mattheww50
Flashlight Enthusiast
In my experience from digitizing almost 10,000 Kodachrome® 35mm slides, I think the resolution is a little better than 6 megapixels, but not much. Definitely less than 8 megapixels. That's the point at which the pixel size pretty much matches up to the grain size in Kodachrome I/II/25. While 8 megapixels in the Iphone® sounds great, the reality is the optical system limits the useful resolution to something considerably less than 8 megapixels. You can calculate the Dawes diffraction limit from the diameter of the lens, and because of physical constraints on the size of image sensor and the size of the optical system, it is very difficult to get the resolution above about 5 megapixels. The Pixel size is smaller than the diffraction limit, so you end up resolution considerably smaller that the number of pixels would indicate. By contrast the Sony RX100 has a very large sensor for a point and shoot , and in fact the pixel size in the sensor is about 3 times the area of a pixel the typical phone and low to mid range point in shoot camera. You can apply the Dawes diffraction limit to the Sony's optical system, and it really can delivery a 20 megapixel image in many circumstances. the larger sensor also tends to improve the signal to noise ratio in the images, which has a profound effect in very low light situations. The difference is further impacted by the relatively high powered DSP in the Sony that among other things is able to correct for certain types of optical aberrations in the optical system.There's some validity to that; it's been estimated before that your typical film SLR camera with store-shelf Kodachrome film was good for an equivalent 6 megapixels of detail. The 8 megapixels of the iPhone camera can in some ways compare to that in some situations, and you can even download free apps that allow you to do manual settings (what there is to control, there's no aperture to adjust for example.) The camera phone is definitely the best deal going for anyone who wants full-auto point-and-click photography, but once you start getting concerned about "limitations", it's time to invest in something more serious.
For almost 20 years now when I've gone shopping for a camera, my criteria is to get as close to the professional SLR feature set as possible in a compact format; the Sony RX was the natural choice this time around, and it's really paid off, this camera has actually made me a better photographer..
It is kind of like the difference between the GPS chip in many smart phones (it works, but you don't need, and aren't likely to get 2-3 meter accuracy), and a dedicated GPS device which with WAAS often can achieve 2-3 meter accuracy.