Hi, I'm just trying to understand the physics of an ND filter, personally I do own a ND4 for my 18-55mm which I really bought just to mess around (The filter of course, not the lens).
I understand that a ND filter is supposed to reduce the incoming wavelengths of light reaching the sensor equally. However is not the purpose of a narrow high number aperture supposed to also perform the same task just with blades instead? Of course I understand that aperture cant perform the same amount of light reduction that a high ND filter such as a ND400 filter can achieve. So really my question is, are low ND filters worth it since it seems most dslr apertures can actually duplicate the reduction capabilities of low ND filters?