How are smart phones able to take good photos with small lenses?

Sorry if this has been covered, I did a search and didn't find the exact answer I was after.  How can a lens so small create photos so nice.  Now I understand there is no comparison to DSLR, but still they are very good.  

Could this be an indication that smaller lenses could be coming for larger cameras?  

I think that the main reason for the size difference in slr vs rangefinder camera lenses is the presence of a mirror in slrs, which prevents the lens from getting as close to the film/sensor plane as required for a particular angle of coverage, given the maximum aperture one wants. Rangefinder lenses, on the other hand, have no problem putting their rear element as close to the sensor plane as required for a true WA lens. Slr WA lenses are actually reverse teles, which require many more elements to correct distortion, and so have to be much longer and heavier than corresponding rangefinder WAs. They also need to have greater light gathering power, and so, for a given aperture, the lens diameter is much larger.

The manufactures design the camera and sensor around the size of lens they are working with.  So they take great photos, but if you want to blow them up to any decent size, that's where things start getting soft.  

Define good.
If you mean good for the size they are meant to be displayed at then it is simple. The lens elements are ground to enable them to produce an adequate image on the plane. It is the simple principles of light physics.
And no this does not mean that lenses for larger cameras will get smaller. They require a certain size, and configuration to produce an acceptable image on the plane.

I doubt it unless said smaller lenses were slow (not F2.8 or faster ) Yes, they are very good when viewed online but when printed or enlarged, the IQ drops off. Plus the small sensor makes it very difficult to isolate your subject by blurring out the background as a "fast" aperture would...

Ryan O wrote: Sorry if this has been covered, I did a search and didn't find the exact answer I was after.  How can a lens so small create photos so nice.  Now I understand there is no comparison to DSLR, but still they are very good.  

Could this be an indication that smaller lenses could be coming for larger cameras?  

Wouldn't count on smaller lenses any time soon. The science behind a SLR camera lens is very precise and well tuned – they're the size that they are for a reason.

Read above for a possible explanation.

John Landolfi wrote: I think that the main reason for the size difference in slr vs rangefinder camera lenses is the presence of a mirror in slrs, which prevents the lens from getting as close to the film/sensor plane as required for a particular angle of coverage, given the maximum aperture one wants. Rangefinder lenses, on the other hand, have no problem putting their rear element as close to the sensor plane as required for a true WA lens. Slr WA lenses are actually reverse teles, which require many more elements to correct distortion, and so have to be much longer and heavier than corresponding rangefinder WAs. They also need to have greater light gathering power, and so, for a given aperture, the lens diameter is much larger.

John Landolfi wrote: I think that the main reason for the size difference in slr vs rangefinder camera lenses is the presence of a mirror in slrs, which prevents the lens from getting as close to the film/sensor plane as required for a particular angle of coverage, given the maximum aperture one wants. Rangefinder lenses, on the other hand, have no problem putting their rear element as close to the sensor plane as required for a true WA lens. Slr WA lenses are actually reverse teles, which require many more elements to correct distortion, and so have to be much longer and heavier than corresponding rangefinder WAs. They also need to have greater light gathering power, and so, for a given aperture, the lens diameter is much larger.

  they are only getting better.