History of microdot. Article updated 13.04 in 2023.

THE HISTORY OF THE «MICRODOTS»
«Microdot» during the «Cold War»

(End. Beginning in 4, 5, 1999)

After the end of World War II, the former allies began a real hunt for German technology. First of all, this concerned specialists in the field of rocket technology. The father of the «weapon of vengeance» Wernher von Braun and many of his employees ended up in the United States in the research complex in Huntsville.

On the other hand, the first Soviet ballistic missile R-2 and its civilian geophysical analogue B-2 were very reminiscent of the infamous V-2.

A similar situation developed in the general (photography enthusiasts of the older generation remember the magnificent camera «Kyiv» of the Arsenal plant, which practically repeated the pre-war Contax-II of the Zeiss-Ikon company. In 1947, 500 copies with ZK 2/50 mm lenses (Sonnar-Krasnogorsk) were produced from German parts. Since the end of 1949, the «Kyiv II» version (50,000 per year) was produced entirely in Kyiv. It seems to us that there is nothing offensive in such borrowing. For example, the Japanese company Nikon, now known for its SLR cameras, until 1959 produced only rangefinder cameras of the I (1948), M (1950) and S (1951-1960) series, surprisingly similar to Contax.) and special photography. In this regard, the fate of Helmutt Frieser, a specialist in physical chemistry and associate of E. Goldberg, the creator of the genuine “microdot,” is of interest. From 1937 to 1945, H. Frieser studied the problem of increasing the resolution of photographic emulsions at the Agfa company in Leverkusen. After the war, fate threw him into the Soviet Union for 10 years, where, like other German specialists, he worked in a so-called “sharashka” and dealt with issues of microphotography. In 1955, H. Frieser returned to Germany and continued working at the Agfa company.

Later in his works he made a number of interesting observations that shed light on this previously unknown page in the history of microdots. Thus, in an article published in Vienna in 1956 and devoted to the problem of increasing the resolving power of light-sensitive emulsions used in microphotography (Frieser, Helmutt, “Resent Studies of Small Details in Photographic Emulsion” Wissentschaftliche Fotografie, 1956), H. Frieser refers to the early works of Soviet and Czech researchers. It was obvious that at one time he had to work together with them on this problem.

During the Cold War, the number of official confirmations of agents using microphotography dropped sharply. However, the press and cinema more than compensated for this “loss.”

Whenever information about intelligence activities becomes public knowledge, it is usually mixed with a fair amount of disinformation. Such are the laws of the genre: no intelligence agency in the world ever fully reveals its cards, even in cases of days long past.

In a confrontation between special services, it is always necessary to keep the enemy in a state of certain tension. Often so much fog is created that even the direct participants in the events sometimes find it difficult to figure out where the facts are and where the fiction is. Well, if we add to this some “literary processing of journalists, who write with rapture about the spy zoo”, consisting of “bugs”, “bugs” and moles”, then all that remains is to take off one’s hat.

The same thing happened with the microdot. Over time, the process of its production, and even more so its operational use, has become overgrown with various legends, some of which are deliberate disinformation, while others are the fruit of the imagination of not fully prepared, and, in fact, technically illiterate, would-be specialists.

The first mention of the use of microdot in the 1950s was the assertion that information about the supply of Czechoslovakian-made weapons to Guatemala in 1954 was received by the US State Department in the form of a microdot (Tulli, Andrew, CIA, The Inside Story, William Morrow: N.Y., N.Y., 1962).

But the most colorful description of microphotography was given by the Western press when covering the trials related to the failures of Soviet illegals. Behind each such dramatic story, as a rule, stood the meanness and betrayal of auxiliary agents, and thank God that in many cases it was possible to rescue these selfless people.

When the materials related to the case of the famous Soviet intelligence officer Rudolf Abel became public (Colonel R. Abel was arrested in New York after his assistant Reino Heyhagen, en route from Europe to the United States, showed up at the American embassy in Paris on May 6, 1957 and betrayed his boss. R. Abel was later exchanged for F.G. Powers, the pilot of the American U-2 reconnaissance aircraft shot down near Sverdlovsk on May 1, 1960), in addition to the Exakta SLR camera, they also mentioned special high-resolution Kodak High Resolution Spectrographic (HR) Type 649 photographic plates, which in no way can be classified as materials for amateur photography. No special devices or accessories were found, at least this was not stated. But the connection with photomicrography was clearly traced.

In the numerous spy scandals that took place after the R. Abel case, microdots were not mentioned. Only in the case of the Swedish Air Force Colonel Stig Wennertstrom, who collaborated with Soviet intelligence in the 50s and 60s, was it mentioned that he received instructions in the form of microdots. S. Wennertstrom actively used microfilming to transmit military secrets.

Various photographic means also figured in another case related to the Portland Group — «Portland Ring». Its leader (resident) was the famous illegal Konon Trofimovich Molody — Gordon Lonsdale (photo 1), from whom the image of the Soviet illegal in Savva Kulish's film «Dead Season» was amazingly accurately copied.

Photo 1.

On January 7, 1961, Scotland Yard arrested K. Molodoy’s assistants – the family of Helen and Peter Kroger (aka Morris and Lona Cohen in the USA, wanted by the FBI in the Rosenberg case of transferring American nuclear secrets to the Russians). Subsequently, K. Molodoy and his assistants, the Krogers, were exchanged for Greville Wynne, an English businessman convicted in the USSR in the O. Penkovsky case), who by that time had many years of successful illegal work behind them. Several cameras and a large number of various photographic materials were found in a hiding place in the bathroom. We will not bore our readers with lengthy descriptions from publications of that time (Norman, Bruce, Secret Warfare, Acropolis Books: Washington D.C. 1973). Like all such stories, they contained a lot of absurdities, which were later noticed by Western specialists in the field of special photography (William White, The Microdot History and Application, Phillips Publication, 1992).

But one significant detail was noted by Peter Wright (1916 – 1995) himself, a leading technical specialist of the British counterintelligence MI-5. He was the first to understand the principle of operation of the listening device in the carved wooden coat of arms of the USA, implanted by the Soviet secret services in the office of the American ambassador in Moscow in the early 50s (see the magazine “Special Technology” No. 1-2, 1999)), a famous spy hunter. In his memoirs (Wright, Peter, Spy Catcher, Viking Penguin Inc.: N.Y., N.Y., 1987 pp. 137-138), mentioning the arrest of the Krogers, he writes:

“…Despite the clumsy work of the police officers who conducted the search, it was obvious that the house was literally stuffed with spy equipment. Two sets of different cipher pads were camouflaged in a cigarette lighter similar to the one used by G. Lonsdale. Also found were tables for receiving messages from Moscow on three different channels, means of secret writing, and accessories for making microdots: chromic acid salts and cellophane.

Mrs. Kroger tried to destroy the conditions for communication with other agents by throwing the contents of her handbag into the toilet, but was stopped by an alert policewoman.

But the most interesting find, without a doubt, was the plan for high-speed radio communication with Moscow. In a biscuit tin we found a bottle of magnetic powder that made it possible to make dots and dashes on the magnetic tape used for high-speed radio transmission visible to the naked eye. This eliminated the need for a complex special tape recorder for slow-motion playback of received and transmitted messages.

For us (referring to British counterintelligence. — Author's note) this was a completely new and original means. Now it became clear why, for several months before the arrest of the Krogers, we had not managed to intercept a single one of their sessions…

We searched the house for nine days and finally found the transmitter. It was hidden in a secret compartment under the kitchen floor along with several cameras and other photographic equipment. Everything was carefully packed in waterproof bags and, no doubt, could be stored for a long time.”

Speaking of the microdot, it is worth mentioning Robert Thompson (photo 2), a US Air Force serviceman arrested in 1965 on charges of spying for the USSR and sentenced to 30 years in prison (in 1978, R. Thompson was exchanged for an Israeli pilot captured in Mozambique).

Photo 2.

There are many unclear details about his case. During his arrest and during the investigation, he presented at least three different versions of his involvement with Soviet intelligence. R. Thompson's story was repeated in the press many times in confessions such as «How I Spied for the Russians» (for example, in the «Saturday Evening Post»).

According to some sources, he was born into a poor priest's family in 1935 in Detroit. But during the trial, it was revealed that he was born in 1925 in Leipzig. After the war, he was interned in the USSR along with other members of the Hitler Youth youth organization, where he found himself under the care of the secret services, underwent appropriate training, and was sent to the United States as an illegal.

And although R. Thompson was quite well prepared, he apparently was not a source of valuable information, but played a supporting role. The attention we pay to his testimony is explained by the following. Perhaps this is the most complete description of the method of making a microdot used by Soviet intelligence agents and published in the Western press. As it turned out during the investigation, R. Thompson was trained in Moscow in the use of secret writing, as well as microphotography, including with the help of a Minox camera.

When he was arrested, his Minox B camera and a container in the heel for storing the exposed microfilms were confiscated (according to established practice, to reduce the volume of the insert, the empty part of the cassette was broken off, and the receiving part with the exposed film was placed in the container).

According to R. Thompson, in the Soviet Union, in addition to microfilming, he was also taught how to make microdots. Here is what he himself said about it.

“The document to be reduced was re-shot using a 35 mm single-lens reflex camera (to make the intermediate negative, R. Thomson used an Exakta SLR camera made in the GDR – a legendary high-class camera, a true work of engineering art). To do this, it was enough to place it on a flat surface, fix the camera to the back of a chair with a clamp and, very importantly, organize uniform lighting of the original. After development, the intermediate negative was clamped between two glasses like a regular slide.

At the same time, a light-sensitive material was made from a piece of ordinary cellophane using special chemicals supplied to the agent by his handlers.

A sheet of white paper was placed on a horizontal surface, onto which a special device was installed, let's call it a microdot camera or a microcamera (in his testimony, R. Thompson described it as a small bronze tube 35 mm long, inside which some special optical system was placed). Parallel to this surface, at a height of 60 — 80 cm, an intermediate negative was placed, clamped between glasses. An ordinary magnifying glass with a power of 2.5 — 3x was placed on it, acting as a condenser. An electric lamp with a power of 100 W with a transparent bulb was installed above the negative.

This entire structure was adjusted in such a way that the light from the lamp was concentrated by the magnifying glass and, passing through the negative, was collected in a narrow beam in the lens system of the micro camera. By raising and lowering the glass with the negative, it was necessary to ensure that the beam of light was collected in a point on a sheet of white paper. This place was marked with a cross.

After this, the lamp was switched off. A piece of cellophane prepared in the manner indicated was placed on the place marked with a cross, and a micro camera was placed on top of it (since the light-sensitive layer for making the micro dot had very low light sensitivity, the above manipulations could be performed in dim room lighting). The lamp was switched on again and an exposure was made, which usually lasted 3 minutes. The exposed photo layer was developed in a regular black-and-white developer. The image was a microscopic black dot (according to R. Thompson, the usual dimensions of a micro dot were 1×1 mm. No complex optical devices were required to read it, and at the same time it was easy to hide in mailings and other suitable objects).

Using a piece of a razor blade with a broken off sharp end, this dot was cut out and hidden with special precautions in a certain place previously agreed upon with the agent (according to R. Thomson, each agent had his own previously agreed upon place where he would paste the microdot). Usually, an ordinary postcard was used for this. Its corner had to be split into 2-3 mm (photo 3), the microdot placed in it and glued with glue made from ordinary flour. Unlike other types of glue, it did not have a luminescent effect in ultraviolet rays and did not create unmasking signs. Various containers in small household items could be used to store the microdots (photos 4, 5). To read the microdots, a small microscope (photo 6) or a special device, camouflaged even in a cigarette (photos 7 – 8) was enough.”

Photo 3. Device for splitting the edge of a postcard

Photo 4. Ring with a container for storing and transporting a microdot

Photo 5. A coin container for storing microdots

Photo 6. A pocket microscope that can be used to read microdots

Photo 7. A portable device for reading microdots

Photo 8. A miniature device for reading microdots, which could be camouflaged in a cigarette.

The device for making microdots described above, for obvious reasons, did not fit into the general range of household items, and had to be stored in a special container. An ordinary battery for a pocket flashlight was used as it.

To make it more convincing, a real small battery was placed inside the container, the voltage from which was supplied to the contacts of the large battery-container. Thus, it seemed that the container was an ordinary power source. Of course, it could not be used for its intended purpose due to its small capacity. But externally, it did not arouse suspicion in those around. In order to open the container, it was necessary to press on its wall in a certain place and unscrew it. The container was made so carefully that R. Thomson sometimes confused it with ordinary batteries.

There were many contradictions, omissions and even absurdities in R. Thomson's testimony. But there could also have been deliberate distortions by «counterintelligence editors». In any case, it remains unclear how he managed to obtain high-quality microdots in such a simple way, if E. Goldberg himself needed a complex optical design for precise focusing. Apparently, the agent's task did not include obtaining high reduction ratios.

Of course, the Soviet secret services used in their developments the well-known achievements of the “fathers” of microphotography. But in any case, one can only bow in respect to the skill of the Soviet technicians”, who supplied R. Thomson with such a simple-to-use and such perfect in quality special technical means for producing microdots in “field conditions”.

A few words in conclusion. Obtaining microcopies of documents is usually associated with a Minox camera on the now forgotten 8×11 mm format and on 9.5 mm wide film. In this case, a reduction of only 35 times was achieved.

But few people know that for the same purposes it was possible to use an amateur 8 or 16 mm movie camera with a good lens and the ability to shoot frame by frame. Some of these cameras even had a sync contact for connecting a flash lamp. As a photographic material it was possible to use AGFA-СOPEX RAPID microfilm film. As a developer it was recommended to use the famous AGFA-Rodinal, which is still produced, diluted hundreds of times (in the author's practice there was a case when NP-10 film produced by ORWO (GDR) was developed in Rodinal developer, diluted 1:200. The development time was 65 minutes (!) with continuous stirring. But the result exceeded all expectations: the negatives turned out to be exceptionally fine-grained with excellent tonal rendition).

Generally speaking, the process of microfilming was described in sufficient detail in amateur literature. Suffice it to say that in the late 1930s, a brochure appeared in America that described in detail how, using a minimum of equipment, to obtain, if not microdots, then very small microcopies of the originals.

In 1943, the book “Entertaining Microscope” appeared. It simply and clearly described the process of making, if not a real microdot, then at least an ultra-microfilm. All this happened in that blessed time when there were no automated photo labs, and there was no photo service as such. Amateur photographers did everything themselves and unwittingly became researchers. In a word, a real “school for young fighters for novice spies”. But it was still a long way from a real microdot: it was at least 10 times smaller.

Let's briefly dwell on other methods of obtaining microdots, descriptions of which appeared at one time or another. Generally speaking, making a microdot is a rather complex task, requiring, on the one hand, specific equipment, the presence of which is difficult to legend in everyday life, and on the other, a fairly high level of professional training.

In the book by Keith Melton (The Ultimate Spy Book, DK Publishing Book, NY, NY, 1996) that we have already cited, the so-called English two-stage method of producing microdots is described, when the intermediate negative was repeatedly reproduced from a distance of 127 cm! (Photo 9). All this looks unconvincing, since it is associated with large losses of illumination (as is known, illumination falls proportionally to the square of the distance from the light source to the object. Remember what E. Goldberg said about this in his lecture in Paris in 1925 (see the journal Special Technology No. 4, 1999)) and resolving power. Apparently, here we are dealing with some surrogate method of obtaining pseudo-microdots.

Only special film for scientific purposes for spectrography and astronomical images HR (high resolution) and concentrated Lipman emulsion are suitable for making microdots. The latter is much more difficult to make and therefore less common, but its resolution can reach 6000 lines/mm.

When talking about microdot, we must not forget that in addition to fine-grained emulsion, one of the essential conditions for successful work is a high-quality lens. Back in 1925, the father of microdot E. Goldberg noted the need to use a microscope lens with a focal length of 20 mm and a flat image field. Such lenses are produced by leading manufacturers of optical devices Leitz, Zeiss, Nikon. They are very expensive, and their presence is typical only for forensic or crystallographic laboratories, but not for amateur photographers.

A serious problem in the production of microdots has always been equipment vibration during long exposure.

Another very specific problem arises from the main property and even advantage of the microdot — its low visibility and extremely small size. A microscopic piece of transparent cellophane is so easy to drop and lose without a trace! Experience shows that if you do not know exactly where the microdot is hidden, or God forbid, drop it on the floor, especially on a carpeted floor, it is almost impossible to find it. Maybe that is why the microdot was used in espionage practice in exceptional cases.

In any case, obtaining microimages with a reduction factor of 1:400 is the lot of professionals from the relevant laboratories of the leading intelligence agencies.

Our story has come to an end. It is unlikely that we will ever learn new details about the use of such an exotic photographic means as a microdot. Intelligence agencies know how to keep their secrets, especially when the interests of the state and the human destinies of “fighters of the invisible front” are behind it.

Of course, one can fantasize about the prospects for the development of this very specific area of ​​special photography. But this business, as we think, is absolutely thankless. On the one hand, the very existence of silver halide photography is a matter of time: the positions of electronic methods of obtaining, storing, processing and transmitting graphic information are becoming stronger every day.

So let's leave behind a certain aura of mystery that has always surrounded the microdot, as well as the entire arsenal of ingenious technical means used by representatives of one of the most ancient professions.