Nice find.
Do the TZF sigths really work this way irl ? :
Yes. There is enough wartime training material available on the subject to recreate firing techinques used with Tzf (Or for that matter any other tank gunsight currently modeled in RO).
What I am uncertain of in terms of the RO game engine is if there is a direct relationship between gunsight scales provided on the sight reticle\graticules graphics we see when we look through our virtual gunsights and the simulated range within the vitual world of the game. In theory if virtual range is accurately modeled and gunsight reticles scaled properly, you should be able to get a pretty good estimate of range using mil scale or strich. UK uses minutes and seconds of degrees -- but same difference. Soviets used a 6000-mil circle -- USA and Germans used a 6400-mil circle.
The simple method of estimating range is via what the US Army calls the WORM formula or WORM Equation. It is sort of explained on the web site posted above. Basically if you know the width or height of your target it is very simple to estimate range to the target using the graticule or reticle provided in a TCs binoculars or a gunners sight picture. The graticule\reticle lines have well defined lengths, heights, and widths in terms of whatever angular scale was being employed by the Army of interest -- 6000mil circle -- 6400mil circle or 3600-minute/21600-second circle.
For example in real life -- lets say you know your target is about 2.5meters in height. You look through your gunsight and determine via one of your verticle reticle lines (or triangles in Tzf) that the angular height of the target is 5-mils. The range to the target can than be determined by the WORM Equation:
(2.5meters x 1000)/5-mils = 500meters.
So the range is about 500-meters.
If the angular height of the vehicle was determined by the TC or gunner to be only say 1.5-mils, than the approximate range would be:
(2.5meters x 1000)/1.5-mils = 1667meters or round up to about 1700m
Can you do this with any consistancy in the game envirnoment provided in RO? That I Don't. If everything is scaled correctly you should be able to do exactly the above -- set your gun range\super elevation to the range you calc'd from WORM Equation; place the cross hair center of mass and have a very good chance of hitting the target.
But The gunsight graphics have to be properly scaled and virtual distance within the playing environment has be scaled correctly.
My hunch has always been reticle scaling and virtual range in the game dont jive with reality -- but it is easy enough to check by setting up a test map. Just an aside, but I have suspected for sometime that the stock RO T34/76 gunsight reticle wasn't calibrated properly. This was sort of fixed in Armored Beasts. But whether or not AB does any better with proper reticle scaling, I do not know.