Conclusion improve color fidelity:
Depth 0-5m: reddish, good only to achieve a color effect (intentional?)
Depth 5-15 / 20m: works exactly as hoped (see photos)
Depth> 20m: Advantage: the blue is richer (stronger) downside: the image (whether video or photo) is slightly darker
Not cheap, but in areas where work still enough natural light available is impeccable.
When using underwater lights of the filter brings only limited what, because the artificial light takes so looks really quite a bit of color back into and through the filter's image is the red part may again be dominant.
Let's go back about real glass:
The packaging was a bit of "Iridium Edition" and "Red Filter 2.0"
In detail, it was said:
- Lens 10x stronger treated (in the sense of more resistant)
- Iridium acrylic delivers precise color correction
Whether that's true now I can not judge, had "only" this version and not a direct comparison to the 1.0-genuine glass variant.