"and it is much easier to make a Porro binocular totally waterproof using individual focusing."
Please illuminate me with an authenticated example of this occurence. Perhaps a trifle fanciful?
I've only seen a figure or report of 20 minutes at around 1 metre in regard of a similar "waterproof" porro prism.
Cheers.
Here is an interesting review on a Fujinon FMTR-SX 7x50 by a fellow who can confirm they are waterproof!
by
Marc, Verified Owner from NC, United States Written on November 8, 2016
I first bought my Fujinon Polaris Binoculars over 30 years ago. Yes they are the same as today. While boating near Charlotte Harbor, trying to help a sail boat that had run aground. My 22' Aquasport was submerged after being dragged by the very large sailboat.
My Fujinons were under salt water for three days before I was able to get my boat recovered. Since these were the finest binoculars I had ever had I sent them back to Fujinon for repair. I received them back with new rubber exterior within 10 days with a letter that said that there was nothing wrong with them except the covering which had been scarred during the accident, so they put on new rubber and sent them back, and I used them another few years till I left them at a ball game watching my grandson. I tried MANY others, but none would give the visual picture offered by my FMTR-SX 7x50's. So I bought a new pair from OpticsPlanet which are the same fantastic binocular gas-filled rubber coated binoculars I lost and missed so much. Their price was the best I could find and the service was excellent. I am in the NC mountains now and the mountains views are wonderful with my new ones.
Marc Sharp at Boca Grande, FL, now Franklin NC. These are a Must-Have!!"