Does adding a supplemental lens attachment to a phone increase the megapixels it can resolve? I am reading: https://en.wikipedia.org/wiki/Optical_resolution
But am confused if adding a supplemental lens to an imaging system (in this case my phone) would change the amount of information resolved.
The second part of this is question is, does adding a lens change the amount of information you are able to resolve regardless of the physical size of the image you are capturing if the image is filling the entire FOV/corner-to-corner?
-Examples below.
Thanks!
 A: The minimum feature size that a camera can sense is -- more or less -- the larger of the blur spot diameter (do a web search on "Airy ring") and the pixel size.  When the blur spot is around the same size as a pixel things get complicated -- just ignore that.
You cannot change the number of pixels by changing the lens.
The blur spot size of a lensing system is -- ideally -- limited by diffraction.  In a diffraction-limited lens, the size of the blur spot is proportional to the wavelength divided by the lens's F number, and you cannot increase a lens's F-number by adding more lens elements outside.  So if the lens is diffraction limited then you cannot decrease the size of the blur spot.
So far, we're at two strikes.
The only remaining possibility for improvement depends on whether your cell phone lensing system is diffraction limited.  I suspect that most cell phones aren't strictly diffraction limited, but if you did have a cell phone camera that wasn't diffraction limited, then you'd have to make a corrective lens for that specific phone model, and very possibly for each specific phone.  So in theory -- maybe you could make things a bit better.  In practice, it would take less time grind your own lenses to work with a bare imaging chip, and build your own camera -- and even less time to get a part-time job flipping burgers, and buy your own camera.
For the given example -- where you have an 8-1/2 by 11 inch sheet of paper that's filled with QR codes and a microfiche image of that same sheet of paper.  Assuming that the microfiche image is perfect, assuming that you have a perfect microscope, and assuming there's no correction you can apply to the phone's lensing system could get no additional information from the original paper than from the microfiche image.
A: No.  A modern digital camera has a chip that is made up of a grid of tiny photosites that are sensitive to light. Each photosite is usually called a pixel, a contraction of "picture element".
Each part of the image is simply one of these pixels.  Think of it as the resolution of a camera.
Lenses cannot add to the number of the photosites on the chip.
I hope this helps.
A: It does not. But it changes the amount of useful information in each pixel, by changing the "solid angle" from which light enters each pixel.
For example, suppose you're taking a photo of the Moon using a camera with a square sensor with 1000 pixels in each direction --- that's one megapixel. (Yes, that's no longer impressive, but it makes the math easy.)  What usually happens is that you are inspired to take the photo because the Moon looks big and pretty to your eye-and-brain optical system, which includes a half-billion years of accumulated trickery, but in your camera you discover that the Moon's apparent diameter is pretty small.  Maybe it's 10% of the width of the image, or 100x100 pixels.  If you're not interested in the rest of the sky, you've just used your one-megapixel camera to take a 10-kilopixel picture. Inefficient, because 99% of your image is boring.
Now you add an optical lens so that the image of the Moon on the sensor is bigger --- maybe 90% of the width, so that the number of interesting pixels is 900x900 = 810 kilopixels. Your sensor is still going to give you its entire megapixel, but now you're going to ignore far fewer of them.
A: Adding a lens will only zoom the picture, but does not increase the number of pixels used by the camera to store the picture.
The megapixels of camera cannot be changed by the use of a lens.
