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.