Periscope, most modern subs ( WW-2 to date) have two, it is known now that submarines used by the Royal Italian Navy had an auxiliary zenith oriented periscopic theodolite/sextant that could be used to take fixes on celestial objects while at scope or siphon depth- also useful in tracking hostile aircraft- this aimed straight up, and was used mainly on Italian subs. Device was evolved by the Officine Gallileo or Gallileo Office- in Italian Officina is more like workshop or craft-assembly a small unit ( but high quality) shop- not a big mass-production factory. Of course on the surface sub officers and lookouts keep the watch with- Binoculars and these days some specialized night vision scopes...
The submarine's periscope and radar mast are damaged.
When at periscope depth, they look through the periscope. It is a prism arrangement that allows good vision around the area. It also provided for gauging distances with a built in range finder.
a periscope
The view through a submarine's periscope was just like looking through an optical telescope - it needed light to enter the lens to allow the user to see in detail what was in front of the periscope.
The object used to view the outside from inside the submarine is called a periscope.
Periscopes allow a submarine, when submerged at a shallow depth, to search visually for nearby targets and threats on the surface of the water and in the air. When not in use, a submarine's periscope retracts into the hull.
The submarine interiors were sketched aboard L27 in the summer of 1940. The skipper, looking through the periscope, is Lieutenant RE Campbell.
In a periscope, the light enters through one end of the periscope, reflects off a series of mirrors inside at specific angles, and then exits at the other end. This allows a person to see objects that are not in a direct line of sight above the surface, such as when looking from a submerged submarine.
The basic periscope simply shifts the line of sight, so that you can see around a corner or over a wall. It doesn't necessarily do anything to the image just because it's a periscope. But there's no reason you can't add a telescope or wide-angle viewer to a periscope, or even a zoomer to take you smoothly from a wide-angle to a telephoto, in order to add those functions to the shifted line of sight.
Visible waves, ie, visible light is piped through a periscope.
As a "periscope" is an instrument for seeing above a surface of some kind (usually water) from below it, its use will typically occur in sentences dealing with military, exploration, or scientific subjects. Just one example would be, "The submarine was discovered by the scout plane through a fortuitous accident: the sunlight flashed off the glass lens of its raised periscope, revealing its location below the surface."
Prisms are used in telescopes to correct and enhance the image quality by reducing optical aberrations and improving the clarity and sharpness of the image. They can also be used to flip the image orientation so that it appears right-side up when viewed through the telescope. Additionally, prisms can help to increase the focal length of the telescope, allowing for higher magnification of distant objects.