"But at low ISO nothing can beat this camera." - CEO SIGMA

Started 7 months ago | Discussions thread
gaussian blur
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Re: Sigma cameras are for camera heroes.
In reply to Wayne Larmon, 7 months ago

Wayne Larmon wrote:

Only because camera manufacturers have somehow got away with misusing the term "pixel."

No they haven't.

Each pixel on a Bayer sensor only captures a single color

So what? That doesn't mean it's not a pixel.

Technically they should be called sensels, for sensor elements, but the number of sensels is the same as the number of pixels, so the distinction is not particularly important.

They are not combined to form an image with fewer pixels. A 36 megapixel Bayer sensor has 36 million spatial locations sampling 36 million spatially independent samples, resulting in a 36 megapixel image. Each Bayer pixel works with many of its neighbors to produce a full colour pixel and with very high accuracy. Delta-E (how far off the colours actually are) on Bayer is lower than with Foveon.

Bayer favours luminance over chrominance, which is how the human eye works. Having full chroma resolution isn't anything humans can see so there's not a need to capture it at full resolution. That's why you can blur the chroma in Photoshop and not see a difference. Amusingly enough, it's also what the new Foveon Quattro is claiming as one of its advantages.

It is a stretch to call a receptor that can only capture a single color a pixel. When pixels in other devices (monitors) have true R, G, and B pixels (or at least RGB triplets.) Pixels in images are R, G, and B.

It's not a stretch at all, but as I said, technically, it should really be called a sensel, and since the number is the same, it doesn't change anything.

Manufacturers of devices that use Bayer sensors should not have been able to use "pixel" the way that they do. Among other reasons, it leads to overexpectation when looking at 100% crops. On cameras that have Bayer sensors.

Nonsense. The usage is absolutely correct and there doesn't need to even be an image at all to determine the pixel count. It's a physical property of the sensor.

A Nikon D800 with its lens cap on produces 36 megapixel images, just ones that are all black and not particularly interesting. Out of focus images are also a 36 images, just ones that are blurry. An image need not be sharp and well exposed for a pixel to be counted as a pixel. What someone expects when pixel peeping a 100% crop in no way changes the number of pixels on the sensor.

Only Sigma is pushing an alternate definition, and not only have they changed it over the years, but they even contradict themselves in their own marketing literature and with the very patents that detail how it works. That means they're not being honest.

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