The Null Device
Posts matching tags 'popular delusions'
In an attempt to combat the more-megapixels-is-better delusion, the popular camera review site Digital Photography Review has added a new statistic to its camera specification databases: pixel density:
Pixel Density is a calculation of the number of pixels on a sensor, divided by the imaging area of that sensor. It can be used to understand how closely packed a sensor is and helps when comparing two cameras with different sensor sizes or numbers of photosites (pixels). Because the light collecting area and efficiency of each photosite will vary between technologies and manufacturers, Pixel Density should not be used as an absolute metric for camera quality but instead to get an impression for how tightly packed the imaging chip is.Tellingly, looking at the specs of the compact cameras I've owned, pixel density is one thing that's only getting worse. My current compact, a Canon PowerShot A570IS, clocks in at 29 MP/cm2, considerably behind its predecessor, a PowerShot A620 (19MP/cm2). Though it still does better than its immediate successor (with 32), and even Canon's high-end compact, the PowerShot G9, gets a marginally better 28. In contrast, my venerable old four-megapixel PowerShot G2 got 10 MP/cm2—which is almost in the DSLR ballpark—and it showed in the dynamic range and colour reproduction. Granted, it didn't fit into a pocket (unless one was wearing a large overcoat), but the photos did look good...
Hopefully the megapixel race-to-the-bottom will soon end as the public becomes aware of the fact that there is such a thing as pixel density and that it affects photo quality. Then maybe we'll see a new crop of 6-megapixel compacts, and a public that's aware that they actually take better pictures than higher-density ones.
Best picture quality with 6 megapixel!, or an assertion that, as the number of pixels in a compact camera increases beyond 6 million, the image quality decreases; the finer pixels have lower sensitivity and dynamic range, and thus are more susceptible to noise, while suppressing the noise algorithmically results in loss of actual picture resolution. Of course, the clueless masses, who don't like to think about these things, have been conditioned to equate higher numbers of megapixels with better quality, and will thus happily shell out more money for cameras with poorer image quality and the assurance that they are actually better because the files they produce are bigger.