I've been using digital cameras since the first wave of them was introduced in the 90's. Since the start I was making hot pixel maps and that helped fix images

I've been using digital cameras since the first wave of them was introduced in the 90's. Since the start I was making hot pixel maps and that helped fix images using them as a mask in photoshop to reverse the errors caused by hot pixels and non-random noise. A hot pixel map is simply a long-exposure photo taken that is completely black - with the lens cap on, or the lens otherwise blocked from all light. I've found that as the sensor ages, the "hot" pixels get "hotter". I take a new pixel map every six months to a year, and have observed the increase in non-random noise.