Topic: Grainy/Fuzzy Background

So I tried animating with only a black background and zero set. I really like the way it looked (zero flicker is always a win) but the background seemed grainy, like little flickering dots. Does anyone know how to fix it and/or what causes it? Here's a video that shows the grainy-ness (look at the background):   
The clips were animated at 15fps, both at 125 shutter speed and 50 iso and animated using stop motion studio pro on an iphone 7.

Re: Grainy/Fuzzy Background

I used to use stop motion studio on an iphone 7 as well and got shots with grain. Changing the lighting sometimes helped a bit.