NGC 7000, South America nebula in Cygnus, taken by me from NAO Rozhen. 2 shots composed by 45 frames @ 30s, ISO 51200 with SW 200pds and Pentax k-5. Same processing with DeepSky Stacker and LightRoom.
To check the polar alignment of your telescope look trough the polar scope. When turning the Ra axis the polar star should move in the exact circle in the eyepiece without any deviation.
Removing the DSLR build in IR-cut filter will give you at least 50% more sensitivity for hydrogen alpha emissions of the nebulas. Also the camera will be more light sensitive at dark allowing you to shoot more faint objects.
We can check what is like to process day shot with similar to astrophotography techniques. It is cloudy in Bulgaria for the next week or so and I took shots of the nearby mountain trough the fog with 200mm lens.
Most of the modern LED backlight screens including Laptops, TV and smart phones use PAM technique for Pulse-amplitude modulation. This means that they switch on and off state very rapidly.