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Sublime

Help me CM community - Need Info on Tank Optics

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I need references and sites with info on german tank optics

specifically superiority to allied optics and why,

and why argon gas mattered

thank you

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thanks wicky

do you remember the thread where they discussed argon gas and its influence on optics?

Further, do you have examples ( ive read them but cant find them quick enough) where alllied tankers looked through enemy scopes and got demoralized?

Its said the sight picture was noticeably clearer. Id like evidence for that too

Thanks brother

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also this is because of a huge argument on quora.

an OP basically claimed I was wrong to say the SS were a bunch of war criminals because 'your judging them only on their wartime behavior'  WTF!? LMAO

Anyways, Im debating, and its friendly and this guy I presume is russian jumps in.  he immediately accuses me of trying to censor the other guy and not allow him free speech. Which is false ( i can link thread)

more ironically he began abusing the report function to try to censor my answers

Annways SOMEHOW optics came up

and he claims their optics werent special, and further he claims to have looked through a german sight and russian one and said the T34 site was superior....

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1 hour ago, Sublime said:

do you remember the thread where they discussed argon gas and its influence on optics?

?? What thread - Argon and it's important application in German gun sights is in the link I posted

 

.... The reflection of a polished glass surface is about 4%.  In the 19th century it was observed that weathered glass surfaces have a lower reflection than fresh polished glass. It was found this effect could be produced through an etching process. But, it was several decades before the understanding why it worked. A thin surface layer with a lower refractive index than the glass reduces the reflection through interference at the surface layer. Lower reflection means higher light transmission.   Another 4 percent of the emergent light is lost by reflection at the inner surface.  Thus, both reflection and refraction (the bending of light) occur at any optical interface. In an optical system with many lens to air surfaces a clearer view is had by reducing light reflection and increasing light transmission.  TM 9-258 Elementary Optics[PDF]


The development of producing lenses with these thin layers occurred almost at the same time in Germany and the US.
Milestone discoveries:
1935 Zeiss, Olexander Smakula inventor - German Patent claimed on vapor deposition of CaF2.
1936 Strong, CaF2 layer formula specified. The reflection reduced from 4.25% to 0.6% using this type film coating.
1938 Cartwright and Turner published a whole class of usable materials including MgF2 and Cryolite (Na3AlF6, sodium hexafluoroaluminate).
1940,1941 Zeiss, Schott and Steinkeil, experimented with double and triple layers; double layers never got into production in Germany or the U.S until after the war.

In WWII Germany the chemically inert Argon gas was used (as it still is) as a "carrier" in electrospray ionization which allows the deposition of ultra-thin coatings. Through bombardment with Argon ions, the material (Cryolite) gets sputtered*. The great advantage of this method is, that it is a cold procedure, where the film material doesn't have to be heated. It was kept as a military secret until after the war.
The result is that light transmission which normally lost 4.25% light per lens surface could only lose as little as 0.6%. Telescopic sights had around 10-16 lenses so this decrease in light transmission could really add up.  (In reality this is progressive since calculations of light loss per surface would go 0.992 x 0.992 x 0.992 x 0.992 ….)

*Sputter- A momentum-transfer process where ionized Argon gas is accelerated towards a negatively biased target and the ions dislodge (sputter) particles from the target to deposit on the substrate.

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1 hour ago, Sublime said:

and he claims their optics werent special, and further he claims to have looked through a german sight and russian one and said the T34 site was superior....

Again the link I posted - seems it would depends on what sight it was for and when it was made 

Quote

Early Soviet sights were better designed than early US and UK sights. A Russian report on an unsubstantiated US report (see definition of 'hearsay') says the sights on the T-34 sent were the best constructed sights some engineers at Aberdeen had ever seen (at least up until when the T-34 was tested during the summer of 1942 through spring of 1943).    Prior to the war the Soviets purchased an obsolete Zeiss plant and technology though the resulting sights produced were only of adequate quality. (Rifle sights made with this machinery appeared by 1932.)  The Germans and Russians had a falling out and by the end of 1933 they ended their military co-operation.  It might be reasonable to assume this technology transfer didn't include the lens coating inventions of 1935 and 1936.   An example in poor light transmission was the Soviet sights on the model T-34s.   Preliminary Report No. 2/0 Feb, 1944 on the T-34 the British made concerning the sample T-34 model 1942 (produced spring or summer 1942 at factory #183 in Nizhniy Tagil.) tank the Russians sent them.  The 2.5 x telescope sight has a light transmission of 39.2% and the 2.5 x periscope dial sight only of 26.3%.    As the war progressed it looks like the Soviets improved their design with the addition of the mili-radian feature of German sights.  Finnish evaluation of T-34-85 sight. "Observation devices: the refractive telescopic sight is greatly superior to the sight of the model 1942-1943 T-34 tank. The clarity of the sight is on the level of the German 75 mm model 1940 gun. The field of view was increased by 15%. The markings are more convenient when firing on tanks up to 1000 meters."

Edited by Wicky

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