Back from 8 dives in two days around Tioman, Malaysia, and more A1 field tests.
Diving was great, viz was excellent (25m+ some days), weather was fine, camera was/is still a challenge, though I'm learning how to treat her better now. I bought a 26" Samsung LCD HD TV yesterday to watch all the footage 'as technology intended', and am now running the TV as a second monitor on my quad - really nice set up for editing and viewing picture quality, transitions, colour filters etc B)
So the camera:
This time I did not use a CC filter at all, but rather WB'd off a 'warm' slate. This was excellent whenever I could get a good WB - usually in shallow water below 7 metres. The quality of the HDV material when light is abundant and the manual white balance completes its cycle is excellent. I used both WA converter and also no converter. Again, in bright shallow water - no issues.
I also used lamps -both a halogen and an HID (used separately, different colour temps etc), and both during the day and at night I got good manual WB, and good colours. (I was using the HID on loan prior to possible purchase, and I'm so glad I did - the hot spot in the middle of a WA FOV even with diffusers was unusable - won't be buying that one !)
The lack of a CC Filter made a huge difference to the light getting to the camera, and my footage from this trip is leaps and bounds ahead of my Bali trip a few weeks ago where I used a 'magic' filter all the time.
The main challenge came with trying to WB an any real depth, and I don't mean deep! Below about 7m (23 feet) I had hardly any luck performing a WB. The WB icon just kept flashing. I tried this time and time again on both sunny days and overcast days so this was not a 'one time failure' - consistently I could not get the damn thing to WB! On the bright days with viz over 20m the water seemed crystal clear and STILL I couldn't WB below about 8m even pointing to the surface! I was really amazed - this without filter OR WA converter on a couple of dives.
I'm not sure what the camera does for WB when the icon is flashing. Whether it then continues in auto mode, or at the WB setting it was last able to get a 'fix'. Nevertheless I got my worst grain/artifacting in the dark areas of a shot when the icon was flashing and the light was less than brilliant. The artifacting was again a psychedelic red flecking, and with no CC Filter on I can only wonder where the red came from 
Here is another observation: when I knew I was going into 'dark' water and wouldn't be able to WB at depth, I WB'd at 6m and then did not touch the WB control at all. This gave me pretty good results, EVEN when the light was quite poor. We did two wreck dives on an old steamer at 27m (89') and although the colour saturation left something to be desired, I shot a bunch of stuff under plates, on the dark side of the wreck etc, and got no real grain, and no artifacting at all - in fact under these circumstances the 'low light' capability seemed to be pretty much what I'd expect with the TRV950.
One test I didn't get round to doing on this short trip was to forget the manual WB, and let the camera role with auto WB the whole time. It seems that I got my worst grain and artifacts when the cam couldn't get a WB fix.
I'm off to video whale sharks at Donsol in the Philippines in a couple of weeks and will try manual and auto WB and a couple of other tricks, but I think I have the measure of the A1 now - not an FX1 by a very long shot, but a very convenient HDV camera that can produce excellent results when it is nurtured....
I’d be very interested in others’ field experiences with the A1, especially relating to WB and low light. I have not heard of anyone else having these challenges – maybe my camera was built on a Friday? 
It would be reassuring to know that my observations are reproducible on other A1 cams!
