to spook the subject, managing surge and particulate are a pain and of course the challengeMacro lenses that externally extend are unfortunately a no-go underwater because you're using a flat port in front of the lens and you a) don't want to have to use a giant port with all that buoyant empty air space for extension, and b) you don't want that distance between lens and the end of the port changing much and screwing with the image optically.
The other quirk of shooting macro through flat ports underwater is that the flat port combined with the water has a magnification effect due to light travelling differently through the flat glass port vs the water, so with a 100mm lens the image your camera sees on the port looks more like it was taken at 125-130mm than 100mm. Just like when you're looking through a flat glass mask underwater and everything looks bigger than it is. Another reason why there is a demand for quality sub-100mm macro lenses in this field for certain types of subjects.
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