Binoculars Prismatic No.2 Mk.2 - Advice

[Flying10uk]

I think from memory these were ship built guns housed along that stretch of the battery wall.

That would explain why the gun is mounted in a turret.

[bigduke6]

As Gil said, The Guns are Navy ones (150mm) not all the guns were German though, a lot of captured French ones were used the Longues-Sur-Mur were Skoda made ones.
Great place to visit, I found out where Longues-Sur-Mur sister's command post is, although the author of the book states a name he doesn't disclose the exact place, so a bit of google satellite of the area and I've nailed it, quite a trek from where I was so thats on the cards for next time, For anyone going I would avoid the days before and after D-Day, if there only transport is car, I'll say more when I do a post later, lot of pictures to upload etc.

[Micheal Doyne]

So they have arrived, and to be honest I am really rather happy with them. However in an ideal world they could be a little clearer, there appears to a some internal dust. But other wise they would appear to be the best binoculars I have to date owned for lack of eye strain and double vision.
I appreciate from Peter’s comments on another threat that these are not simple to service, and if one where too finding some one experienced is imperative. So would any one know a uk based person who is still servicing these?

[Charlie303]

They look like very nice binos, especially at £29.99!

Bound to be a bit of crud on the optics after all this time, but they look better than 99% of the ones I've seen at shows, and generally going for more than £29.99.

The few black flakes probably a result of the internal black coating breaking down a bit, but nothing much to worry about. Taking them apart to clean them would do more harm than good, unless you can find a real expert. And what might that cost?

[bigduke6]

Mike, I've had quite a few apart but as for servicing only ever cleaned them and replaced lens etc, Charlies correct on the inside paint breaking down, you can go chasing your own tail trying to sort this at time, as in Peters post the smallest bit of dust can look like something a lot bigger.

[Flying10uk]

I once purchased a pair of bins on eBay that were supposed to be "good" and one side had a thick yellow pee-souper of a mist and the "best side", you could almost make sense of the image that greeted you when you looked through the eyepiece. The vendor was ok about and we resolved the matter between us. Apparently the vendor had forgotten to "check" the optics before listing them.

[Gil Boyd]

Yeh right!!!

[Micheal Doyne]

So, I now apparently own 6 pairs of No.2 Binoculars ranging mk.1-3. So as they all need work, I’m giving serious thought to having a go my self. Does any one know where I might be able to acquire some drawing or more ideally some maintenance manuals?

[Peter Laidler]

My advice would verge between tread VERY carefully and don't bother yourself. You will be dealing with sintered cheap aluminium alloy, part threaded radiuses, left hand threads 10BA x 3/32" long grub screws dissimilar materials with (slight) corrosion between the two. If you really do want to have a go, just get a really cheap dirty pair and where you do come across a problem - like one locking grubscrew on top of another - a good little trick played on the unsuspecting - or a thread that's crumbled away then you can learn from it. Likewise, if you have to force a prism out of its housing........ That's just the body of the binos. Then there's the two eye pieces made up of a series of ocular, first and field lenses AND a plate.

And then stripping one side down again after you've assembled them because the ocular assemblies have magnified a fingerprint you left behind on a prism. Never ever touch the prisms with your bare fingers. Always neoprene gloves and economy paper kitchen towel that doesn't contain chemical additives.

Never but never ever mix up prisms or lenses between sides nor mix up a front to rear prism or a prism side to side. Always mark the side of the prism with F-R-I for Front, Right side I= inside facing or whatever markings you choose to invent. Or if some other instrument Tech has been there first and put his marking on the prism's or lens edges, then WRITE then down to indicate the exact position

[Micheal Doyne]

Hi Peter,

As ever thanks for the advice, they sound a fiendish instrument to service. Is the a written record of the methods for servicing these, or where they junked once damaged? I have two pairs of optically dubious quality that cost sub £8, when I have set me self up I will give them a look before attempting any sort of work on my more functional sets.