when I saw with the eyefinder nothing was wrong, but the results were half black. view from liveview and record video is the same, half black. When i see image in computer is same
A DSLR has a viewfinder that receives light from the lens (usually projected on a ground glass plane so that you get a projection instead of 3D image). This light arrives in the viewfinder via a mirror. When you take a photograph, the mirror is moved aside and the light instead hits the sensor.
It would appear that your mirror no longer moves completely out of the way and gets stuck. Since the mirror needs to move fast and often, this is one of the most frequent causes of an SLR (not just digital ones) to fail after a long and/or arduous lifetime or when having been assembled less than flawlessly.
Either a stuck mirror or a stuck shutter.
Remove the lens and use the camera menus to navigate to the setup for manual sensor cleanup, which should lift up the mirror fully and open the shutter fully. You'll quickly sees which one is stuck (unless that maneuver fixes something...).
In any case the camera likely requires service.
Which camera are you using? If it's an DSLR (i.e. not a "mirrorless camera"), then the picture you see through the viewfinder is not affected by the shutter speed or aperture settings (unless a preview mode is enabled) and will appear as bright as the ambient light.
On the other hand, the live view and video are affected at least by the aperture setting (aka f-stop range) and if it is too small (e.g. f16, f32), then not enough light gets through the lens and the picture is exposed too dark. Try changing the aperture to the largest possible (e.g. f1.4, f2) and see if that helps.