This discussion is related to the primary wide angle camera on the back of an iPhone. Not the telephoto lens. Not the front facing camera. Apple has been using the same sized sensor for the previous three generations of the iPhone, that is, the iPhone 6/6+, the iPhone 6S/6S+ and the iPhone 7/7+. They all use a 1/3" sensor but with different pixel sizes. The iPhone 6 had a 8MP with a pixel size of 1.5um and f/2.2 aperture. Also, Apple added OIS to the plus model. This Combination of large pixel size along with OIS allowed the iPhone 6 Plus to take great photos at that time. The low light performance was significantly better than anything that came before it. With the iPhone 6S family, Apple moved to a newer sensor with a resolution of 12MP, but the pixel size came down to 1.22um. The aperture remained the same at f/2.2. While the image quality in good lighting remained about the same, low light image quality took a hit, especially on the smaller model, with no OIS. With the iPhone 7 family apple introduced a larger aperture, at f/1.8 and added OIS to the regular model as well, but left everything else the same. So the resolution remained at 12MP with a pixel size of 1.22um. Apple claimed that the iPhone 7 allowed 50% more light than the iPhone 6S. This was due to the larger aperture and OIS, since the sensor remained the same. The image quality under good lighting conditions remained about the same, but the low light capabilities saw a significant improvement over the 6S. Meanwhile companies like Samsung, Google and LG stepped up their camera game. Samsung started using a larger 1/2.5" sensor with a 1.4um pixel size along with a f/1.7 aperture, and OIS in the S7/S7 edge. This allowed these two phones to leapfrog the iPhone 7/7+ in terms of image quality. The pictures from the S7/Edge were much better than those of the iPhone 7. LG introduced a 16MP sensor with 1.12um pixel size, f/1.8 and OIS. Then came Google with its Pixel/XL with a 12.3MP 1/2.3" sensor with a pixel size of f/1.55um, f/2.0 aperture and no OIS. Despite a smaller aperture and no OIS compared the the iPhone 7, the pixel blows it out of the water in low light. Daylight performance is also significantly better. The iPhone went from being a market leader in camera performance to a laggard, when compared to these phones. But this might change from the iPhone 8 onwards. The new iPhones, 8/8+/X have a new sensor that is larger and faster. Phil Schiller mentioned in the keynote that the cameras on the new iPhones allow 83% more light. This is a huge jump, especially when the aperture size has remained the same at f/1.8. I believe apple has moved to a pixel size of 1.4um from 1.22um in the iPhone 7, though I'm hoping they've increased it to 1.5um. if the pixel size is indeed 1.5um, expect stellar camera performance from all the three models from this year. Even 1.4um will be a significant step up. Combine this with a new custom designed Image Signal Processor and deeper pixels(whatever that means), this year's iPhone might have the best camera out of all phones this year. I was surprised how little time apple gave to the main camera in the keynote. They were busy harping about the portrait lighting feature. Most people think that the difference in camera performance between the iPhone 7 and iPhone 8 is going to be insignificant, but I think otherwise. Your thoughts on this, people.