The Weems & Plath 7X50 Navy One binoculars are standout performers among marine binoculars. But, how often have you heard the name Weems & Plath come up in connection with optics? But if you get a chance to look through a pair of these, I expect you to be impressed. They put up a bright and sharp image from a rugged set of binoculars in a waterproof housing. They are just about ideal as general purpose low-light binoculars, but the brand just isn't known. If you're a contrarian, here is self-vindication incarnate.

Background

I am not sure I ever would have heard of Weems and Plath or their Navy One binocualars if I hadn't run into a set of these at a boat store in New Orleans. I wasn't actually looking for binoculars at the time, and picked up a display set of out of idle curiosity. And, that was where I was frankly surprised- compared to the Steiners, Swarovskis, Zeiss, and Pentax units they had, they did just as well, and ususally better. The Bushnells and some Swifts were left on the side of the road.

These are marine binoculars labeled as "Night Glasses" because at a prescription of 7X50, they do more light amplification than magnification compared to most conventional binoculars. The difference this makes is at twilight and later, they perform as passive light amplification devices which provide an image about 7.3 times brighter than the unaided eye would see. In comparison, a common hunting binocular claimed to be useful for twilight with a prescription of 8X42 will only have a light amplification of 5.1 times what the unaided eye would see.

In practice this means the binoculars will produce an extremely bright and sharp edged image in all lighting conditions. The down side is this optical prescription has more of the severely curved outer diameter of the lens in the image, so false color is a bigger problem. If you look at my notes on choosing a telescope, there is more detail on exactly what is going on in short focal length refracting telescopes (which binoculars are just a pair of).

Description and Observations

The NavyOne binoculars finally got ordered this year after it became clear Arizona has too many far vistas to miss, and too many night skies worth browsing. I bought them online for $205.50 from WeatherPatrol (www.weatherpatrol.com). They showed up three days later in a very well packaged container. The binoculars simply came in a box with an instruction book, a bright yellow neoprene neck strap labeled "Weems and Plath", a narrow low profile neck strap, and a cleaning cloth.

Weems and Plath says they are designed to meet US Navy specifications, but I have no idea if these binoculars are, in fact, being used by and part of the US military (if someone out there knows for certain, I'd be interested in hearing the answer).

The binoculars are very ruggedly built with full rubber armor, waterproof housings, dry nitrogen purged interior, and individually focused eyepieces with large flat-edged eye cups around the eyepieces. The overall color is perhaps a little more charcoal gray than black, and the NavyOne logo inset is subdued (I actually think this is a neat touch).

There are two very significant features of these binoculars which are not included in the online documentation: First, unlike a set of Zeiss Ultra-Rugged binoculars, the individual focus on these does not need to be continuously adjusted. On the NavyOne you focus the eyepieces on an intermediate distance object and then they behave like a set of the "Focus free" binoculars from about 30' to infinity (I have never gotten the focus free ones to work very well before now, so I am a fan of this feature). Second, the front of the hinge between the two oculars has a screw-off cap which reveals a standard 1/4"-20 tripod thread to mount to a camera tripod with any standard binocular adapter (you can find these at places like Orion, www.telescope.com). This is useful for any time you want to keep watching one scene such as wildlife or astronomy without having to hold the binoculars up.

The lens caps are all designed to be captive. The front end ones are attached to the rubber armor, and just hang at the front when open. The eyepiece lens cap needs to be threaded on to the neck strap to be captive, but it easily fits on either neck strap. At the weight of these, I do not see how the thin strap would be usful unless your primary use was with them mounted to a tripod, so all you needed the strap for was to mount the eyepiece cap and as a hand carry handle.

Like most binoculars, these are hinged in the middle to adjust the distance between the oculars. The one piece eyepiece cap seems to assume the oculars are closer together in their more compact orientation. In my own case, I need to move the barrels closer to get the eyepiece cap on. The focus does not appear to shift significantly as the caps go on and off.

Usage

I was really looking forward to these for night time use, but they also are very functional in daylight. In general, since the images are bright, objects have a sort of "Realer than real" appearance with extremely vivid and sharp contours and high contrast. So, for example, when looking at a woodpecker on a telephone pole 40 yards away, there is a very strong 3D effect and very strong contrast on features. With lower contrast scenes, such as looking at mountains 50 miles away with atmospheric haze in between, the image is clearly sharper than what the unaided eye sees. There is some downside since the image on a bright summer day can be bright indeed, so some cases you may want to use sunglasses.

The lens system has a lot of curvature, and it does have some false color as a result. For example, if you look at a black and white object, such as a speed limit sign, there will be some violet halos around the strongest contrast. This isn't very strong if your eyes are at the center of the pupils (if this were the case, I would have rated these lower), but if you do not have the oculars set to the right width or your eyes are not at the center of the eyepieces, then the false color becomes much stronger. This is one reason binoculars such as 10X50 or 8X42 are more common- that last bit of aperture comes with a lot of engineering difficulty. The poroprism image rectifying design may be physically larger than the roof prism used in many Zeiss and Swarovski binoculars, but it does improve stereo image perception and most importantly does not produce glare in low light they way a roof prism does.

All in all, there is no practical false color in daytime images on common objects such as terrain, wildlife, trees, people, and so on. For night time use, I was unable to find false color in these optics.

At dusk and later, the high brightness optics make scenes and objects visible when they are otherwise lost into shadows. This is one of the more interesting uses since it is specifically what these binoculars were designed for. So, for example, if you look at an aircraft flying at night, the lighting on the ground will be bright enough to make the fuselage and wings visible, where otherwise only the navigation lights can be seen.

Pointing the binoculars at the night sky is another treat again- the night sky suddenly is full of stars. The 7.1 degree field is very large in astronomical terms since it corresponds to 14 times the diameter of the full moon. This makes a lot of extended objects such as the Beehive star cluster and the Lagoon nebula visible as objects in a field. In my own case, several star clusters jumped out which are so large in the sky, they simply do not show up in telescopes with their smaller fields of view (where 2 degrees across is a large field of view).

One thing I quickly noticed in the city is when I took the binoculars down from my eyes, the circular field from the binoculars showed up as a dim area in my night vision. The night sky glow from the city ligts was greatly amplified in the binoculars so that portion of my vision had light adapted. Of course, out away from city lights, this isn't such a large problem since if your eyes are light adapting there, it means there is plenty of light in the image to see clearly.

The binoculars fit well in the hands with their knurled outside texture. The focus once and forget it feature also means they are usable while wearing gloves. However, I find holding them up for extended periods does get to be tiring, so I strongly recommend thinking about getting a tripod adapter.

Recently, I have been forced to start wearing glasses thanks to astigmatism (argh!), so I have started learning about using binoculars and such while wearing glasses. The eyepiece cups don't really fold down so much as they roll down. In practice, this puts the top of each eyepiece cup over the knurling on the eyepieces. If you don't get the eyepiece cup all the way down, it will pop back up by itself in about a minute. The binoculars are actually usable with the cups up, but depending on the eyewear you have, this may put the eyepiece so far away that the outer part of the image is cut off. In my case, the sharpest images are not available unless my astigmatism is corrected, so I have been rolling down the eyepiece cups.

Conclusion

The NavyOne 7X50 are a great value for the money. The high brightness optics are well executed and produce very bright and sharp images. The binoculars come completely ready to head out into rugged environments on or off land. The individual focus once and forget it mechanism works extremely well, and easily makes these binoculars very useful for quickly reacting to look at an unexpected sight. Their low light performance is superb, both on the ground and on the sky, and the built in attachment point for a tripod adapter means they can be used for long observing sessions hands free. Given my only complaint is how the eyepiece cups tend to pop back up, these are very satisfactory indeed.

Recommended: Yes