[joegrundman]

It was the main reason the germans used the Attack Periscope instead of the obs scope which didn't have that

actually it's possible that in the early war all scopes included the AOB finder. The real reason for using the attack scope was the smaller head and therefore smaller feather wake and reduced visibility of the attack scope.

I think the obs scope was sufficiently good at light gathering to permit stellar navigation.

The important info in this is that you could not see through the scope unless it was fully raised.

if this is true, i don't see how it is deduced from the text you quoted just before. Could you please explain or else cite the document you sourced this information from?

The "2d" perisope view should be completely clear, and no, they didn't have periscope lines which changed color during the night.

Are you sure about this? I have repeatedly come across references to radium being used for the scope reticule (as is used for the glow-in-the-dark marks on an analogue wristwatch). Can you link to your reference for this, please?

Now the AOB dial was in fact linked to both the Bearing dial AND the compass

yes this is what i was getting at in the previous post - is it possible for you to link to your reference for this too

this would really help, as it is important and ought to be implemented if demonstrably true

best wishes

joe