Stay Under 7 Megapixels To Avoid Photo Noise And Diffraction

We've mentioned the arbitrary nature of the megapixel war before, but only in general analogies. Ross at the Petravoxel blog gets precise and provides proof on why going over 7 megapixels in a point-and-shoot makes absolutely no sense.

To try and sum up Ross's reasoned and technical argument against camera companies shoving more and more megapixels down the buying public's throats, it's about what happens when you make pixels teensy-weensy in an effort to cram a (nominal) 12 million of them into one exposure. When light is captured in pixels at microscopic sizes, it's focused not in a sharp pinpoint of clarity, but a fuzzy bulls-eye pattern, named the "Airy disk" and showing up all over your photo.

Camera manufacturers aren't blind to this, but their efforts to fix it, in models such as the Olympus FE-26, often backfire:

The FE-26 is a "12 megapixel" model (actually it's more like 11.8 Mp) using a 1/2.33″ sensor. This means each pixel is about 1.5 microns wide. When pixels are that small, the random difference in photon counts between adjacent pixels can add quite a bit of noise to the image. To solve this, the camera's processor chip applies a noise-suppressing algorithm, which unfortunately smears out all the fine detail and texture in the scene.

Read Ross's post and its backlinks for a more mathematical and photo-minded take on "The Great Megapixel Swindle", and walk away with the knowledge that, though your four-year-old digital camera may seem outdated, trading up may actually hurt your ability to capture crisp images.

The Great Megapixel Swindle: An Example [Petavoxel via Consumerist]


Comments

    Surely this could be a wakeup call to manufacturers that they could sweep the boards with the tech minded if they could have one or 2 cameras in their range that met the needs of said techheads?
    Decent optics and optical zoom (no digital zoom feature at all), accurate viewfinder, HD Video, nice Macro mode, low noise and high sensitivity 6mp sensor.. slo-mo video would be nice, as would rapid-fire and a user hackable OS!! (now I'm starting to ask for too much)
    But seriously, how hard can it be?
    Such a camera would get rave reviews from camera review sites if it all worked properly.

      StevoTheDevo,

      Sam below gives you the answer to that: DSLR's.

    I think it's time for the megapixel war to be over, and the ISO war to start!

    Personally I have a 12 Megapixel dSLR (APS-C size), and TBH, I don't really need any more (I can understand full frame wanting more though - especially birders).

    These days with P&S cameras, having more megapixels really only means that each photo is going to take up more space on the card as you're going to have to downsample to get the quality back anyway.

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