Hans Seeger, Militaerische Fernglaeser und Fernrohre, 2.6, pages 185-200

Scissor Telescopes. Hans Seeger, Hamburg and Alfred Koenig, Herborn

[page 185] Observation from behind cover or protected from enemy

sight has always been a necessity in the military. The oldest device

for this purpose is the Polemoscope, a stand with two parallel pairs of

mirrors at 45 degrees to the tube. 'Hevelius maintains that he had

invented this Polemoscope in 1637' (Pisko 1869, where on page 51 is a

picture of such an instrument. See bibliography.)

In the `Stationary War' [Stellungskrieg] of the first World War, the

rampart mirror, known for centuries, was revived. We will mention the

simple monocular `ditch mirror', built with and without magnification,

only in passing. Hanns Guenther gives a very good synopsis of trench

periscopes in 'The War - Illustrated Chronicle of the War 1914/15', 3rd

volume (Stuttgart: Franckh'sche Verlagshandlung, 1915). Bombastically

and with the arrogance so common in wartime, it says, after having

talked about the primitive rampart mirror at the English front:

'The German technique, with a superiority that is shown in small

details, was not satisfied with a simple imitation of the rampart

mirror; but, using modern methods, created higher quality instruments,

including the trench periscope introduced by the Austro-Hungarian army

administration, which was constructed by the most important optical firm

in Austria: C.Reichert in Vienna.' [page 186] The pictures from this

work are shown in fig. 103.

At first we will describe a German made supplement to the telescope;

it adds to the field glass the functions of a periscope: namely

observation with a magnified view, from behind cover. Schwarte reports

in 1920, among other things, about this model: 'Half scissors for one

eyed use were frequently used; field glasses were also made usable for

trench observation by adding a set of mirrors to one objective, to raise

the point of view by 360mm.'

The unmistakable scissor telescopes, which in England are often

graphically called 'donkey's ears', are well-known and belong to these

military models. The advantages are obvious: One can observe from

behind cover, that is to say over a shelter, without being visible or

exposed to fire. Furthermore it is possible to observe from behind a

narrow obstacle (a tree for example), while standing up or lying down,

when the arms of the `scissor' are completely spread apart. [page 188]

In this observation position, because of the wide-spread objectives, an

especially `plastic' image is produced, with a degree of depth in the

image that allows one to distinguish the different distances of various

objects, which could not otherwise be observed. Fig. 105 demonstrates

the different uses of these glasses.

The development of the scissor telescope by Zeiss, Jena happened

simultaneously with the first manufacture of prism binoculars during

1893-94. Both of these forms of the prism binocular were protected by

the same patent (Patent no. 77086 of July 9, 1893). The first models

were smaller and known as `relief telescopes'. These have the

appearance of civilian instruments in their inscriptions, their looks

and their cases (see fig. 73). They could be bought on the open market

by non-military persons; but only with military usage did the advantages

of their design become fully clear. There are known examples of early

ten power `relief telescopes' with reticles, so they were produced for

military usage.

Pronouncements about whether the larger models of the early Zeiss

scissor telescopes were ever produced for civilian use or even intended

for it, would be pure speculation, and this question remains unanswered.

See fig. 73b and its text.

The predecessors of the scissor telescopes were at the time called

`relief telescopes'. They had magnification of 8 or 10 power, two

choices which proved themselves and were used again in the later

military models.

Note: In the Optical Museum of Jena, there is a 6 power relief

telescope; this version was probably produced in a small production run

until circa 1895.

In fig. 106 is the successor of the 10 power `relief telescope' (see

fig. 73a), which was named the 'Teleplast'* (*This name has caused much

confusion and mistaken associations between early Zeiss models. At

first the name `Teleplast' was used for civilian field glasses with

Sprenger prisms, see fig. 64 in 'Feldstecher'. These models have no

resemblance to the `mini-scissor telescopes',which were at first called

`relief telescopes'. The later 10 power small scissor telescope model,

from the first decade of the 20th century, was named the `Teleplast',

which, as mentioned, was used for another model as well). At first

glance, this model is recognizable as a military field glass. The

author knows of no eight power models in this design, that is, with gray

painted finish; and there probably was no corresponding Zeiss 6 power

model for military use.

Zeiss developed three larger scissor telescopes circa 1905, which

were exclusively for military use, and which are shown from the catalogs

in fig. 107. We can easily imagine that at Zeiss, the strategy was to

use the remaining time until 1908, before the patent expired, to be a

step ahead of the competitors, with several variations of their models.

The basis for all later, larger scissor telescope models, are these

three models: the Hypoplast, the army scissor telescope, and the scissor

telescope for field artillery

The specifications for these models were probably identical (10 x

40). The scissor telescope for field artillery is known to have

contained traditional Porro-I prisms which were cemented together, see

fig. 107, left. The other two models probably have the same prism,

indicated by the similar form of the prism housing. [page 190] This

design did not become obsolete, it is shown in figures 109 and 123. All

three models have a reticle which is not illuminated.

The scissor telescope for field artillery and the army scissor

telescope are similar to the earlier civilian (?) scissor telescope

model by Zeiss. Shown in fig. 73b is a Zeiss export model, and the

first scissor telescopes made in Jena must have been of the same

construction, or at least very similar. All of these models, as well as

the first relief telescopes, have the advantage of permitting

observation at two positions of the telescope arms: parallel and

upright, or out spread. The directions for the scissor telescope for

field artillery explain the advantages:

'Preliminary remark: in one position for use of the S.-F. for field

artillery...the observer views from behind an obstacle (for example, a

trench); and in the other position...around an obstacle (for example, a

tree); consequently he is protected, in either case. The S.-F. for

field artillery, when used with out-spread arms, provides a much higher

plasticity of the image, and the objects consequently appear behind each

other, not next to each other, and strongly distinct from the

background, (corresponding to their natural position) even at large

distances.

The use of the S.-F. for field artillery will consequently be most

frequent with out-spread arms.'

But at the front lines of W.W. I, the reality was different, see

also the remarks for S.F. 17.

[page 191] The Hypoplast purposely abandoned the advantages of

maximum enhanced depth of the image. The Hypoplast has only one `work-

position' of the arms, which can be seen in figures 107 and 108. The

Hypoplast uses a configuration that is in between the two characteristic

positions of a traditional scissor telescope, the first position for

observation from behind cover, and the second for an enhanced depth to

the image (which results from the larger `basis' or wider distance

separating the objectives compared to the interpupillary distance (see

`Feldstecher', page 131). For the Hypoplast, this distance is not as

large as for a scissor telescope with fully outspread arms, and its name

indicates this as well: Hypo means lesser or diminished.

In 1911 the old Hypoplast was revived in a new form as 'Hypoplast

1911', with a 10 x 50 configuration. There is only one working position

of the arms, similar to the original Hypoplast, see fig. 108. No

survivor can be shown for this model, and it probably was built in very

small quantities. This note from a Zeiss magazine probably was not

confirmed by reality: [page 192] 'It is superior to the scissor

telescope by its greater simplicity of use. This is achieved by the

fact that the telescope arms have a fixed position to each other, which

results in the observer remaining behind cover, and in addition provides

images with higher plasticity. By the simple turning of a screw, the

interpupillary distance of the observer is adjusted to; while all other

scissor telescopes require several manipulations. This version is

protected by a Zeiss patent. In the right ocular there is a reticle,

which is made with any desired partition.'

The optical construction of an early scissor telescope is visible in

fig. 109. It can be seen that both prism configurations are derived

from the Porro I and Porro II systems. The prisms in American scissor

telescopes, which in the U.S.A are called battery commander's

telescopes, are described by Jacobs (1943, page 219), and shown in fig.

109.

Some scissor telescopes use roof prisms, as do some hand held

telescopes. Fig. 109 shows the prism of an S.F. 14 in its mounting.

The leading optical firms in Germany produced scissor telescopes

during W.W. I, and probably were already making them in the years before

1914. The starting signal for most of the firms would have been the

expiration of the Zeiss patent in 1908. In 1893, Zeiss patented the

prism binocular with increased distance between objectives, and also

protected the design of the scissor telescope in monocular and binocular

forms.

As with some military glasses, some scissor telescopes signed by a

company were of different manufacture. We shall not dwell on the small

differences betweem scissor telescopes with the same name, but by

different producers.

A model that is not rare even today, is the S.F. 09 (S.F. =

Scherenfernrohr [scissor telescope]). From the number 09, it can be

deduced that this widely used standard model was introduced in 1909 for

the use of the German military. Fig. 110 shows this 10 x 45 model with

bearing circle. In fig. 115, the typical reticle for the S.F. 09 is

shown, which was not yet illuminated. (Nearly all later S.F.s with

reticle have illumination for the reticle). In fig. 110, the

transportation containers for the cavalry can be seen.

[page 193] The S.F. 09 has excellent optics, and it is therefore

not surprising that this model, along with other optics of W.W.I, was

still used by the military during W.W.II. An interesting example of

this is shown in fig. 110. This S.F. 09 was officially rebuilt and re-

engraved, and the grey blue color of W.W.I was painted over with the RAL

regulation Army grey-green. Also, the engraved artillery symbol (the

grenade symbol, a cannon ball with flame), was painted over. The S.F.

received different oculars, a [Gitterplatte, type of reticle with a

grid], and a built-in illumination window for the reticle. The new

engraving: 'Gi H/6400' (=Gitterplatte) indicates this reticle.

Shortly before and during W.W. I, other scissor telescopes were

built. In 1914, before the war, the S.F. 14 was built by Zeiss for the

foot artillery. Its specifications, 10 power and 50 mm objective, were

kept for most of the later models until the end of W.W. II, but the

short design was not retained. The distance from the middle of the

ocular to the middle of the objective is only 220 mm. in the S.F. 14 for

foot artillery. The advantages of this short construction are less

weight and a handier form, but these do not make up for the disadvantage

of an insufficient capacity for the observer to maintain cover. Fig.

112 shows an example of this rather rare model.

[page 194] Because of the disadvantages of the foot artillery model,

shortly after the start of the war (1914), the S.F. 14 with elongated

arms was introduced in Jena. It resembles its predecessor in the

markings and optical specifications, but the arms are elongated by

110mm.

Goerz, Berlin, also developed an S.F., which distinguished itself

from the Zeiss models by a characteristic form. The specifications were

also 10 x 50, see fig. 113. Fig 115 shows the reticle of this S.F.

Another producer of this variety of S.F. is the company A.-G. Hahn,

Cassel.

In the course of the first world war, from about 1916 on, a larger

version of the Goerz S.F. was built, the 'M 16' (M= model?), see fig.

113. The M 16 was produced in low numbers, with specifications of 15 x

60. In Jena, Zeiss made a 15 x 60 S.F., produced in a small production

run (f.o.v. 58m/1000m).

Zeiss modified its own S.F. 14 (with elongated arms) during the

first World War. Using the same optics, the telescope bearing and the

height device were changed, and thus the Zeiss S.F. 14 Z was born, which

in nearly unchanged form was made until the end of the second World War

by the leading German optical firms.

Even in the modern German military, this model was used; because

S.F. 14 Z Gi examples, with the color of paint used by the Bundeswehr,

and with coated optics are known. [page 195] It is not clear, when and

how these S.F., which were the property of the Wehrmacht, entered the

Bundeswehr, and where they were overhauled. In the beginning of the

Bundeswehr, it probably wasn't S.F.14 Zs that were used, but rather the

American BC65 (see fig. 123). But this battery commander's telescope did

not meet the expectations of the German military. Many of them were

modified by Zeiss in Oberkochen, so that they fulfilled minimum optical

requirements. Understandably, this procedure was not publicized (from

the communication of a Zeiss colleague).

A slightly modified S.F. 14 Z Gi was built in the second World War

for use in tanks. It had a small, removable forehead support and did

not have a spirit level for measuring the angle of the terrain. In the

interior of the tank, there were movable arms with pegs to install the

scissor telescope (we will not describe the successor to this

instrument, the RWDF 10 x 50 developed by Zeiss Oberkochen in 1956/58

and delivered after about 1960.)

With a relatively small field of view, (87 m/1000m), an S.F. 14 Z

delivered a precise and sharp image. One can recognize details and is

given the impression of looking through a higher power telescope. This

excellent optical quality explains their frequent use, especially during

the second World War. Therefore the following official communication

from the war years is astonishing, and possibly the high command of the

Army may have been afraid that the German soldiers had not made

sufficient use of their optics at night during the war.

General Army Communication of June 7, 1941:

'Use of binoculars and scissor telescopes at night. It is to be

noted that at night, the distance of effective observation of the

unaided eye can be doubled with the 6x30 binocular, and about tripled

with a 10 x 50 binocular or a scissor telescope O.K.H. (Ch H Ruest u.

BdE), May 31, 1941. 79 ln4 (IIIb)'

A major problem for the S.F. 14, as for all scissor telescopes, was

that of collimation: the length of the arms and the fact that they are

freely movable (as the long arms of a lever), permits an exertion of

very little force to slightly tilt the arms and therefore move the

optical axes from parallel to each other. Because of the relatively

high magnification, a fused image, (with no double image), can only be

seen after a precise collimation. The rough treatment which a scissor

telescope has to endure during its `life' means that a perfectly

adjusted specimen is rather rare. Those which are aligned in both

positions of use, (with upright arms and with outstretched arms), are

indeed rarities. (The alignment of an S.F. is an unloved and thankless

task even for the experts.)

The S.F.s of the first World War, along with those of the Imperial

Army, and those which were built at the beginning of the second World

War, made use of brass and show careful workmanship. Specimens from

circa 1944 are `simpler', but retain the same optical quality.

All military S.Fs were painted, and during W.W. I, field grey was

the only color used. In the mid-twenties, new instruments for the

Reichswehr were delivered with a camouflage paint (official name:

multicolor paint); but this was not extended to all older instruments.

In the Army instruction pamphlet of the Reichs ministry of March 1927 it

says:

'Painting of the scissor telescopes: A replacement by the troops of

the field grey paint with the multicolor paint on the existing scissor

telescopes is not intended. The multicolor paint is only intended for

the scissor telescopes from the new production.... S.F. 14 Z on hand

will keep the field-grey paint.'

A short time later, the perceived need for camouflage paint on the

existing supplies must have become greater, and the `nit picking'

attitude was officially abandoned. It says in the Army instruction

paper of August 1928 under 'paint for observation and measuring

instruments': 'The troops can acquire the special paints for the

observation and measuring instrument on the open market.' Obviously the

troops were able to individualize `their' instruments from that point.

Today we find old German scissor telescopes in grey, grey-green, olive

green and so on. In addition to the Reichswehr, the Wehrmacht must have

used the tricolor camouflage paint. During the second World War, blue-

grey, green-grey, sand, and clay colored paints were frequently used.

The S.F.s that were produced at the end of the war were without the red

primer undercoat.

An important part of an S.F. is the reticle, which was mainly needed

for target shooting at sight, for artillery measurements, and for

estimating distance. The reticle is placed in the image plane of the

ocular, so that the scale and the observed image could be seen at the

same time, similar to the cross hairs of a rifle scope.

During the first World War, there was a diversity of reticles; but

the later reticles, of the Reichswehr and Wehrmacht, were mostly

standardized. During this time, a new reticle was developed: the

Gitterplatte [grid plate], initially used for special purposes. The

authors cannot give an exact date for the introduction of this. [page

197] In the paper by Kaiser (1918), the 'well known grid-plate' is

mentioned, and therefore some S.F.s were equipped with the grid plate

during the first World War. The S.F.s with `existing' reticles were

known as 'SF 14 Z', and the S.F.s with grid plates were named 'SF 14 Z

Gi'. From the outside, the two models are indistinguishable. The grid

plate, see fig. 115, was of such great benefit that during the second

World War, it was used almost exclusively. The grid plate was the

characteristic mark of the German S.F. of the second World War. From

the Army instruction paper of January 1937, it can be seen (in the most

beautiful language of officials), that the grid plate was generally

built into new instruments only after this point in time.

'Scissor Telescopes 14 Z with Grid plate. Scissor Telescopes 14 Z

with grid plate can only be issued according to the availability of the

new aquisitions.

An exchange of the S.F. 14 Z without grid plate for those with grid

plate therefore cannot be made at the present time. High Command of the

Army, January 19, 1937, AHA/Fz (V).'

A reticle or grid plate alone is not sufficient to fulfill all

requirements for use of an S.F. under front line conditions. To correct

the angle of the artillery fire, the advance observer has to use his

S.F. to transmit the position of the exploding shells in the form of

angles of azimuth and altitude. To establish the angle of altitude,

there is a so called `terrain angle measuring device' mounted on the

S.F.

To measure in the horizontal direction, there is a measuring dial,

which is an accessory placed between the tripod and the S.F. During

W.W. I, flat measuring dials were used, but the Reichswehr and Wehrmacht

only used high (drumlike) measuring dials, see fig. 116.

The accessories for the S.F. also went through certain changes in

the course of time. Tripods made of wood or metal, in small or large

sizes, were used to mount the S.F. Alternatively, large screws were

used, to fasten the S.F. on a board, tree trunk or tree.

To protect from rain and to avoid stray light, rain protectors were

mounted on the objectives. These are pipes that are 60 to 250 mm in

length. For observing with bright light in one's eyes, filters with

different yellow tints can be put on the oculars, as with other military

fieldglasses.

In the dark, the reticle of the S.F. could be lit through a small

glass window by means of a little lamp. The attachment for the lamp is

on the tube of right ocular. All markings of the reticle are etched in

the glass, for superficially applied marks on the glass would not be

visible in the dark when lit from the side. The power source was an

accumulator or more frequently, dry batteries, which were stored in

leather or tin battery containers.

To clean the S.F. in the field, there was a hair brush and a dustrag

as accessories.

The S.F. and its accessories were stored in containers of leather

(cavalry), plywood or tin (motorized troops); and for the tripod there

was another container.

Another accessory for S.F. increased to 20 power the standard

magnification of 10 power. By mounting the optic shown in fig. 116 in

front of one objective, the magnification changed by this factor. This

attachment is only mounted on one side of the S.F. Were one mounted in

front of each objective, a fused image would be difficult to achieve.

(Double images are already a problem at the slightest deviation between

the optical axes of the right and left sides.) The optics shown here

come from the former NVA (East Germany), and to judge from the olive

green color, from the troops of the Warsaw Pact. It can be deduced from

the special holding clamp (see fig. 116) that this optic is from the the

Polish scissor telescope 'AST, Military Designation'; because the

attachments for the AST includes such an accessory (Terry Vacani,

personal communication). The authors have been told that such optics

were used by the Wehrmacht, but there are no known specimens to proove

this. John Gould, who was assigned as an inspector of captured optics

after W.W. II, does know of similar German S.F. accessory optics. Only

German military optics were examined in this British bureau. The optics

shown in fig. 116 are therefore probably the post war successors of a

German accessory.

Changing the magnification of a S.F. was effectively achieved in the

last century. However, another and more obvious method was chosen at

that time, rather than the above discussed solution by means of an

attachment. The early S.F. models in question had an ocular revolver

[turret]. This device for changing magnification was integral to the

S.F., and therefore more elegant but also much more expensive. [page

200] With these S.F. models, binocular viewing using increased

magnification on both sides is possible. The first S.F built in this

form was a modification of the scissor telescope sold in military and

also civilian forms after 1899. The model with the ocular revolver had

the markings: 10 + 18 x 30, and an arm length of about 26 cm.; by

turning the revolver the magnification could be changed.

The ocular revolver was also used in the Marineglass, fig. 192, and

in another Zeiss field glass. It was soon adopted for a larger military

S.F., and there is one of these interesting Zeiss S.F. models from the

time before the first World War, shown in fig. 117. The author does not

know of any other examples of this glass. Though the objectives have a

diameter of 50 mm., this model is probably the AP 9082 A, used in Great

Britain, which is described as a 10 + 20 x 42. (William Reid, personal

communication). This British Admirality Pattern Number is puzzling for

an instrument that was never used on board a ship, and there is an

astonishing explanation: 'In W.W. I, tanks were His Majesty's land

ships, and were the responsibility of the Navy' (John Gould, personal

communication). This S.F. was surely an ideal instrument to use as a

tank weapon. The depicted AP 9082 A was still used long after W.W. I,

and the second proof number, from the NPL (National Physical Laboratory)

of 1928, confirms that fact. The models still existing in Great Britain

were only declared `obsolescent' in 1943. An object declared

`obsolescent' in Great Britain could still be used for some 10 to 15

years; and only after it was declared `obsolete' was the object taken

out of circulation. (John Gould, personal communication).

An unusual rangefinder in the form of an S.F. is shown in fig. 118.

This model, developed in Germany during W.W. II, served to measure

distance, and to observe at the same time. It is less prone to

misalignment, and can be used from behind cover. Between the two

objectives, there is a `waagerechter Kollimationsstrahl' [balanced

refracting collimation device]. This stereoscopic rangefinder was

produced by Zeiss (blc) and Busch(cxn) until the end of the War. For

details about this 'Disvau' (Zeiss) 'rangefinder of rugged

construction', see Koenig/Koehler 1959, page 411. After the war,

production under the name Em 61 [rangefinder 61] was continued in the

area later known as the Eastern block. It is not clear if only Zeiss

Jena produced them, or if they were also made at different places.

Later models, similar but of larger and smaller construction, were

added. These instruments are modified from the wartime models, for

example some were supplied with light amplification, see fig. 119.

In the Wehrmacht there was also an instrument with a 1.25 meter

base, a 40 cm. instrument for the NVA-Pioniere, and for the post war

Soviet Army a model with a 2 meter basis and detachable arms. Older

Soviet scissor telescopes are known, whose optics have stereoscopic

measuring marks. Obviously they were used in stretched out form, as

stereoscopic rangefinders, but from the outside they are hardly

distinguishable from the usual S.F. (Heinz Radimersky, personal

communication).

8

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