I'm a big fan of the magic, but I'm not sure it always makes a big positive difference at the very shallow depths that we often see mantas.
The first of the following images was also shot at Nusa Penida Manta Point, a few months ago, using the Magic Filter. I liked it that the filter helped bring out the reddish brown color of the cliffs (which were brightly illuminated with the morning light) on the undersurface of the water. But the underside of this manta badly needed some fill flash, which I obviously couldn't do with conventional strobes. It was this shot that has pushed me to try to solve the problem of fill-flash with red-orange filters, on which subject I'll post again later. But back to Manta Point, most of the shots from that session suffered from the viz, which was - as usual for any manta site - very poor. It isn't that noticeable here, shooting upwards from very close with the 10.5, but in any shot with any sideways distance in it, the mantas just disappeared in the mist.
I think viz is by far the most important factor separating ok and wonderful manta shots. The second image was taken at the "Manta Point" off South Komodo last year, without the Magic Filter. Usually the viz at this site is like pea soup, but that day it was phenomenal. I'd never really been able to see the reef before! What the mantas were doing still hanging around with nary a piece of plankton to eat for miles and miles, I really can't say, but they did look gorgeous.
The third image is from just a few weeks ago, at Karang Makassar in Komodo. This is the site where a huge aggregation of mantas sometimes forms to feed on the rising tide. In 2003, we counted more than 80 mantas in one pass here. Not quite so many this time, maybe 50. Didn't use the magic filter this time, but at surface depth I don't think it mattered. This aggregation only occurs when there is plankton to feed on, however, so it's unrealistic to ever expect the brilliance and sharpness that was possible that gin-clear day at Komodo's Manta Point.
All images taken with the 10.5, Fuji S2 for the first two, D2X the last.
Frogfish


