Rangefinder values how are they determined?

[chuckfourth]

Hi All
This site amongst others confirms the SF.14Z to be a rangefinder.
http://www.powerhousemuseum.com/coll...images=&c=1&s=

Now these rangefinders are issued to all stugs,
"The gunner's only view was provided by the Sfl.Z.F periscopic gun sight with an aperture in the superestructure front. The commander was provided with a SF.14Z scissors periscope that projected through the opened hatch when in use. When not in use, the SF.14Z mount was folded down and the binoculars strapped to the left wall.
StuG III Ausf G: "The key feature identifying an Ausf.G from its predecessor, the Ausf F/8, is the redesigned superestructure. A cupola with seven periscopes
was added for the commander. When buttoned up, the commander could still observe by extending the SF.14Z scissors periscope through a hinged port cut out of the forward edge of the hatch lid."
Also the hetzer, jagdpanzer IV, and probably also the jagdpanther carry a rangefinder.

Heres a picture of hetzers rangefinder poking out.
http://www.wwiivehicles.com/germany/...zer-photos.asp
For the jagcpanzer IV
here is shown the gunners sight extended
http://www.wwiivehicles.com/dragon/g...jagdpanzer.asp
and the commanders rangefinder extended.
http://www.wwiivehicles.com/dragon/g...jagdpanzer.asp
ie The standard configuration is the gunner has the gun sight while the commander determines the range with his rangefinder.

I Think there is already a jagdpanther with or without rangefinder, units 840 and 053?
Perhaps the stugs and hetzer should also get the 10 rangefinder value of unit 804?
I notice that various shermans get values as high as 6 for rangefinder. AFAIK these vehicles dont carry a rangefinders so Im not sure what the rangefinder value/variable actually represents. Would I be too rude to ask?
Best Regards Chuck.

[noxious]

S.F.14 (Scherenfernrohr 14) is not a rangefinder. It is a simple set of binoculars, just designed to be operated from cover (trench, AFV, behind a tree). The two periscopes can be folded down, resulting in a larger distance between the objectives, making it easier to discern the relative distance between objects viewed. Just like the binoculars used by tankers in other armies, it has a reticle with horizontal and vertical scales that could be used to measure range, similar to those found in the tanks gun sights.
But neither the S.F. 14 nor the binoculars nor the gun sights in tanks can measure range. You can observe distant objects, but in order to measure the range, you have to relate what you see to something which tells you the distance to the objects. It could be a map, on which you can measure the distance from where you are to the object you see, or you could fire at the object with the gun set at a particular range and then observe the fall of shot in relation to the target, then use the scales on the reticle to correct your fire. You can also use the scales to calculate range if you know the size of the target or some nearby object.

Proper rangefinders have means of measuring distance without the observer having to consult maps, know distances or the size of the thing. The coincidence rangefinder works by the observer either aligning or superimposing images. Once the images fit, you have the range. The stereoscopic rangefinder uses the observers depth perception by having him adjusting markings appearing in each eyepiece, that can be moved to fit one another, again returning the range. IIRC the Germans used the stereoscopic system in their artillery rangefinders and in the few late war tanks equipped with rangefinders.

nox

[chuckfourth]

Hi noxious thanks for your reply.
As far as I can make out you are correct in that Scherenfernrohr 14 was not a rangefinder per see but was used as such just as a tankers binoculars could be.
However
Estimating the range is only important at long ranges when the shells arc begins to curve making the elevation of the gun critical in scoring a hit.
the sf14 is going to be much better at estimating long ranges than a tankers binoculars because it has a higher magnification (14) than binoculars(7 or so), and is in a fixed mount within the vehicle, binoculars being hand held.
Sf14 is also steryoscopic which binoculars are not. Hence giving a better/clearer view of the target allowing it to been seen and hence measured against its background and the reticule scale more accurately.

The tank is designed to be used in mass to penetrate a front and then shoot up artillery supply etc, ie their main role is not gunnery its the delivery of shock, requiring speed, range, reliabilty, good vision, and communications, then maybe gunnery. Hence SF14's not issued to tanks. low magnification binoculars are better when you are on the move you are much more interested in whats close by than whats far away.

Sf14 is issued to panzerjagers(listed previously). Even though panzerjagers have tracks and heavy armour they are not tanks they are AT guns. ie Panzerjagers are ideally employed stationary from a "hide" just the same as a towed AT gun. ie their specific purpose is the destruction of the enemies tanks. As AT guns their most important attribute is gunnery. This is improved by the addition of the SF14 as it can be used to estimate long ranges accurately while at the 'halt'.

http://www.redorchestragame.com/foru...d.php?p=270870

The most notable Nashorn ace was platoon commander of 1st company of sPzJagAbt 519, Junior Lieutenant (later Captain) Albert Ernst. On December 23rd of 1943, he destroyed some 14 Soviet tanks in a single day using only 21 rounds of ammunition."

It is interesting to me that shermans can get range finder values of 5 or 6 whereas these vehicles with a sf14 get a 3 or 4? surely this should be the other way around?

also of interest, from
http://www.germanwarmachine.com/phot...ry/3/index.htm

"The 14-power Scherenfernrohr 14 Ziel Gitter, or stereo binocular, served as a rangefinder for the artillery and was a mainstay of forward observers to gauge distances."

There is also an argument that guns with the SF14 should get a longer "effective" range than the same gun without the SF14.

[noxious]

chuckfourth said:
Hi noxious thanks for your reply.
As far as I can make out you are correct in that Scherenfernrohr 14 was not a rangefinder per see but was used as such just as a tankers binoculars could be.

Yes.

It is interesting to me that shermans can get range finder values of 5 or 6 whereas these vehicles with a sf14 get a 3 or 4? surely this should be the other way around?

I dont think there is a strict 1:1 relationship between the vision equipment of the tank and this number. How a gun works in game depends on many numbers working together, I think. Gun accuracy, Fire Control, Rangefinder and perhaps other work together to create gun performance.

What is wrong with StuG-Jagdpanzer gun performance?

"The 14-power Scherenfernrohr 14 Ziel Gitter, or stereo binocular, served as a rangefinder for the artillery and was a mainstay of forward observers to gauge distances."

Yes, you cannot observe 2 kilometers away with the naked eye. So you need binoculars. Obviously.

Nox

[chuckfourth]

Hi Nox
Well I think there is a 1:1 relationship here, or there should be, because we have for the gun,
Accuracy, reflects the flatness of the guns trajectory ie this should correlate closely with the weapons muzzle velocity.
then the vehicle has
Fire control, this is the gun sight and should correlate with the sights magnification, field of view might also be considered.
Rangefinder, this is for a rangefinder surely?
Stabiliser, this is for a stabiliser, A few american tanks had this
So what factor do you think might be included into the rangefinder value here other than the presence and quality of a rangefinder?

Also it appears that in v6 and prior SPCAMO agreed with me, ie all the shermans had a range finder value of 2 However after v6 the shermans get the higher range finder values, ie threes, fives and sixes. For instance in v6 unit 135 in the USA OOB, M4A3 (76) used to have a range finder value of 2 now it is 5. The lower value of 2 agrees with my thinking. I would be interested to know what the reasoning was behind this change?

Regards your last comment my point is that the sf14 can see better, much better than binoculars at 2 kilometers. Hence I believe the sf14 should delever a higher range finder value.
Best regards Chuck.

[PanzerBob]

If you do not like it change it, one of the beauties of the gsme.

Prost!

[chuckfourth]

Hi PanzerBob
Thanks for the advice, but as I only play PBEM I like to leave the game as packaged. I just think to myself maybe the panzerjagers left their periscopes/rangefinders at home today.
However
I am working on the premis that everyone would like the game to be as authentic a representation of the units depicted as possible. If you have a look at my posts you will see that in each one I have a valid point to make. Usually the more esoteric points require some defence.
Best regards Chuck.

[PanzerBob]

Good day, Chuckforth.

I guess the comment was more for those who are unaware of the possibilities with this game. I haven't PBEM in some time, but exchanging OOB's before play is not out of question providing both sides agree to the changes. BTW, I do concur with your RF assessment.

Prost!

[chuckfourth]

One further point would be that the Nashorn (with a range finder value of 8) appears to have the Scherenfernrohr 14 as it "rangefinder" see the last picture in
http://www.ipmsdeutschland.de/Milita..._Hornisse.html
So two points here, maybe all the other vehicles with Scherenfernrohr 14s should also get rangefinder 8?
and
in-game the German 88mm AA gun also has a Rangefinder value of 8 though (as with all german AA) it comes with a 'real' standard 1m rangefinder. Note this rangefinder (I think the "EM 1m R 36") has a magnification of only 8x compared the the Scherenfernrohr 14's, 14x. Now either the Nashorn Rangefinder value is wrong or the Scherenfernrohr 14 can give a range just as good as the 1m rangefinder. Looking at Nashorn's "legendary" accuracy I would go for the latter.
Also the main advantage of using a rangefinder seems to be not hitting moving targets but extending range. This is why the 88 was so deadly in the desert and the 88 and Nashorn on the Russian steppe, It could hit a target accurately at a range where none of the oppositions direct fire weapons had any hope of hitting them. This seems to be because of the rangefinder/Scherenfernrohr 14.

As far as the "too high" rangefinder values for shermans see
http://www.fprado.com/armorsite/Zeiss_Optics.htm

"The americans had poor optics and could NOT measure the range through them. All shots beyond 800 meters were lucky guesses on their part."

and before you tell me this guy is rubbish, check another of his pages,

http://64.26.50.215/armorsite/tiger1.htm

Also of interest I have a little book which gives these effective ranges for AT guns.
______________________________________in game range
2.8 cm Panzerbuche 41_______500m_______1250m
37mm AT gun M3___________457m_______2000m
37mm Pak 35_______________600m_______2000m
40mm 2 pdr________________1000m_______2250m
47mm Model 01 (Jap)________1000m_______2500m
57mm 6 pdr_______________1500m_______2500m
50mm Pak 38______________2500m_______2500m
75mm Pak 40______________2000m_______3500m
76.2mm Model 1942 (rus)____2000m
88mm Pak 43/41___________4000m_______4500m
12.8mm Pak 44____________3500m_______5500m

In the game it looks as though ranges are determined by calibre looking at the above table it would appear that muzzle velocity (in-game value "accuracy") multiplied by weight of shot (times a factor) or perhaps something similar, would be a better indicator of range for direct fire "AT" guns, tank guns etc than calibre.
The table suggests to me that generally ranges are a bit too high.
Best Regards Chuck.

[noxious]

chuckfourth said:
One further point would be that the Nashorn (with a range finder value of 8) appears to have the Scherenfernrohr 14 as it "rangefinder" see the last picture in
http://www.ipmsdeutschland.de/Milita..._Hornisse.html
So two points here, maybe all the other vehicles with Scherenfernrohr 14s should also get rangefinder 8?
and
in-game the German 88mm AA gun also has a Rangefinder value of 8 though (as with all german AA) it comes with a 'real' standard 1m rangefinder. Note this rangefinder (I think the "EM 1m R 36") has a magnification of only 8x compared the the Scherenfernrohr 14's, 14x. Now either the Nashorn Rangefinder value is wrong or the Scherenfernrohr 14 can give a range just as good as the 1m rangefinder. Looking at Nashorn's "legendary" accuracy I would go for the latter.
Also the main advantage of using a rangefinder seems to be not hitting moving targets but extending range. This is why the 88 was so deadly in the desert and the 88 and Nashorn on the Russian steppe, It could hit a target accurately at a range where none of the oppositions direct fire weapons had any hope of hitting them. This seems to be because of the rangefinder/Scherenfernrohr 14.

Perhaps designers thought Nashorn also had a "real" stereoscopic rangefinder available? They were sometimes carried in Tigers as well (not standard!)

As for the Scherenfernrohr, everybody had it. It is just pretty binoculars.

As far as the "too high" rangefinder values for shermans see
http://www.fprado.com/armorsite/Zeiss_Optics.htm

"The americans had poor optics and could NOT measure the range through them. All shots beyond 800 meters were lucky guesses on their part."

and before you tell me this guy is rubbish, check another of his pages,

It is rubbish. Just because he can copy data from some books does not make him clever.

The Sherman sight had no fancy triangles, but it had lines in reticle which were 5 mils wide and separated by 5 mils space. Not really any different.
Sherman gunner had much better vision to find target, Tiger gunner only had narrow view in his telescope. So Sherman also had advantages.

But Chuck, you know so much about how game should be, so why not make you own game?

Nox