The Scherenfernorhrs (SF) - Part II Technical Description and Operation

According to "Der Artillerist, (1) Der Kanonier (1940) the SF was to be used for:
1) Observation and reconnaisance
2) Measuring angles of azimuth
3) Measuring angles of site and elevation
4) Measuring height of shell bursts
5) Establishing safety zones for advancing friendly troops
6) and to lay field guns.
The piece was often seen in different variations of employment in vehicles and on the ground proper, through the use of the tripod leg assembly, and the periscope assembly had a magnification of approximately 10X. It normally came with accessories such as the azimuth mount, tripod, carrying case, and other items such as a battery powered removeable illumination lamp kit and a "trench mount" which was approximate to a sort of screw that could allow the unit to be imbedded in wood or the ground.







The SF's optic tubes can be positioned vertically, or it may be swung horizontally to increase the stereoscopic effect. The reticle (explained below) stays upright regardless of what position one places the tubes.



Operation

1) Clamp tripod legs at desired length and embed firmly in ground, tighten leg clamps. Using spring plunger, clamp telescope on the vertical spindle coming up from the orienting mount. Level the mount by centering the bubble in the circular level. When the bubble is centered, clamp down the ball and socket joint on the lower mount.



2) Prepare SF. Release telescope clamping knob, and turn the telescope elbows to the verticle or horizontal position, as required. Set proper interpupillary distance on the interpupillary scale, graduated from 55 to 75mm, and clamp the interpupillary wing knob. If the i-p distance is not known, look through the eyepieces at the sky and move the eyepieces together or apart, until the field of view changes from two circles, or two overlapping circles, to one sharply defined circle. Then, clamp i-p wing knob. Next, focus each eyepiece independantly by covering one and looking at an object several hundred yards away - turn the diopter scale until the observed object appears sharply defined. The diopter scale on each eyepiece can be adjusted for known optometric prescription, if necessary. You can also place the supplied light or dark filters over the eyepieces, or attach sun shades to the outside, or as well as the extended tubular sections, about 8 inches long, that are attached to the sun shades to protect against rain.



3) Orient the SF. Select a datum point of known azimuth, and set this value of the azimuth scale (100-mil steps) and micrometer (1-mil steps). The throwout lever may be used for making large changes in azimuth rapidly. Turn the telescope with the orienting knob until the datum point appears at the center of the reticle of the right-hand telescope. The orienting clamping knob may be temporarily released for making large angular changes rapidly. Afterwards, only use the azimuth knob, or for large changes, the azimuth throwout lever, and the correct azimuth of the point observed will be indicated. For azimuths in the 3,200- to 6,400-mil region, additional numbers (0 to 3,200 mils) are provided, which correspond to the azimuth scale on the RblF (panoramic) telescope, which is covered in a separate entry.

4) Aim the SF. Direct the telescope on the object, then rotate the elevating knob until the object appears at the center of the reticle. Center the angle of site bubble by adjusting the angle of site knob. The angle of site is then read on the angle of site scale, which is graduated in mils. An indication of 300 corresponds to a horizontal line of sight.

5) Reticle. The most commonly recognized reticle, always located in the right eyepiece, is a grid, the horizontal and vertical axis of which are graduated in 10-mil intervals. However, various other types of reticle have been encountered in SFs. These reticles styles date back even to First World War Models. Hans Seeger documented other reticles seen as below (Note: not all are SF's check the legend):


From: Seeger, Hans, "Militarische Fernglaser und Fernrohre in Heer, Luftwaffe und Marine"


#1 - S.F. 14 manufactured by Zeiss for Foot Infantry (First World War).
#2 - S.F. 09 manufactured by C.P.Goerz (Berlin)numbered 8477. Similar pattern repeated on later Em-type rangefinders for vehicles.
#3 - S.F. for Foot Artillery (First World War). This particular reticle pattern came from a S.F. model numbered 2571 and serial numbered 393403
#4 - S.F. This same reticle pattern is also found in the following optics: 6 x 30 Dienstglas marked ddx - model Nr. 263253, 6 x 30 Dienstglas marked cag - model Nr. 123470, 10 x 50 Dienstglas marked rln - model Nr. 29258. Typically found in all similar optics with a marking of "H/6400"
#5 - The grid pattern (or "Gitterplatte") for a S.F. 14Z Gi. From the Heeresdruckvorschriften 448/1 of July 1940.
#6 - Rm F 12 x 60 for Em 4 m R 40 rangefinder device, marked blc, model Nr. 272289
#7 - 7 x 50 and 8 x 56 made by Leitz. From the Heersdruckvorschriften 448/1 of July 1940.
#8 - Beobachtenfernrohr ("observation glass") 12 x 60 for 4 m R (H) 36, model Nr. 221193.

Additionally, the SFs that were specifically delivered as standard equipment in tanks had either the grid-style or an "L-shaped" similar to Seeger's diagram and shown in one of the examples below. All SF's that had a reticle grid were designated in their markings as "S.F. 14Z G.i." The G.i. stood for "Gitterplatte" and these models could be seen with either the grid or L-shaped reticle pattern.


Featured Examples:





S.F.14.Z.Gi, H/6400 . Excellent example of complete tripod assembly for open field use. (From Paul Wills)


Detail of Serial Number and Identification markings (Paul Wills)


Front and back views (note eyepiece openings - attachment areas for shades)


The view of the "Gitterplatte" through the right lens of the SF 14Z Gi. (Paul Wills)





Earlier Zeiss manufactured SF 14 from 1934


Wartime image of distant Pzkfw V Panthers taken through the right lens of a SF 14Z Gi, presumably from another tank or observation position. Even with age, this photo still suggests the SFs ability to relay images of detailed relief of distant objects and terrain, especially that of the apparent and measureable height of the causeway on which the tanks are resting. One can also see panzergrenadier troops cautiously
crawling towards the top of the causeway toward the protection of the Panthers.


Detail of same image.

"

SF mountings in vehicles were attached in various ways, including hand-cranked devices or simple lock-down levers. In any case, the delicate optics had to be taken down quickly in some way and stowed once their primary job was done, and the enemy to be engaged in close combat. Most vehicles had specific stowage boxes or cases built in to the interior of the fighting compartment for quick retrieval or stowage of these SFs.


SF 14Z Gi manufactured by Emil Busch A-G, Optische Industrie, Rathenow for military vehicle use. Almost all accessory optical devices made for vehicles, including tanks, were factory finished in a common sort of "field yellow" or "dunkelgelb". This color was not necessarily confined to use by the Afrika Korps which is a common mistake. DAK troops would, however, paint field-grey factory finished optics in this color.


Rear View



Front View


View through left lens


View through right lens displaying the unique reticle pattern.


This particular SF was field-painted in the dunkelgelb scheme after arriving in theater. Directly above the interpupillary adjustors and bubble level in the center can be seen the special bracket to which the forehead pad would be installed.


SF14Z Gi H/6400 manufactured by Hensoldt & Sohne Optische Werke A-G, Wetzlar, Germany showing the forehead pad installed for vehicle use.


Detail of forehead pad.






Tank commander of Jagdpanzer IV at his station. The SF 14Z is attached to the inside portion of the tank commander's cupola via a bracket (Verlinden Publications).


Above view looking down on the SF mounting position, and another of the tank commander at the same position (Verlinden Publications).


Crewman taking down SF to install or detach for maintenance. To the left and lying on its side is the SflZF 1a, or main cannon gunsight awaiting its turn to be re-attached to the ranging drumwheel assembly inside(Verlinden).




Crewman looking through maingunsight. SF mounting and crank-operated elevation assembly is seen right behind him as it extends out the commander's hatch. (Verlinden)


Clear inside view of the SF's mounting inside the JagdpanzerIV. The SF is attached to the central spindle and cranked up and down to elevate or lower the SF on it's track.(Verlinden)



On the "down-low". SF cranked down to enable observation without exposing the head or upper body to gunfire. (Verlinden)




SF mounting on Henschel King Tiger.(Panzerbasics)


Closeup of SF mounting in Henschel King Tiger commander cupola.(Panzerbasics)


Detail of SF mounting looking down on Henschel King Tiger cupola. Clearly seen is the lockdown lever at underside right. While not as sophisticated as the mounting on the JagdpanzerIV, It could be surmised that the unit could be torn down quickly enough.(Panzerbasics)


A view from the front of a Nashorn facing the back as the crew loads ammunition, the SF is seen on it's swing-away mounting on what appears to be a typically horrible winter day on the Ostfront.


More views of the swing-out mount on the same Nashorn.


The SF peeks out above the top of the Nashorn


From the fighting compartment of a Sdkfz 251/10 armed with the 3,7 cm PaK, a Landser takes final measurement of the objective and searches for targets before the crew moves into the next position for firing. He appears to be using the smaller 6x30 version of the SF.


Searching the plains. A Pzkwf V Panther Ausf G commander surveys the limitless plains.


The SF mounting in the Stug III.


Back inside the Stug. The commander and gunner sat in very close proximity to each other and pretty much in line with the driver. The commander's SF14Zgi is directly in front of his face.


Another inside view of the SF14Z mounting, now in use. The SF14Z itself could be rotated 360 degrees and could also be easily and quickly dismounted and used outside the vehicle...



...like so.

The Scherenfernohrs (SF) - Part I: Background

Background

There seem to have been a couple of different stereo binoculars used in German AFVs in WWII, but the SF 14Z that was normally used in the Jagdtiger was probably the most common. These optical instruments were a development of commercially available binoculars manufactured by Zeiss before the war. In Germany they were called "Scherenfernrohr" or scissors telescope (Zeiss called them "Relieffernrohre,"), but they were not a commercially successful product for the company when sold to the general public. An 8x20 model was offered from 1894 to 1906, and a 10x25 model from 1895 to 1908. This is probably the design that was later bought in vast numbers by the German military and used in both World Wars with little change.
Viewing an artillery barrage through the lens of the SF 14Z

Typically, these binoculars provided spectacular views of terrestrial objects, greatly magnifying the perception of depth in a scene as well as the appearance of modeled relief. They were also used as rangefinders in both wars by several service branches of most of the participants in the conflict, particularly the Germans. The smaller hand-held scissors periscopes were about 6x30 power, with objectives that could extend to 18 inches, and the usually included a folding hinge to reduce the overall length for transport. Larger tripod mounted instruments sometimes had 50mm objectives, very helpful for use at dawn and dusk, and these larger periscopes were the ones typically found in armored vehicles. The SF 14Z had a magnification of 10x, a field of view of 5 degrees, eye relief of 12.5mm, and inter-ocular distance of 57mm+ as stereo, and 58mm+ as periscope. Normally, the graticle in the right eyepiece showed 10mil squares with 2mil gaps at 5mil intervals. There was an interrupted cross at the center for the datum or aiming point. The graticle could be illuminated by an internal light bulb, and it also incorporated a small clinometer that was also graduated in mils. A wing nut on the bracket allowed the periscope to be elevated to a comfortable position for the commander.
From Seeger:

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.) 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. 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' (for 'Gitterplatte'). From the outside, the two models are indistinguishable. The grid plate, (see my following posts) 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 acquisitions. 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" or 'angle of sight' adjustor 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. 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.

Next: Technical Description and Operation

A Foolhardy Undertaking

Greetings.

Military optics, specifically those manufactured in Germany during the First and Second World Wars, hold a special fascination for collectors and historians alike. Famed manufacturing giants such as Zeiss, Hensoldt, and Goerz, among many others created a level of craftsmanship, quality, and pinpoint precision, that even today cause one's jaw to drop in awe when viewing a distant objective with the unparalleled clarity of these devices. It was this level of precision (still debated all over various military history related internet forums) that caused a focused heightening of the Allies' engineering and production level of effort to catch up to the perceived better quality that the Wehrmacht possessed.

I am now attempting (foolishly) to put together what I consider to be a much-needed reference to German military optics. There just is so very little available both on the internet, and in printed form. It just seemed to me with all the "tank-freak" sites and forums that feature endless soliloquies on engine speeds, turret rotation time, armour penetration, and cannon size, no one ever gets into the details of the optics - - the true eyes and soul of the system. After all, it is the optics (and related hardware) that ties the man and his intentions to the machine, is it not?

Why do we lack reference information on these optics? Well - many of the German handbooks and manuals - namely, the "Heeres Druckvorschriften" and "Merkblatt" series to name only two - simply did not include the kind of detail that we desire today. Nor did these series follow any logically consistent format (the U.S. manuals of the day also suffered similar shortcomings). For example, for all the numerous manuals describing the proper loading of equipment for transport on the backs of camels or the proper concentration of chemicals for photographic developers, there was frightfully little in comparison on the type of optics that were used for a particular sort of weapon, where it was located on the weapon, how it worked in conjunction, what it looked like, and what you saw when you put your eye up to it - and what you were supposed to do with that image. Secondly, documentation material for optics (not to mention many of the optics themselves) were destroyed after the First World War, along with the fact that many of the manufacturers preferred to not publish documentation at all even during that war. During World War Two, Allied intelligence organizations began collecting information on their foe's optical advances. Then at the end of the second war, as the Third Reich fell, many of the engineering labs and factories not already destroyed by bombing, were ransacked by conquering Allied and Soviet forces - Western and Soviet intelligence operatives, now rivals, began scouring and locking away any and all evidence of nazi technology and weapons-related optics for examination to be used against each other if necessary in the newly dawning Cold War. Suddenly, German military optics became top-secret information.

So now we must act as archeologists, piecing together what we can, and hope to come across the odd manual, handbook, or instruction that points to the right answer. I also have relied on the good graces and generosity of militaria collectors and dealers who have provided me photographs of their stock in trade and in some instance, even a photograph of the internal reticle, crosshair, or optical scales - which to me is the ultimate "holy grail" of any optic device of the Third Reich. I have also been blessed to have received crucial help from a number of museum curators who share in the same passion to discover these treasures of military history. Necessity truly was the mother of invention. To wit, I will provide the names (or assumed names) of those who have provided me the photographs to offer proper credit. I will also provide the literary reference where applicable. I will also provide the names of any website, when possible, from where I received the information - my intent is never to knowingly steal. If one owns credit on a photograph, please inform me and I will heartily modify the content to reflect the ownership.

I will organize these items by type and family to the best of my ability. It will be constantly updated and added to. I may switch things around without warning, to accompany proper classification, or to correct my own ineptness and ignorance, of which I am in no short supply. And yes, I plan to write a book someday.

So to maintain at least some sanity - I will focus on a particular "family" per month. For the month of September, all postings will be on the the Scherenfernrohrs, etc.

That said, let us begin. I show you now what I have dredged to date. The journey continues...

Next: The Scherenfernrohrs - Part I: Background