Well that's a good question. At the moment I only have an Aquatica +5 Wet Close up lens. I was going to rely on the RX100’s inherent wide angle for video work, however I know a wide angle wet lens is highly recommended. Thing is I can’t really justify the $500 that a really good lens would cost at the moment.
I’m in the market for budget recommendations or a second hand lens that would do the job.
The Inon UWL-100 Type 2 though designed for 35mm equivalent camera is reported to work well with the RX100 and does not even vignette at 28mm
Considering that for video you will use the steadyshot in active mode the camera will be at 33mm because of crop so the lens will definitely be fine
The quality is excellent as it is achromatic and you can get it second hand on ebay, make sure you find the type 2. Even new this is less than $400 US
That's good input Interceptor, I'll start trawling eBay!