Using an a6000, I've been learning a lot about photography and how to control the depth of field (by changing the aperture), blurriness (by changing the shutter speed), and the noise floor/light sensitivity (by changing the ISO). However, when shooting at night, or really in any dark place, it gets harder to get the right, or at least usable exposure.
Assuming that I change any of the above three parameters(Aperture, Shutter Speed and ISO), and it won't impact the final image I want, which one of these parameters has the least impact on the final image? Another way to put it, which one of the three parameters is easiest to recover/fix in post-processing or does that depend on the image itself?
I realized that using flash IS an option in some cases, but not in all cases.