Glad to hear the light coming in from the left is just what gets around the lens cap. I think lens caps are just for protecting the lens, and don't promise to achieve total darkness for experiments or whatever else.   As to bad pixels, well, I don't know. I kind of ignore the issue and hope the camera is managing to hide them from me, as otherwise it's just going to make me mad not being able to fix them. I'd be interested to hear how expensive it is to "fix" them (meaning replace the sensor). Also, I think of them as something that only happens during sensor manufacture, but I wonder if there's anything the user does that influences having more or fewer of them.

I also get none of the problems you experience. You should get your camera checked out.

thanks, you're right there's a light leaking through the lens cap, glad it does not have any defects though it bothers me on how hot pixels appear a lot during shooting in low light or just popped out whenever there's a dark background do you think it already got dead pixels? i tried pixel mapping and sensor cleaning still it appears, i already maxed out the single pixel slider in C1 still i need to manually cover it every single one, and i know hot/pixels are very common but i think mine is too much

Any chance light could be leaking around your lens cap? What if you repeat this test, but holding your camera under dark towels or coats or something, and maybe with the room light off? Not sure your sensor isn't damaged, but I'm having a hard time imagining sensor damage that would look like THAT.

Assuming still photography of a general nature; Aperture priority, set aperture to F8 or F5.6 ISO set to Auto ISO, range base to 6400, minimum shutter speed 1/100 sec Viewfinder screen set to show picture effect/exposure, histogram, blinking highlights and exposure information Focus set to AF-S with single point or area with 9 points Go out, make photos, see what's working and what's not, adjust to your own liking and use case.