how much light is lost with a Magic Filter?

Any one know how much light is lost with the Magic Filter and Auto Magic Filter? I have a Nikon 8400 which can shoot raw and has limited WB adjustments (6 or so presets).

I would be inclinded to get the Auto filter, but am afraid I will loose too much light as I don't like to shoot above ISO 100. Most of my diving is between 30 and 60 ft (10-20m) in the blue waters of Maui and Lanai.

i would say its probably about 2 fstops (just guessing here)

in shallow tropical waters like where you shoot you will be fine. f4 instead of f8 for instance

A lot. I'll go with Mike's guess of 2 stops. That's the downside of the filters. You will shooting wide open. You might still need an ISO boost to 200. Plus, shooting toward the sun makes bad shots.

The Auto Filter is stronger that the original magic. When we measured them in the house the Original lost 1.3, the Auto-Magic lost just less than 2 and the Green Water lost 1.5 stops.

Sounds like the original is a better bet for you. Assuming you want to set the WB manually.

Alex