What to Fight Over After Megapixels?

NewScientist has a quick look at where the digital image crowd is headed now that the megapixel wars are drawing to a close. Looks like an emphasis on low-light performance and color accuracy in addition to fun software tools are the new hotness. "For years, consumers have been sold digital cameras largely on the basis of one number - the megapixels crammed onto its image sensor. But recently an industry bigwig admitted that squeezing in ever more resolution has become meaningless. Akira Watanabe, head of Olympus' SLR planning department, said that 12 megapixels is plenty for most photography purposes and that his company will henceforth be focusing on improving color accuracy and low-light performance."

Comments

Re:HDR? Depth channel? Optical SVG?

[morgan_greywolf]

Optical SVG - the ultimate! Forget pixels. Have cameras sketch accurate SVGs of a scene with the ability to show or print at any resolution.

Good luck with that one. It's a lot harder than it sounds. Try tracing a simple 2-color bitmap in Inkscape sometime and zoom in real close. Now try tracing a full-color, full page photograph in the maximum number of colors possible.

Oh, BTW, hope you got lots of RAM and time to wait....

Re:Low Light

[hankwang]

The performance at low light is ultimately limited by fundamental physics. If you want to take a picture of a scene with brightness L (cd/m2), exposure time t, aperture numebr N, the amount of light reaching the sensor is H = L t /N^2. For example, at 5 cd/m2 (twilight?) and t=0.03 s, N=2.0, we find H = 0.04 lux seconds at the sensor.

That is about 10^16 photons per square meter. Of you cram 10 MP on a 5x5 mm sensor, that is 3000 photons per pixel. Each pixel has a color filter that on the average transmits 25% of the photons, which means 750 photons per pixel. Simple Poisson statistics means that you get a noise that is 1/sqrt(3000) = 4% for these numbers. That is if the sensor has 100% effectivity and no electronic noise.

Re:Compression

[Flaggday]

e.g. when I went from a 4 mega pixel camera to an 8 mega pixel camera my file sizes became 4 times larger.

This is normal. When you double the resolution, you double it in 2 dimensions. (Height and Width) This results in a four-fold increase in data size.

But 4 megapixels to 8 megapixels isn't doubling the image size, it's doubling the number of pixels. So it is reasonable to expect the file size to double, not quadruple.