Mean a very, very, long, long time.
Shameful, you should have learnt about them at the kindergarten level of Federation School. How did you pass the Galactic exams without knowing this fundamental stuff?
In case you're wondering, LOL!
I know that some of our nice cousins over the water sometimes get us seriously wrong. Our fault for expecting too much of them...whoops, I'm outa here!
German, 35mm, rangefinder camera designed and manufactured by Leitz Wetzlar in 1952.
The IF was fitted with Elmar 50mm f/3.5 general purpose lens and a focal plane shutter with cloth curtains.
Shutter speeds ranged from 1/25 to 1/1000th of a second.
One of my photos shows the camera serial number,a very important clue in identifying which model it is.There has been more written about Leica cameras,including serial number lists,than almost any other camera brand.