A neutral density (ND) filter is like sunglasses for your lens. And just like with our eyes, wearing an ND filter on your lens directly affects the pupil size - or - the aperture size.
Why does that matter? Well, remember what we learned in Ep 004 (Demystifying the Exposure Triangle) - the wider your aperture (or f-stop), the more light that comes in, and the smaller your focus area (shallow depth of field.)
The smaller your aperture, the less light that comes in... but you now much larger focus area.
Follow along through this video and we'll explore how you can harness the power of an ND filter to shoot a very dynamic shallow depth of field image or scene - in the middle of the bright sunny day, shooting straight toward the sun.