Weems & Plath PRO 7×50 binoculars, customized for monocular vision

Several years ago I noticed that Weems & Plath had introduced a line of binoculars that seemed to offer good specifications and build quality at reasonable costs. But it took me until last fall’s Annapolis Show discount to take the plunge, and then it took some customization work to get where I hoped to. It’s an interesting story, I think, but to tell it I’ll have to reveal two more personal idiosyncracies.

First of all, and possibly not a surprise, I’m a bit cheap. And while being careful with my funds has generally served me well over the decades, I could kick myself for the series of “good enough” binoculars I owned before the Weem & Plath 7×50 PRO. I knew from using binoculars on other people’s boats that good quality can mean much better performance (and that Tim Bartlett had carefully explained why in PMY).

I also lack true binocular vision — as do many people, it turns out — so another attraction of the PRO model was independent focus adjustment. That meant I could fairly easily saw them in half and get two high-quality monoculars instead!

Weems & Plath Pro 7×50 binoculars become monoculars

Actually, removing the axel that aligns the Pro’s separate optics and permits a user to adjust them for their particular pupil-to-pupil width was a challenge. It takes an unusual spanner to properly unscrew the well-built retaining mechanism, but two thin machine bolts did the trick as illustrated above.

Then it was relatively easy to cut the now un-needed appendages off the Pro’s magnesium alloy bodies using a bandsaw. And, voilà, I had two monoculars that each weighed less than half the original Pro’s rather hefty 51 ounces.

After eight months of use, the Pro binocs/monocs have stood up well, with zero sign of internal fogging. That’s probably because they are tightly sealed and gas filled (and apparently my handiwork did no damage). They are also a pleasure to use every time I put one to my good eye.

In my experience, the 7×50 size really is the right balance for use on a boat, as explained in this Weems & Plath video. But 7x magnification with a 50mm objective lens are just two optical factors. For instance, the very similar W&P Classic binocs only have a 413-foot field of view at 1000 yards while the Pro’s 131m FoV at 1000m (seen above) translates to 430 feet. That may not seem like much, but it counts, as does the Pro’s increased ability to gather light. Note, for instance, what the Gizmo harbor view above looks like…

…when I pressed my cell phone camera to the Pro monocular eyepiece. There’s even some slightly dirty window glass in the way, but still I think the photo demonstrates the effectiveness of the Pro’s field of view, as well as pleasing and undistorted detail right out to the edges of the 7x magnifying optics.

A question I can’t answer with my vision is whether an easier-to-handle monocular is significantly less effective than binoculars of the same quality. But I’m struck by how many people do not have true binocular vision anyway, usually due to one weak eye. My favorite mate is also binocularly challenged, for instance, and so were two out of the six Woodenboat navigation students who were on Gizmo last week (and whose enthusiasm about my minocs inspired me to finally write this entry).

This Optometrist’s source says that “At least 12% of the population has some type of problem with binocular vision” and I understand that even people with a weak eye that’s now well corrected may not have learned core binocular skills in their early years. Is there a hidden market for marine monoculars?

Customizable Weems & Plath binoculars are available at many marine outlets and on Amazon, where I just noticed the Opticron Marine 3 7×50 Monocular. So you could have a monocular similar to mine without the customization work. But the Opticon’s specifications show the field of view as only 126m at 1000m (same as the W&P Classic’s 413 feet) and of course, there may be other subtle but visible differences.

So here’s a specific question for readers: If the good folks at Weems & Plath went to all the trouble of building a monocular to their Pro specifications, would you be interested?


Ben Ellison

Ben Ellison

Panbo editor, publisher & chief bottlewasher from 4/2005 until 8/2018, and now pleased to have Ben Stein as a very able publisher, webmaster, and editing colleague. Please don't regard him as an "expert"; he's getting quite old and thinks that "fadiddling fumble-putz" is a more accurate description.

6 Responses

  1. GM, Ben – a monocular is not of interest to me (us), as binoculars work well for me. I do note that over the years I’ve seen quite a number of people holding binoculars vertically, and using only one eye – it never occurred to me that there might be a medical reason! Our favorites are a pair of Canon 10X30 stabilized binocs that my dad gave me when we moved aboard in 2015 (he had them for many years for birdwatching) – the combination of 10X and the stabilization is a wonder to me – being able to read buoy numbers, boat names, restaurant names, etc. at a distance has been a real boon. We also have a pair of 7X50s for “night glass”, but we seldom use them.

  2. Ron Micjan says:

    Hey Ben, thanks for the article. I have not personally tried the BN50, but have looked through a wide variety of bino’s over the years. I have found that there are several levels of optics, the sub $100 stuff that is basically garbage, but good to have and allow guests to use aboard and occasionally drop. Then there is the $100-750 sets that are pretty decent and entry level for pro mariners. Most of your japanese binos are in here. At about $1k you start to get into the good stuff, Leupold gold ring, Swarovski, Steiner, Leica and that is the mid range, above $2k is where the really good stuff is. You owe it to yourself to look through a pair of $3000 Leica 8×42 outdoors where you can see the stunning difference that high precision ground optics make. We have 5 sets of binos aboard Zephyr, the captains set (leupold), the mates set (Leica) and 3 -$39 sets from amazon that the guests get to toss around. Then there is the NVG and thermal sets, but that is a different article. Smooth Sailing, Captain Ron

  3. Amy Wencel says:

    Thanks for the op-ed. I am one of those right-eyed navigation students who dreams of such a marine demi-binocular, with a bearing compass, or a binocular with a bearing compass I can see well with the OD. Not much of a gear shopper so maybe it’s already out there. And the leicas and zeisses make us swoon but it would be ideal to have a high quality piece with no extra glass, light enough to keep conveniently on one’s neck so we don’t have a little cry when it goes overboard.

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