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129

TL:DR Do primary colors really exist in the real world? No. There are no primary colors of light, in fact there is no color intrinsic in light at all (or any other wavelength of electromagnetic radiation). There are only colors in the perception of certain wavelengths of EMR by our eye/brain systems. Or did we select red, green, and blue because those are ...


50

This is called a color cast. As others have said, it is a result of an incorrect white-balance. Your camera is assuming that light is of a different color than it is and is compensating for that, resulting in a color cast. It can happen with any camera. Some Automatic White-Balance systems are better than others. A long time ago, some cameras had dedicated ...


46

The goal of the imaging engineer has always been to capture with the camera a faithful image of the outside world and present that image in such a way that the observer sees true to life picture. This goal has never been achieved. In fact the best images made today are frail. If this goal were to be achieved, you would need sunglasses to comfortably view an ...


42

If your goal is to practice composition and work with shadows and lighting cheaply and efficiently, then you should shoot digital, not film. You will get more immediate results, and the ability to make changes at the time of shooting. As far as color vs. B/W is concerned, you can make changes in post with color filtering to understand how different color ...


39

Is this an effect like HDR or plain photoshop (post processing)? I'd say neither. The effect is natural. The ships' propellors churn the water quite a bit, causing the wake to become aerated. This is obvious from the white caps on the surface. But the aeration also extends below the surface. Aerated water like that tends to appear lighter shades of blue and ...


38

but why i can see little bit of orange color with shutter speed 1/400 ? My best guess is that you had the camera set to automatic white balance (AWB). In the 1/200s shot, the moon was bright enough to easily be the brightest thing in the frame, and the white balance algorithm decided that that object was most likely to be white. In the 1/400s shot the ...


35

It is related to a heated substance, albeit in a somewhat theoretical way. The substance is an ideal incandescent black body, which would radiate a given color within a given color space at a given temperature. The location within the color space vs. temperature is called the Planckian locus, and I don't claim to understand everything in that article, but ...


35

You said, this is the information that is captured at first by digital cameras. That is not correct. By themselves, sensors on most digital cameras respond to a broad band of frequencies of light, beyond what humans can see into the infrared and ultraviolet spectrum. Because sensors capture such a broad spectrum of light, they are terrible discriminators ...


33

Why don't cameras offer more than 3 colour channels? It costs more to produce (producing more than one kind of anything costs more) and gives next to no (marketable) advantages over Bayer CFA. (Or do they?) They did. Several cameras including retailed ones had RGBW (RGB+White) RGBE (RGB+Emerald), CYGM (Cyan Yellow Green Magenta) or CYYM (Cyan Yellow ...


33

"Better image quality." You use that phrase. When we say image quality in reference to comparing two lenses, we rarely are talking about anything with regard to which one is "... less dark and gives more vivid colors."¹ Those things are more a function of the light in the scene, the photographer's skill at seeing that light and capturing it while also ...


27

Wikipedia's introductory statement on color temperature relates them quite well: The color temperature of a light source is the temperature of an ideal black-body radiator that radiates light of comparable hue to that of the light source. Black body radiators are an idealized concept, that radiate an energy spectrum with a peak intensity at a frequency ...


26

We ended up with RGB because they're a reasonable match to the way the three types of cones in our eyes work. But there's no particularly privileged set of wavelength choices for Red, Green, and Blue. As long as you pick wavelengths that are a good fit for one set of cones each, you can mix them to create a wide range of colours. The way colours are ...


25

I think "several fluorescent fixtures that I use to light my studio" is the key here. I'm guessing that the very high ISOs are accompanied by very short shutter speeds. Fluorescent lights cycle, and there are color variations within the cycle. Repeat your test with incandescent light or sunlight (or a strobe with high-speed sync). See Do fluorescent ...


25

What is going on? I compared both pictures of the field (left out the one with the tractor, as it suffers from the same problem as the other over-exposed picture, IMHO) in After effects. The image above is a composition of all that I did: First, the composition of both your original images that I made in AE (white canvas added only here), then both ...


23

Many navy ships intentionally inject air into their wake to obfuscate their sonar signature. See Prairie-Masker air system This added air gives the wake a light blue hue, and since the air bubbles are small they persist for quite some time. I served on a US Navy ship and can attest that the color in this photo accurately depicts what our wake looked like.


22

First, a little background to clear up a slight misunderstanding on your part. The vast majority of color digital cameras have a Bayer filter that masks each pixel with a color filter: Red, Green, or Blue.¹ The RAW data does not include any color information, but only a luminance value for each pixel. However, RGB filters necessarily cut out two thirds of ...


22

sRGB is a color-space developed by HP and Microsoft in 1996. CRT monitors were common and therefore sRGB was based on the characteristics of these monitors' capabilities. A good write-up of the history and reasons can be found here. The chromaticity coordinates and available colors were chosen on what the phosphors used in CRTs could produce back then. ...


22

More than a comment, less than an answer, because I have no clue what camera/lens/film... The car's registration plate sets it firmly between August 77 & July 78 - the letter is the year for old UK plates S=77 Ref: http://www.theaa.com/car-buying/number-plates There's prestige in having a 'new' plate, so there's a high probability this was even shot ...


21

Well, in order to get good results, you'll have to make the plunge into non-auto settings. I'd recommend Manual mode. The problem you're running into here is that you are pointing your camera at a bird in the sky, which is bright. Camera meters are set up to try and make every exposure a uniform grey in terms of brightness. So if you point your camera at ...


20

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 ...


19

Yes, if you shoot RAW. If you have difficulty visualizing an image in B&W, shooting in B&W gives you a good approximation of the final image at the time of shooting so you can adjust; many digital cameras can even process B&W with color filters, so if you have a particular type of processing in mind, such as using a red filter to darken skies (...


18

What you are seeing is Infra-Red (AKA 'IR') The sensor (probably) has an IR filter, but strong sources such as fire can still get through, and show up as a light purple on most CCD / CMOS sensors.


18

I can tell 3 common reasons for weird/fake colors in astrophotography: Chromatic aberration makes some starts appear white in the center, but their borders blue or red, depending what of those two are out of focus. Demosaicing algorithms tends to fail for bright white objects against a dark background, and you see red or blue in one border of some stars. ...


17

My monitor is calibrated (less than a month ago). I see the white/gold dress, but the highlights on the white piping have a blue tinge to me. However I have seen pics of the (supposedly) original dress, and it is a deep blue and black. To me, the only way I can reconcile this pic, and the pic of the actual dress is that if this pic was taken with a really ...


17

If this image were RAW, the color would still be there. But since it is JPEG, I'm afraid not. The fact that the image is in RGB format does not help, because I'd you look, you will find that in fact for each pixel, each of these values is set to the same thing: (0,0,0), (37,37,37), (221,221,221), or whatever. That is, they're all gray levels, just ...


17

The colour temperature is related to the black-body radiation produced by hot objects. The black-body radiation curve, shown below, shows the approximate intensity* curves at each wavelength for the radiation emitted by bodies at 5000K, 4000K and 3000K. * It actually shows the spectral radiance curve, which is a kind of flux. But you can think of it as an ...


16

How can this be explained technically? Auto Exposure and Auto White Balance. The camera is trying to expose the image properly, but there's a huge difference in brightness between the shaded areas (most of the scene) and the foreground that's lit by strong direct sun. In order to get most of the image exposed correctly, it has to overexpose the car door ...


16

How can I make my shots look like this one? I added an emphasis to the question you asked, which is pretty much the answer: You make an image like that. There's no way your camera will produce an image like that directly. No matter what settings you dial in. You have to apply some heavy post processing to get an image like that, the steps are usually: The ...


16

A few notes from this long-time optical systems engineer. First, there are things called "hyperspectral" cameras which use gratings or equivalent to break the incoming light into dozens or even a couple hundred color(wavelength) channels. These as you might imagine are not used, or useful, for producing color photos per se, but are great for distinguishing ...


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