To match our lenses how much sensor resolution do we need?

I hope my question makes sense - How much resolution would our sensors need to have in order to trump our lenses?  There was a great blog post I read some time ago on this subject.  It wasn't exactly clear what the answer was and I was looking to find the answer. 

If I recall there was a crazy formula that went along with solving the answer. 

How big is a light particle?

Or, infinite?

Would the light particle size even matter seeing that that lens and sensor would need to respond to either way? 

Not even a clue on this one, but intriguing question.  I'll be following this one. 

Carlos wrote: Would the light particle size even matter seeing that that lens and sensor would need to respond to either way? 

The lens is irrelevant if we presume that is doesn't significantly affect the quality of the image. Any sensor element that is larger than a light particle is going to introduce aliasing (maybe half a particle?... not really sure how the Nyquist theorem folds into this).  I'm just saying that when resolution of the receiving end is smaller than that of the source material, you lose data. Therefore, for a perfect lens you need an infinite sensor.

In the real world it's still going to be awfully high resolution.

garyrhook wrote:

Carlos wrote: Would the light particle size even matter seeing that that lens and sensor would need to respond to either way? 

The lens is irrelevant if we presume that is doesn't significantly affect the quality of the image. Any sensor element that is larger than a light particle is going to introduce aliasing (maybe half a particle?... not really sure how the Nyquist theorem folds into this).  I'm just saying that when resolution of the receiving end is smaller than that of the source material, you lose data. Therefore, for a perfect lens you need an infinite sensor.

In the real world it's still going to be awfully high resolution.

 

On some of the cameras, mainly medium format, the lenses, or legacy lenses do limit the IQ. For example the Pentax 645D showed that their legacy lenses, which were fine with film, could not resolve well enough for the sensor. So the had to make improved versions of them, at a much higher cost. Light particles have nothing to do with optics. The particles travel in a wave front of 1 micron, or 1 millionth of a millimeter. The glass has to allow a certain amount of the light through without reflecting back part of that front. A perfect optical element is at a 1/100th wave, or none of the wave is wasted. But most camera optics are somewhere between a 1/2 to 1/4 wave. A 1/4 wave is the minimum for an astronomical optic, or a quality optic, less is better. The wave front measurement is how you determine how deep the pits are in the glass, from the smooth surfaces. The pits interrupt the front throwing the different color waves out of the light, or part of the light away. This all affects how well the image is formed on the sensor, or how cleanly. The sensors can resolve a lot more than they are, but it will take a lot of work to get there.
With the sensors going higher all the time, there will be a point where, and I think we are there already, that the lenses are the limiter. For the manufacturers the work to get lenses from where they are now to a common wave standard will be a lot of work, and expensive. This is because for now machines cannot polish, and figure an optical element to the same level as a person can by hand. This is also why their lenses are all over the place wave front wise. This may change eventually, but no machine has the touch to do it. Also that standard has to be achieved on two surfaces for each element, so you are dealing in a 6 element lens with 12 surfaces. That is a nightmare thought to me. To put it into perspective the deepest pit on the glass would be in the 100,000th to 1 millionth of an inch to achieve a 1/4 wave front.