{"id":2974,"date":"2013-06-21T13:43:52","date_gmt":"2013-06-21T21:43:52","guid":{"rendered":"http:\/\/ralphnordstromphotography.com\/wordpress\/?p=2974"},"modified":"2019-11-29T14:38:28","modified_gmt":"2019-11-29T22:38:28","slug":"color-management-simple-camera-computer","status":"publish","type":"post","link":"https:\/\/ralphnordstromphotography.com\/wordpress\/2013\/06\/21\/color-management-simple-camera-computer\/","title":{"rendered":"Color Management Made Simple – From Camera to Computer"},"content":{"rendered":"

If Color Space <\/strong>can be described as a box of Crayons as we suggested in\u00a0 Color Management Made Simple – Color Space<\/a>,\u00a0 what else do we need to know about Color Management<\/strong>?\u00a0 Well, Color Management is essentially about getting the right colors – and here\u2019s the most important word – consistently<\/strong>.<\/p>\n

Let\u2019s spend a few moments talking about the \u2018right color.\u2019\u00a0 (I\u2019m inclined to add, \u2018whatever that is.\u2019)\u00a0 The story begins when you press the shutter.\u00a0 Let\u2019s suppose you are photographing the beautiful redwoods of Northern California.<\/p>\n

\"redwoods_130528__SM36093_4_5_6_7-Edit\"<\/a><\/p>\n

The scene is full of rich browns and oranges and vibrant greens.\u00a0 We can say that these are the right colors, these are the colors you want.\u00a0 You set up your camera and snap a picture and your sensor captures these colors, pretty much just as they are (the sensor is playing with pretty much the full big box of 120 Crayons). The camera\u2019s processor does its thing and the image is saved in a file to your memory card.\u00a0 Eventually we\u2019re going to view the photograph on our computer\u2019s monitor and we just might be a bit disappointed.<\/p>\n

<\/p>\n

This is the point where we should mention white balance<\/strong>.\u00a0 Not only do the things we photograph come in different colors, so does the light.\u00a0 And that affects the colors of the things we photograph.\u00a0 For example, a leaf looks different when illuminated by the blood-red rays of a setting sun then it does by that same sun at high noon.\u00a0 That\u2019s usually fine but sometimes it\u2019s not.\u00a0 The purpose of white balance, then, is to compensate for the color of the light you\u2019re photographing in.\u00a0\u00a0 There are white balance settings like Daylight, Cloudy, Shade, Tungsten light, Florescent light, Custom and Auto.\u00a0 When the white balance is set to match the color of the light it makes everything look like it was photographed on a clear day at high\u00a0 noon; in other words, Daylight.<\/p>\n

When I first started photographing with a digital camera the advice I received from those a lot more experienced than I was to set white balance on Auto and forget it.\u00a0 And I did that for many years.\u00a0 But now I set white balance on Daylight about 99% of the time.\u00a0 When I\u2019m photographing during golden hour I don\u2019t want the camera to make that gloriously warm light look like high noon.<\/p>\n

So what effect does white balance have on the photograph we just took. If you are saving your photo files in RAW format, absolutely nothing.\u00a0 White balance setting does not alter the RAW file at all.\u00a0 The only thing that happens is your white balance setting is stored in the EXIF data along with f\/stop, shutter speed and all the other metadata that gets saved.\u00a0 This is great because it gives you complete flexibility in changing the white balance when you get your raw file into Lightroom.\u00a0 But if you save your image files as JPEGs then the image will be altered to apply the color correction.\u00a0 I could talk about white balance for an entire blog post but for this post it\u2019s time to move on.<\/p>\n

So, you composed your shot, set the exposure and focus, snapped the shutter and the file is saved to your memory card.\u00a0 If you saved the image as a RAW file you will have all of the colors that were in the scene.\u00a0 Virtually nothing will be lost.\u00a0 You have the entire Crayola big box, all 120 of them.<\/p>\n

\"crayons_120cnt\"<\/a><\/p>\n

If you feel you need to save your images as JPEGs you\u2019re going to lose some of the colors.\u00a0 But to minimize the loss be sure to save them in the AdobeRGB color space, not the default sRGB.\u00a0 That way you\u2019ll at least get the 96 count Crayon box instead of the 64.<\/p>\n

Now that we\u2019ve returned home (or back to our hotel room), we\u2019re ready to upload the files to our computer.\u00a0 I use Lightroom.\u00a0 And, if you\u2019re like me, you can hardly wait to see them.\u00a0 They looked pretty good on the camera\u2019s LCD when you checked them in the field.\u00a0 But when you see them on your computer\u2019s monitor, well, it can be a bit disappointing.<\/p>\n

You know how you walk into Target and you saunter by the home entertainment department where they have this entire wall wallpapered with TV sets all on the same channel?\u00a0 You can\u2019t help but noticing that the colors are different from one TV set to the next.\u00a0 Shouldn\u2019t they all be the same?\u00a0 Shouldn\u2019t red always be red, not orangish red or brownish red or bluish red?\u00a0 Shouldn\u2019t they just be reddish red?<\/p>\n

They are all receiving exactly the same signal, the signal that says, \u201cDisplay red.\u201d\u00a0 But they all don\u2019t interpret the signal exactly the same way.\u00a0 They\u2019re a lot like a bunch of cats, independent and each doing their own thing.<\/p>\n

Well, our computer displays are no different.\u00a0 They receive a signal that says, \u201cDisplay red,\u201d but they all do it a little differently.\u00a0 It\u2019s one thing if you\u2019re watching \u201cNCIS\u201d and the color of Gibbs\u2019 shirt is a little off.\u00a0 But it\u2019s quite another matter if you\u2019re preparing a photograph and the color of the red rose is off.\u00a0 Not good.<\/p>\n

Fortunately our monitors can be taught.\u00a0 To explain, I\u2019m going to get a little technical here so hang on.\u00a0 (On Mythbusters they\u2019d flash a sign on the screen that said, \u201cScience Warning.\u201d)\u00a0 So here goes.\u00a0 Our digital cameras are really computers.\u00a0 And computers store everything as numbers, and I mean everything.\u00a0 A color is stored as three numbers.\u00a0 The first number is for the amount of red, the second for the amount of green and the third for blue.\u00a0 Let\u2019s say the numbers can range from 0 to 100 (the high number actually gets a lot higher like into the millions but 100 can represent 100% and it makes the conversation easier to follow).\u00a0 If the color is black the three numbers are (0,0,0) and if the color is white the three numbers are (100,100,100).\u00a0 If the color was pure red the numbers would be (100,0,0) meaning that the color only has red with no green or blue at all.\u00a0 A darker red would be (50,0,0), still only red but not as much and no green or blue.\u00a0 Are you with me so far?\u00a0 What would pure green be?\u00a0 It would be (0,100,0) just like pure blue\u00a0 would be (0,0,100).<\/p>\n

Ok, so here\u2019s where color management comes into the picture.\u00a0 Let\u2019s say that we took a picture of a gray card and the camera captured it pretty faithfully.\u00a0 The numbers the camera saves in the image file for the gray are (50,50,50)\u00a0 But let\u2019s say that our computer display tends to make everything a little redder.\u00a0 So if we said to the monitor, \u201cDisplay (50,50,50),\u201d we wouldn\u2019t get a pure gray but a slightly reddish gray.\u00a0 So if we want to accurately display the colors our camera captured we have to cheat a little and change the numbers we send to the display so that it displays the same gray.\u00a0 Since it makes things redder, we need to trick it by telling it to display less read, something like (48,50,50).\u00a0 We need to change the numbers to make the color slightly cyan (the opposite of red) so that when the monitor makes it more red, the end result will be the same gray as the one we photographed.<\/p>\n

Color Management<\/strong>, then, is about changing the numbers that produce a certain color on one device to another set of numbers that will render the exact same color on a different device.\u00a0 This is because all devices have their own built in color biases.<\/p>\n

But how do we know how to change the numbers for our display?\u00a0 Well, actually, we don\u2019t.\u00a0 To do that we need to calibrate our monitor.<\/strong><\/p>\n

\"colormunki\"<\/a><\/p>\n

This is a picture of a Colormunki in action.\u00a0 The device hanging on the front of the monitor measures the amount and color of the light displayed on the monitor.\u00a0 A calibration program flashes different shades of red, green, blue and gray on the monitor and the Colormunki tells the program what it senses which compares it to what it actually displayed.\u00a0 Then it determines the difference and from that it knows what adjustments need to be made so that the monitor display the intended color.\u00a0 It\u2019s a kind of mapping; if it gets one color (three numbers), it changes them to three different numbers but the color is the same.<\/p>\n

This mapping is called a color profile <\/strong>which is saved in an ICM file<\/strong> on Windows machines.\u00a0 You don\u2019t have to worry about where to put this ICM file or tell Windows to use it.\u00a0 The calibration software does all that.\u00a0 And Windows uses this ICM file to adjust the numbers for everything it displays on the screen not just your photographs.\u00a0 And the result you get is true, accurate colors, the same colors you saw in that redwood grove.<\/p>\n

Let\u2019s recap.\u00a0 In the field your digital camera will do an excellent job of capturing virtually all the colors that are there, as long as you save your images as RAW files.\u00a0 For white balance I recommend Daylight although it doesn\u2019t have any affect on the image data.\u00a0 Then, to get those same colors on your computer\u2019s monitor you first need to calibrate<\/strong> it.\u00a0 Using a calibration tool like the Colormunki is the preferred way because it\u2019s the most accurate.\u00a0 But there are programs that allow you to do this manually.\u00a0 Whatever method you choose, a color profile <\/strong>is created in an ICM file<\/strong> that gets saved on your hard drive and Windows uses it to adjust the colors on everything it displays on your monitor.\u00a0 (The MAC has a similar system although I\u2019m not familiar with the details.)\u00a0 Here\u2019s a picture that illustrate the example of the gray card above.<\/p>\n

\"color_management\"<\/a><\/p>\n

And here\u2019s a pretty good post from PC Magazine on calibrating your monitor using software.<\/p>\n

How to Calibrate Your Monitor<\/a><\/p>\n

Two companies that market monitor calibration hardware and software are<\/p>\n