Telescopic gunsight exactly designed for the gunner. Meanwhile, periscope(panorama) organized for the commander to look around. Logically, commander sight less accurate and has less magnification, but good FOV. (This is my point
Also I'd like to add that in SF there are two types of the telescopic gunsight:
- unmovable (early one, which is extremely uncomfortable for the gunner. This gunsight consist of one part and attached tough to the gun. Means, head of the gunner should follow for the binocular each time when barrel goes up/down)
- movable/flexible (late one. This gunsight consist of two parts. One attached tough to the barrel, second to the working place of the gunner. Means, head of gunner is always on the the same position near binocular and independent from the barrel position)