On side note, in SH3 or SH5, it’s quite easy to set right AOB just visually by the TDC ship shape drawn on the TDC in regard of what you see in periscope.
I usually got very good results.
I proceeded same way in SH4, but my AOB is not that accurate as in SH3/SH5
The ship shape drawn on TDC looks like the boat is coming more toward me than it is in reality...so best is to set AOB when ship is pretty close to 90°. It’s easier and more accurate. At least to me...
(Sorry for bad explanation, i’m Not English native)