In all sorts of warfare observation and target aiming is very important: find and pinpoint the enemy as soon as possible. Optical devices had in most cases a multi-role function. With a periscope one could observe the environment in general. But with the built-in reticule is was also possible to calculate a rough distance. Some hand held binoculars had the same feature. During the night the cross hairs were lighted by a small lamp, which was powered by batteries. For extra precise measurement, aiming circles were used. Tripods provided the needed stability.

In fortification structures (Atlantikwall and others) a variety of fixed binoculars, periscopes and range finders were used. Protecting the weaponry by placing it in armoured cupolas or behind steel plates, also meant a lack of information in what was happening outside.

On this site we will try to give you a glimpse of the inventory of optics that were specially made for fortification use. This means most of the optics dealt with are very specialised, in most cases easily identifiable examples of mid-twentieth century craftsmanship. Most of these are monoculars. ‘Bunker’-binoculars exist as well. Note that ‘Bunkeroptik’ is our own invention and not an official German term. We make a division in army optics (Heer), which as mentioned above were integrated in the armoured parts (turrets and plates) in bunkers, and naval (Kriegsmarine) optics of which most came directly from war ships.

Kriegsmarine optics

It must be noted that the largest German fortification effort, the Atlantikwall, began taking shape in 1942. Materials and other resources got even more scarce day by day. At the same time the Kriegsmarine surface fleet expansion plan (the Z-plan) was scrapped. Higly specialised KM-optics already built for the surface fleet to be, became available. These were transferred to land-based coastal defense Kriegsmarine units only to end up (after minor adjustments) under a concrete roof overlooking the European beaches. This is only one way in which our nowadays “common” Kriegsmarine binoculars found their way into fortification use. No other arm of the German armed forces had such an elaborated cooperation with the German optical industry as the Kriegsmarine. To spot before being spot by the enemy was crucial in navy warfare, especially in times when radar wasn’t available yet. The partnership brought the Marineküstenartillerie (German naval coastal units) in the position to have special binoculars created for their own needs. This in spite of the scarce resources and the fact that models for non-Kriegsmarine for the same purposes were available. An excellent example is the “KM” 10 x 80 80°: a specific Kriegsmarine-made binocular which wasn’t designed for classic “naval” use and never saw service on a ship.

Navigation on this site

There are several sections in the Bunkeroptik part of the website.

Bunker optics

In the optics section you can find all army bunker related optics divided into the purposes: observation and aiming.

Go to bunker optics section


The first optics help for the individual soldier. Binoculars were made by the thousands and in many different variations for different purposes and army organisations.

Go to binoculars section

Scheren- and Doppelfernrohr

Observation for all different purposes but not hand-held. For (coastal) artillery, Flak, and general observation on a larger distance.

Go to observation section

Aiming sights

These include the big Kriegsmarine sights for aiming coastal artillery and small MG-sights for the regular army.

Go to aiming sights section

Survey sights

Construction workers need very acurate instruments, for instance for placing the foundation plates of gunbunkers and firecontrol stands in the correct position.

Go to surveying section


Besides a magnified eyeview you also need geografical information for orientation and targetfinding. Compasses give you the magnetic north pole, so that you can determine a direction. There are also optical instruments that combine magnification with a compass. The pictures show Lenco’s former collection of compasses and more.

Go to compasses section

Research section

German equipment was often marked with several sorts of manufacturing (ordnance) codes. There are a few books and internetsites on this subject. We made a first start with the available information. The list will grow in time and your questions are welcome. The technical markings found on the optics are also part of this section. Furthermore we will try to explain how some simple lines in the glasses can tell the distance to the target and we bring some background information on German optics manufacturers.

Go to research section

Repair shop

The late Lenco van der Weel (1950-2022), who started the Bunkeroptik part on the website and inspired me to collect these pieces as well, specialised in cleaning and fixing hazy and faulty pieces of optics. His restoration projects including how-to’s and pictures are shared for you to learn from. Unfortunately this section will not be updated anymore.

Go to repair shop

Links & sources

Links to other interesting optics websites and references to books used.

Go to Links & sources


The authors of this site have no connection with any commercial or political organisations. We do not advertise or sell any equipment through this website, nor do we take restoration requests.

The copyright of the pictures and provided information rest with the authors, unless stated otherwise. As the pictures on Ebay and other internet auctions are part of advertisement and thus in the public domain, we will use them. If someone claims to have rights on any of the other pictures on this site, please send a mail.