Konica Minolta AF-2840 Primary RGB and secondary CMY colors, Complementary colors

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AN INTRODUCTION TO COLOR

Primary (RGB) and secondary (CMY) colors

The RGB color model is an additive process that uses the primary colors of light: red, green, and blue. An additive color system mixes the three colors to recreate the entire spectrum of light. If all three colors are mixed, white light is produced. Television sets and computer monitors use RGB to create images.

The CMY color model is a subtractive process that uses the secondary colors: cyan, magenta, and yellow. A subtractive color system recreates color with pigments and dyes to absorb unwant- ed color. If all three colors are mixed, black is produced. Film-based photography is a subtractive process. Printing technology is also a subtractive process, but, unlike photographic systems, it requires a black channel (K). Because of the imperfections of printing inks, cyan, magenta, and yellow cannot produce a true black when mixed, printers use what is called a four-color process (CMYK) to reproduce images.

In photography, red, green, and blue are the primary colors. The secondary colors, cyan, magen- ta, and yellow, are made from combining the primary colors: cyan = blue + green, magenta = blue

+red, and yellow = red + green. The primary and secondary colors are grouped in complemen- tary pairs: red and cyan, green and magenta, and blue and yellow.

Complementary colors

Knowing the complementary colors is very important in color balancing. If the image has a specif- ic color cast, either subtracting the color or adding its complementary color will create a natural looking image.

RED

Decrease the amount of red.

GREEN

Decrease the amount of green.

BLUE

Decrease the amount of blue.

If the image is too…

Increase the amount of red.

CYAN

MAGENTA

Increase the amount of green.

YELLOW

Increase the amount of blue.

Adding or subtracting equal parts of red, green, and blue will have no effect on the color balance. However, it can change the overall image brightness and contrast. Usually, no more than two color channels are needed to color balance an image.

Color balancing is a skill that develops with practice. While the human eye is extremely sensitive in making comparative judgements, it is a poor tool when making absolute measurements of color. Initially, it can be very difficult to distinguish between blue and cyan, and red and magenta. However, adjusting the wrong color channel never improves an image; subtracting blue from an image that is too cyan will give a green cast to the image.

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Contents AV-A209 Tone-curve corrections Selective-color paletteColor Examples Before YOU Begin Table of Contents Page Table of Contents Page For Proper and Safe USE Page Package contents System RequirementsIBM PC/AT compatible computers PolishInstallation Before installing the utility softwareInstalling the utility software Windows Page Installing the utility software Macintosh Page Windows Installing Adobe Photoshop ElementsLaunching the scanner utility from Photoshop Elements MacintoshNames of parts Before scanner setup Connecting the USB cableTurning on the scanner Connecting the AC adapterDisconnecting the scanner Turning off the scannerLoading the film Where is the emulsion?Film formats Handling filmLoading mounted slides Using the FH-U1 and SH-U1 film holders Using the APS Adapter AD-10 sold separatelyLoading a film holder into the scanner Ejecting a film holder Launching the Easy Scan Utility Easy Scan UtilityUsing the Easy Scan Utility Canceling an index scan, prescan, or final scan Macintosh Page Pixel Polish button Auto Dust Brush button File types BMPAdvanced scanning p Dimage Scan Dual III UtilityBasic scanning p Image processing pSelecting the film format and type Launching the DiMAGE Scan Dual III UtilityLaunching the utility from an image-processing application Dimage Scan Dual III Utility Basic ScanningIndex scan Main window and index scan tabCanceling the index scan Making an index scanSelecting index thumbnails Flip and rotate images Fit-to-window button Prescan Main window and prescan tabMagnifying tool Making a prescanGrab tool Auto croppingCHP button APS film Manual croppingPrescanning the cropped area Auto Dust Brush Removing the effect of dust Pixel Polish Correcting images automatically Main window and Pixel Polish tabPage Making the final scan using Jobs Quitting the DiMAGE Scan Dual III Utility Setting scanner preferences Dimage Scan Dual III Utility Advanced ScanningPage Exposure-control tab Saving exposure settings Loading exposure settingsMore index scan functions Reverse frame orderSaving the index images Saving an index fileLoading an index file Autoexposure control More prescan functions AE area selection AE lockFocusing the scanner More prescan functions Point AF AutofocusManual focus Inputting scan settings manually Scan setting windowAbout resolution and output size Scan setting examples Saving scan settings as a Job Deleting a JobCustom Wizard Page Setting the output color space Color matchingPage Setting the monitor ICC profile Scanner color profilesColor matching recommendations Output Color Space Monitor RGBImage processing tools Main window and image-correction tabDimage Scan Dual III Utility Image Processing Guide to image processing tool Tools and functions EffectsImage processing glossary Undoing and redoing image corrections Tracking image corrections Snapshot buttonComparing pre and post correction images Saving image correctionsLoading image-correction Jobs Complementary colorsVariation palette Brightness, contrast, and color balance palette Tone curve and histogram corrections Using tone curves Tone curve and histogram paletteDrawing tone curves by freehand Short guide to tone curve corrections Bringing out detail in the shadowsIncreasing image contrast Correcting colorHistogram corrections Tone curve / histogram auto setting White, gray, and black point corrections Setting the white and black-point values Selective-color paletteUnsharp mask Hue, saturation, and lightness palette 35mm film JOB File ListsAPS film Installed Files and Folders Mac OS 8.6 Mac OSTroubleshooting and Technical Support SolutionChecking Scanner Installation Windows Pixel Polish and Mac OSWarranty and product registration Technical supportTechnical Specifications RAMPrimary RGB and secondary CMY colors Complementary colorsAN Introduction to Color Complementary colors p HSB color model pHue corrections Universal Copyright Convention AV-A209
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