Is it normal to see trails in front of dark background?
Whenever I'm in bright light standing in front of a dark place, and I focus on the background in the dark place. Whenever I slowly move my arm up, I could see a ghost image about 1 second behind it before merging again. It WILL NOT happen if I move it quick.
I understand that if I play with my cellphone light in the dark, there will be trails too (I know this is normal as far as I know). Just like how sparklers work.
I don't experience the trails in a bright place or in the day. I also dont see trails behind moving cars or stuff like that. All I see is a blurry image, no trails.
Is this normal?