My dishes collection

[AtOM13]

That I call LNB focal point, is a point just behind LNB 's cap when I've got the best signal possible. The other point is the deeper point of the sub focus.

 

[RimaNTSS]

LNB focal point

I see. In fact, LNB has not focal point but phase center. The main reflector (in your case, CM 120) has a focal point. SUB has 2 focal points.

 

[Channel Hopper]

Ok, lean is corrected.
Still at 80% SQ on 4.8e with the weakest frequency ( 11747 V ) without Fibo.
Haven't time to check performance with Fibo, but I take another picture with Fibo Sub and feedhorn, LNB focal point is 14cm from the middle of the subView attachment 157833

Whilst it is not absolute, most domestic Gregorian satellite systems will have the faces of the two reflectors more or less parallel to each other (since it keeps the feedhorn from creating a shadow) Can you take a picture (far away) of the side on view ?