I am trying to take two identical pictures that are exactly the same in every way except for noise. However, I am finding it incredibly difficult due to the tiny angular movements that seem to always happen between shots on both my DSLR and mobile phone. I know about shutter shock and the vibrations that come from a moving mirror, but my phone has no moving parts (as far as I know). So, why is it that if I take two pictures in quick succession, using a remote so that my hands don't touch the phone, and using a tripod, I observe a minute pixel-size translations between images taken in immediate succession? (It also happens with my DSLR, but that's easier to explain because of its mechanical vibrations.)
Explanations I have thought of are,
- My tripod is settling due to gravity and latent tension after moving it.
- Some kind of internal image stabilization that I can't turn off is translating the shots differently every time.
Why do you think my images are coming out slightly different? Is taking two completely identical photos a fool's errand or is there a way to get it done?