"Visibility from the tank
The IS-3 tank is equipped with the following observation devices:
RGASPI 644-2-464
The IS-3 tank is equipped with the following observation devices:
- Telescopic TSh-17 articulated sight
- Seven periscopic observation devices
The observation devices have the following visibility and dead zones:
- The telescopic articulated TSh-17 sight installed to the left of the gun has:
- Field of vision: 16 degrees
- Magnification: 4x
- Dead zone: 7.5 meters
- The gunner's periscopic observation device installed on the roof to the left of the TSh-17 sight has:
- Visibility through the device:
- Vertical: 12 degrees
- Horizontal: 36 degrees
The visibility through the sight is limited by the opening in the turret. - Two commander's periscopic observation devices installed in the rotating tank turret hatch:
- Visibility through the device:
- Horizontal: 42 degrees
- Vertical: 10 degrees
- Visibility through the device with moving the head:
- Horizontal: 58 degrees
- Vertical: 20 degrees
- Visibility through the device with rotation:
- Horizontal: 360 degrees
- Vertical:
- Forward: 25 degrees
- Right: 18 degrees
- Back: 21 degrees
- Left: 32 degrees
- Dead zone:
- Forward: 10-16 meters
- Right: 19 meters
- Back: 11 meters
- Left: 7 meters
Both of the commander's sights have identical range and dead zones. The variable dead zones in the front, rear, and right parts of the field of view are explained by the geometry of the turret and the rotating portion of the roof."
All of this data is helpfully visualized in a diagram, which also includes data for the loader and driver, who are omitted from the text description.