I've been shooting with a Sony RX100VII in a Nauticam housing, Wet lens WWL-1 with Keldan 4x lights for a year now. While quite nice, I'm moving on an upgrade. First decisions already made, Sony A7s3 and Nauticam housing. Camera in hand and Housing on order. I'm keeping the Keldans. Ah but the lens and port configurations, I think I know but I'm tossing this out to see if I missed something.
First, I shoot video, no stills. I really hate guessing what to set up for a dive, macro, wide angle or fish portraits. I gravitate to fish portraits, simplest setup, IMHO. Another reason I'm changing is I want to shoot with natural light and white balance with no lights, because I'm working at capturing creature behavior and besides bubbles, light also seems to spook those that are indigenous to the deep.
I see 3 roadmaps, a prime wide angle solution, a macro solution, and a wide angle zoom solution. The macro solution is really its own purpose setup and I will move that direction later, I think, unless someone says its great for fish portraits. Now the wide angle zoom, while offering the greatest UW flexibility it is 6 times the cost of the fixed prime solution. (Sony 28-70mm w/Wide angle conversion-WAC-1). I may go there one day but not his year.
So on to fixed primes, I'm looking at a 28mm f2, 35mm f2.8 and 55mm f1.8. Most info I have gathered say the 55mm is like stuck in the middle, possibly fish portrait only, I understand. The 28mm and 35mm can both be set up to mount a WWL-1(which I own, already) Because of that I'm leaning to the 35mm which if needed the WWL-1 could hauled down below for a reasonable wide angle shot. The 35mm seems to be a bit of a compromise to fish portraits but clearly not as wide angle as the 28mm, but will do a better job of filling frame with the subject. Ultimately weight is also a consideration, luggage and air travel to distant worlds, well maybe again in 2021 or 2022, sigh. The Caribbean is relatively open and I've been this year and going again in late november. The point being I may not even carry the WWL-1 because of weight and limited use. So my thinking is getting the 35mm with a flat port and jump in.
Observations and thoughts are welcome.
Fair winds and following seas.