Waterproof Binoculars.......in the swimming pool!
Posted 27 July 2004 - 09:25 PM
I have had them for 6 months, the pool was clear and the water was just right. The sunny afternoon made for a perfect picture taking opportunity and my daughter was available to take the photos, so in I went. I had goggles on and had the eye cups folded down. Focus with these only gets as close as about 50 feet so optically testing them underwater was not the intent. I just wanted to see if they were waterproof. My wife is calling me to finish watching a movie now, so the results will have to be written later, but here is the photo.
I will say that the results were mixed.
Posted 27 July 2004 - 09:43 PM
Posted 27 July 2004 - 11:00 PM
During my test earlier today I sat on the bottom of the pool in water 5 feet deep (60 inches). The binoculars held to my eyes were approximately 30 inches or 2.5 feet below the surface of the water. At no time were they any deeper than 3 feet total. They were in the water no longer than about 30 to 40 seconds tops.
Upon coming out of the pool I did rather quickly note that the left eyepiece barrel was fogged up. The right barrel was fine. Upon rinsing the binoculars and investigating further the field lens of the left eyepiece barrel appeared fog. There was no evidence of water intrusion on the right side at all. There was no evidence of water or fog on the objective (interior) on the left side or on the prisms.
Upon further investigation and removal of the eyepiece assembly on the left, the water had to have come in around the perimeter of the eyepiece lens exposed to air. There was no water incursion between the eyepiece assembly and it's holder as the field lens of the eyepiece was dry. This would also explain the fact that the prisms were dry. The only water incursion is between the elements on the left eyepiece assembly. Apparently someone did not check the o-ring seals on this side. The eyepiece assembly itself (external barrel) has several o-rings, and they did there job.
All in all this design, as evidenced by a correctly executed right barrel appears to be pretty much waterproof. Unfortunately quality control did not catch the problem with the left eyepiece barrel.
See additional photos posted showing differences between the left barrel view and the right. The photo shows what happens when water seeps in between eyepiece elements.
Posted 28 July 2004 - 01:26 AM
Posted 28 July 2004 - 07:10 AM
In all seriousness, a leak test is an excellent measure of a binoculars robustness. But I wonder Barry, based on the above pictures you provided, would the chemistry of the pool have any play in ruining the optics? If so, would ocean water have a different effect?
Posted 28 July 2004 - 08:47 AM
I believe seawater would be far harsher on binoculars due to water evaporation and salt crystallization. Hence the need to rinse with tap water as soon as possible.
I believe any binocular labeled "waterproof" should be able to survive relatively brief total water immersions to a limited depth (I believe Fujinon specifies a time and depth limit, cannot remember what that is but something like 5 feet for 15 minutes.) I certainly would not be that confident at all in repeating this test with my "waterproof" binoculars which include 2 Fujinons, the Nikon Action Exceed 10x50, the Swift Audubon 8.5x44 and a pair of Canon 8x32 roof prisms.
As of this morning the left eyepiece barrel of the tested binoculars did have a uniform fog between the lens elements. My watch is running fine and my hair hasn't turned orange or green.
Posted 28 July 2004 - 12:01 PM
A very direct and interesting test.
Posted 28 July 2004 - 03:53 PM
What either baffles , amazes or riles me ( depending on the mood I'm in ) is why such a relatively simple challenge of keeping a cylindrical joint water -tight to 2 metres depth seems to be such a rarely achieved feature of binoculars.
In the industry I work in ( industrial and commercial heating and services ) there are many examples of situations where all manner of joints , flanges and instruments and various components MUST be water tight to far greater pressures than this , seemingly with no problem to the designer / engineer.
"O" ring technology is hardly rocket -science after all.
Just my thoughts -- Kenny.