Serene Life

by garik

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19

When discussing the number of colors perceptible to the human eye, I tend to refer to the 2.4 million colors of the CIE 1931 XYZ color space. It is a fairly solid, scientifically founded number, although I do admit it may be limited in context. I think it may be possible for the human eye to be sensitive to 10-100 million distinct "colors" when referring to ...


13

It makes some measurable difference but does not tell the whole story. DxOMark's portrait score is a technical assessment of the output of various cameras specifically in terms of color depth, which they carefully describe as having a "correlation" with color sensitivity, which is the actual nuance in color. If you look at the results of that metric, you ...


11

More bits usually doesn't mean more range, but more precision. That is to say, the ends of the scales, the blackest blacks and whitest whites, will stay where they are (at 0 and the max value) but the number of values between them will be greater with more bits. You quickly fall into diminishing returns here as there simply is no need for that much ...


10

Cambridge in Colour has a very good article on this. If the sensor has a linear A/D converter, the bit depth would cap dynamic range at at 14 EVs as a theoretical limit. However, if it is non-linear, then the bit depth doesn't necessarily correlate. From that, I think we can determine that the sensor in the K-5 doesn't have a linear A/D converter. I can ...


10

Bit depth and color space are not the same thing, and neither are they mutually exclusive. They are different things that exist simultaneously. For a particularly simple explanation: Bit depth determines the fineness with which each distinct color is graded. Color space determines the extent within which those colors are distributed. Let's take sRGB and ...


9

The photosites of a digital sensor are actually analog devices. They don't really have a bit depth at all. However, in order to form a digital image, an analog-to-digital converter (A/D converter) samples the analog signal at a given bit depth. This is normally advertised in the specs of a camera — for example, the Nikon D300 has a 14-bit A/D converter. But ...


9

Basically, life color information is like a box of chocolates crayons... Color information is stored in integers, not analog values — there are a discrete, countable number of colors that can be described at a certain bit depth. Think of the color space like a box of crayons of different colors. A color space describes the types of crayons that are ...


6

You probably need to analyze things step-by-step as your question makes little sense. If you shoot RAW, then your card will contain RAW files. They should have an extension other than JPG. You should be able to confirm this simply by browsing to your card using the operating system file manager. If you see a RAW file (.CRW, .CR2, etc) than you have a RAW ...


6

Most sensor chips only record one color component per pixel, so one pixel can contain for example 14 bits of data for green intensity. The pixels are laid out in a grid where 50% of the pixels record green data, 25% red and 25% blue: RGRGRGRGRGRGRGR GBGBGBGBGBGBGBG RGRGRGRGRGRGRGR GBGBGBGBGBGBGBG RGRGRGRGRGRGRGR When this data is converted to RGB, two ...


5

For all intents and purposes, that would be 8-bits per channel or 24-bit per pixels because what you get out from the camera is a JPEG image and that is its limit. The sensor internally is highly likely to have a greater bit-depth, maybe 10 or 12 bits per channel. This is actually needed to produce an 8-bit-per-channel JPEG because sensor output is linear ...


5

Considering that an average monitor has about 6-bit per channel color depth (8 bit minus the dithering), I guess 10-bit is for color proofing/professional DTP/digital cinema. And higher than 8 bit per channel has another challenges: Video card: the video card needs to support color outputs more than 8 bits per channel. Considering that DVI supports only 8 ...


5

How can dynamic-range be larger than sensor bit-depth? Dynamic range is the logarithm of the ratio between the brightest and and the darkest intensities on the linear part of the sensibility curve. There may be other definitions, but in general it is derived from the ratio of two intensities, objective physical properties of the scene. It is a real ...


4

Be careful not to confuse per-pixel bit-depth and per-component bit-depth. The output of digital sensors is almost always between 10 and 14-bit per-component on a linear scale. That would give between 30-bit color (1 billion) and 42-bit (4 trillions) per-pixel. The site DXOMark measures this using a normalized scale (explained in their white-paper) and ...


4

I think there is some confusion related to the differences between 12 and 14 bit RAW when it comes to its impact on the dynamic range. My understanding is that the 14-bit RAW does not expand the dynamic range. It expands neither the highlights nor the shadows. It gives you more gradual information between the darkest and brightest details the sensor can ...


4

Short answer: You are probably confusing the sensor bit depth with the output file bit depth. There are two completely different and mostly unrelated bit depths: There is the bit per pixel of the sensor and the raw file (in your case 14 bits) this does not relate the the color space in any way because those values are before the demosaicing algorthem ...


4

Why do you want to increase colour depth? Colour depth has little to do with how intense, or how vibrant the colours look, only with transitions between similar colours. To put it another way the main consequence of having a low colour depth is the appearance of banding or posterization in smooth colour transitions. Increasing the colour depth on it's own ...


4

You can increase the colour depth at expense of reducing the spatial resolution. I.e. if you downsample the image 50% on each axis, you can get 2 extra bits of colour depth. Is it worth? I doubt it...


3

The D4 is still a 14-bit RAW camera according to Nikon's own specifications page: NEF (RAW): 12 or 14 bit, lossless compressed, compressed or uncompressed So, it cannot capture 16-bit images off the sensor, at best they are still 14-bit. If I understand the page you linked, it sounds like they are saying the Expeed image processor chips are fully ...


3

"150: the number of hues that the eye can discriminate in the spectrum." "1,000,000: the number of colors (combinations of hue, saturation and brightness) that the eye can discriminate under optimal laboratory conditions." From visualexpert.com However, this seems to be a controversial subject.


2

Firstly to be clear, dynamic range has an inverse relationship to noise - low noise (all else equal) leads to a greater dynamic range. Noise comes primarily from the sensor electronics (read noise, dark current noise), from the discrete nature of light (photon/shot noise) and from conversion from analogue to digital (quantisation noise). DXO mark dynamic ...


2

It is likely that the processing for JPEG and whatever digital processing is applied to the raw file is, is done in 16-bit to maintain quality then converted to 14-bit NEF (or 8-bit JPEG). In the end, it's unlikely to need 16 bits to store the raw data as a 14-bit number provides 14 stops of linear latitude (with exponential detail in each stop toward the ...


2

It depends on both the image and how much editing you are planning to do. Let's say you're only going to adjust levels. Then 8-bit JPEG -> 16 bit PSD -> levels adjustment -> 8-bit JPEG Will give identical results to: 8-bit JPEG -> levels adjustment This is because an 8-bit image converted to 16-bit is identical to the 8 bit version (the ...


2

Lets try a simple example. Lets say we have a color space called "rainbow". It contains the colors of a rainbow, so it is made up of red, orange, yellow, green, blue and violet. The color space describes a range of colors that are covered by the gamut. Bit depth on the other hand defines how many distinct colors we can make within that space. If we only ...


1

These are independent things. Color-space represents all possible colors and is a continuous space. Digital devices require a discretization of the space. This means the steps at each they can represent colors that are within the color space. Here is a simple analogy: Thing about the height between two floors as a color-space. That is the space between the ...


1

None of your three choices are the optimum. When expanding a small unsigned binary integer into a larger one, put the original bits in the high bits of the large number, then continue replicating the whole input number into the lower bits until they are filled. For example, suppose you want to expand a 3 bits value into 8 bits, using the full dynamic range ...


1

This is probably not strictly on-topic in Photo.SE. That said, you'll probably want to interpolate. You have the range [0, 7] representable with three bits, and you want to stretch it so that 0 stays 0 but 7 is mapped to 1023 (the maximum value representable with ten bits). Assuming linear interpolation, you can compute the corresponding 10-bit value from a ...



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