“How can I place a observer on a slope? Only by using the “following mode” and then switch back to normal view mode and store the position?”
There are several possibilities:
Choose your position with the cursor and the page up/down keys ( you must be in F5 or F6 mode for this).
By pressing “D” you can bring the model to your place (it is best to go to pause mode at first).
Now you can do some more fine tuning with the cursor keys.
If the position is as desired press F3 and all positions are stored. After a crash or F4 the positions are recalled.