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Wrong Scalings with Primostar 3 HD IP Cam

Posted: Wed Jun 16, 2021 1:59 am
by Benjamin Ng

There seems to be a problem with the scaling factors when using a Primostar 3 with the HD IP Camera tube in Labscope 3.2 (Windows version, camera connected to PC using USB). Scalebars and measurements are exactly 0.5x the actual value when the correct objective is chosen (we used a stage micrometer to make the measurements). There does not seem to be a way to specify any camera adapter magnifications or "zoom" values when this microscope is connected to Labscope.

As a workaround, there is an "optovar" parameter that can be modified in the "microscope.json" file created in:

C:\Users\<current user>\AppData\Roaming\Carl Zeiss\Labscope3\DefaultWorkspace\Microscope_<serial number>

Modifying this parameter from 1.0 to 0.5 corrects the scaling factors:


Is there something hard-coded in the software or camera tube firmware which is setting this "optovar" parameter incorrectly? Or perhaps there is something wrong with the particular Primostar 3 we were using?

Camera tube serial number : 5722000068
Camera firmware :
Primostar 3 serial number : 3185000116

Thanks for any assistance.


Re: Wrong Scalings with Primostar 3 HD IP Cam

Posted: Tue Jun 29, 2021 11:52 am
by Maik Drabent
Hello Ben,

thank you for reporting this issue.
We have reproduced the problem of the incorrect scaling.
It occurs for Labscope when connecting to a fixed Kohler Primostar 3 HD IP camera.
The other types of Primostar 3 does not have this problem.

It will be fixed with Labscope v3.3 which is coming end of next Month.
Please update your Labscope version after the release.

With best regards
Maik Drabent