Wesley's Tool-Box

Point-and-shoot digital cameras have reached the end of the 'megapixel race' at around 12 megapixels, giving you a photo with the resolution of 4000x3000. One of the reasons for this peak is that the typical image sensors used in this class can produce only around 10 megapixels of actual data at best, and even less with internal post-processing applied. As a result, camera's 'actual' resolution will be far less than 4000x3000, even if the 'output' resolution is that large. Increasing output resolution any higher without better sensors would be no better than doing a digital zoom - bigger picture without more detail.

A smart shopper would therefore avoid blindly following the megapixel number on the spec sheet, and instead check the sensor size as well as the actual sample images posted in independent product reviews. In many professional reviews, an ISO 12233 Test Chart(partly seen above) is used to check the actual resolution of a camera. DPReview has been extensively using it.

So, why am I talking about this 'actual' and 'output' resolution today? I carry a nice compact digital camera - Kodak Z1085 IS - and an excellent smartphone - iPhone 3GS - with me at all times. The image quality is good for the given class, and they have the maximum native output resolution of 3648x2736 (10MP) and 2048x1536 (3MP), respectively. But I suddenly got curious as to what their actual resolution would be. Unfortunately, searching the internet did not come up with any resolution testing - it was time to do a little testing of my own...