RX100 recommendations/advice

I recently bought an RX100VA (as an upgrade to my gopro) for an upcoming dive trip to Palau and I was hoping to get some advice and recommendations from sony users... Ive spent a few weeks learning the ins and outs of the camera but unfortunately I live in Chicago so all of my testing has been done on land. I have the camera, housing, tray, kraken hydra 2500 (combo video light/strobe). I decided not to get a wide angle or macro lens or an intricate light setup just yet as I want to test the rig out first and make sure I like it enough to invest more.  I will be doing mostly video, but also definitely interested in some stills.

I would love to hear your thoughts on any or all of the following:

White Balance: It is my understanding that white balance is one of the major drawbacks of using this camera underwater, im curious what you have had success using? I planned to use auto or underwater auto, unfortunately Im not comfortable enough with my diving ability to be messing around underwater with cards trying to set a manual white balance...

In addition to white balance, would you say that a red filter is an absolute necessity? And if so, is there a specific one you could recommend (for a 67mm thread)?

Picture Profile: One of the reasons I liked this camera was for its ability to shoot sLog2 (this was before I realized the minimun iso for sLog2 is 1000)... I am proficient in PremierePro, Davinci Resolve, Photoshop etc... I was wondering what picture profile and sub settings youve had success with? Also, do you use any luts made specifically for underwater, or have any general color recommendations?

Autofocus: Regular AF-C seems to work incredibly well on land, but I have read that it can be difficult underwater. Which AF mode/area do you prefer?

Metering: Is the normal matrix/multi metering ok for underwater? Or do you prefer spot metering?

If there is any other insight/tips/suggestions you might have I would love to hear it.

Thanks!

I've been using an RX100iv in a Fantasea case (about 20 dives) and an a6500 and a7RII in Seafrog cases (about 70 dives).

I have a couple of Z-330 strobes that I use for macro and close-in shots. They're attached to 18 inch arms, and that's fine for what I do. For so-called wide angle shots, I need to get the arms further out, otherwise backscatter overwhelms the shot. For wide angle, I shoot with ambient light. I tried a video light once, but quit because of backscatter.

I've shot S-Log2 video with my a7RII and color graded in both DaVinci Resolve and VegasPro. The results were on par with what I got just using Program Auto Exposure and standard post-processing. Underwater scenes can change quickly if you're looking around to frame and/or follow interesting targets. That means a lot of color grading in post, even within the same clip.

Yes, white balance is a problem. Setting up a white card for all the shots you'd like to take at a specific depth is problematic, especially on a group dive where you have little enough time to take the shot, let alone perform the WB preliminaries. I did try a red filter once, but found the net intensity level too low. The filter passes red light, of which there is very little at depth, and blocks blue-green which is predominant. I'd rather work without the filter to get enough light for the shot and post process. Of course, if you have a video light (that simulates sun spectrum) and can manage placement to minimize backscatter, then a red filter may be helpful to get that bit of extra WB tweaking; but again, you could handle that in post.

Back to the RX100iv. The big problem is battery life, especially if you use the on-board flash for TTL. I recommend changing the battery for every dive. I ignored this advice in Palau and ran out of battery on the best shark dive of the trip. In my opinion, opening the case and the camera on a dive boat would be worth the risk. Battery life caused me to switch from the a7RII to the a7RIII recently.

I also forgot to take slow motion shots of mantas with my RX100iv in Palau.  Another diver did that with a GoPro in ambient light and the results on that little screen were stunning.

Palau, thousand islands. Shot from 2-person Cessna, 45 minute tourist flight. My door removed to eliminate shooting through a plastic window.

Palau, German Channel. Ambient light.

Palau, Japanese Zeke floatplane shot down in WWII. In about 30 ft of water. Ambient light.

Palau. Ambient light

Papua New Guinea. Nudibranch. 90 mm Macro. Z-330 strobes, TTL.