Hi Barry: Thanks for your helpful answer!! I see above that you prefer to shoot in 2.7K in Protune mode with both medium (127 degree), and wide ( 170degree) FOV . After all the video you have taken in warm clear water what setting give you the sharpest and best resolution video, and also which gives you the best 3D effect
when seen on the big screen. I have a 50in Panasonic that is my acid test. Do you ever shoot 1920x108060P in Protune?? I have a modified Gates Housing that I always shoot 1080P60 with a Panasonic triple chip camera and the results are excellent, however I have to do a bit of a run around using the program MuliAVCHD to process after rendering in Sony Vegas 10E so the footage can be seen as real 1080P60using the AVCHD 2.0 protocol. The newer Panasonic and Sony blue ray players accept this.
IMO, 2.7K gives you the very best the 3+ Black has to offer. I always end up rendering it as 1080 29.97p, however. Downscaling the 2.7K I think gives a better result than shooting in 1080 natively. In 2.7K, mode more of the sensor is used. It's really the sweet spot of these cameras. Again, just my opinion. As for the 3D effect, this much depends on how you set up your shot. The best 3D comes from distinct foreground, middle, & background elements. In order to get good negative parallax- aka popout- you need to have foreground elements at 4 feet or less from the port. This works very well for fish. At over 4 feet, or so, you'll still get a very good sense of depth, kind of like looking out a window, but you won't get the popout type of 3D. Of course, you can't expect that in every scene anyway, nor should you. You mentioned that you once tried a Sony TD10 but didn't like the narrow FOV. My standard setup is the GPs mounted on a JVCTD1 housing. The TD1 also has a very narrow FOV, but, when used well, can also have advantages. It's actually somewhat easier to get strong negative parallax with it than the wider FOV GPs. But, the GP picture quality at that 2.7K mode runs circles around the JVC and has a MUCH better dynamic range with far fewer clipped highlights as well as being progressive as oppossed to interlaced. (I'm not a big fan of interlaced) The other advantage to shooting at 2.7 is the cropping potential. You can crop quite a bit and still come out with true 1080 res. The only negative about shooting at that res is that when the files are paired- I use Edius as my NLE- the timeline really bogs down, so realtime smooth playback is just not in the cards. But, its worth it and there are workarounds.