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Spyder Ebook All About Your Color Management

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Spyder Ebook All About Your Color Management 2 3 Spyder eBook All about Your Color Management Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6 Color Management for Photographers | aha Understanding Digital Color | 2 © Copyright 2012 Datacolor. All rights reserved. 4 5 Spyder eBook All About Color Management Datacolor C. David Tobie – Global Product Technology Manager Color Management for Photographers | aha Understanding Digital Color | 4 © Copyright 2012 Datacolor. All rights reserved. 6 7 Chapter 1: aha Understanding Digital Color Preface 4 Color Measurement Hardware 6 What exactly do ICC profiles do? 10 Framework 10 ICC Background 12 ICC in Practice 14 1. Color Models 14 2. Color Spaces 16 3. Color Profiles 16 Photos in RAW Format 18 RAW Data 18 From Image to Workflow 20 Benefits for Photographers 20 Benefits for Digital Artists and Designers 22 Problem Areas 22 DNG (Adobe Digital Negative) 24 Color Management for Photographers | aha Understanding Digital Color | 6 2 3 Color Management for Photographers | aha Understanding Digital Color | 2 4 Preface 5 Preface High quality digital photography with if color accuracy was required it could era chip captures an image using an Anyone who has ever tried using an RAW files is no longer a complex sci- only be achieved using specialty labs RGB color model. “RGB” stands for red, artist’s paint kit to mix an exact color, ence, but can now be quite easy to at premium prices. green, blue, and refers to an additive has a rough idea of how difficult it is to achieve: A photo is reviewed on the Working in the current digital “dark- color space, similar to the red, green, reproduce colors as seen by the eye, camera’s LCD screen and downloaded room” on your desktop has many ad- blue color cone system in the human using dyes or pigments. Many ama- to a computer for editing. There you vantages. But the photographer or eye. teurs can live with the color differences can adjust, retouch, and print. Even for designer is now responsible for the After copying the images to the com- of an uncalibrated system. But serious the non-technical person these pro- technical problems that can occur be- puter, we see the pictures on a moni- photographers and professionals can- cesses work well today, after a short tween capture and print, and the final tor, using the RGB colors the camera not. and painless learning curve. image color. produced. Already we are dealing with The goal of this series is to teach you But the professional photographer Colors do not automatically show on two devices that have different color what you need to know to control your was not always responsible for color the computer monitor exactly as they capabilities, and which define color dif- digital color. management. Previously they shot a are defined in the image file. Techni- ferently. If the image is then sent to a photo, had the film developed, and cally, this is not surprising: working printer, the printer driver converts the received chromes or proof prints from with three different devices that do data again; moving us from the colors the lab. If the colors were not accurate, not share a common denominator is of the light the camera saw, to inks - no one blamed the photographer. But bound to cause problems. The cam- using anywhere from 4 to 12 ink colors. Color Management for Photographers | aha Understanding Digital Color | 4 6 Color Measurement Hardware 7 Color Measurement Hardware Color management without additional Anyone who has shot with digital or color measurement hardware is possi- film cameras has seen that these de- ble – but the results it provides are not vices interpret color differently than all that accurate. To use color manage- the human eye, depending on the na- ment, but then not get well managed ture of the film or digital system, and color seems contradictory. But color the optics used. Compact digital cam- management in everyday practice re- eras often provide strong bluish colors, We can have more control with a comes to the printing of images on pa- quires accurate display of images on poor quality lenses produce color-casts digital image displayed on a monitor. per, we see further device effects from the monitor, and matching images and vignetting, and each film emulsion But here we also see effects of the de- the printer, paper, and inks. One needs from the printer, and the process to responds to light in a different way. vice on color, the brightness of the dis- not to have studied physics in order reach this result requires more than Given these variables, using color crea- play, its color gamut, how it interprets to be able to understand that this all software-only solutions provide. tively, not precisely, is the easiest solution. highlights and shadow detail. When it leads to color and density errors. Color Management for Photographers | aha Understanding Digital Color | 6 8 Color Measurement Hardware 9 The time spent on reading color charts to create printer profiles decreases, reading the entire line in on pass. The issue is precise color definitions The wiser choice is to invest in hard- for special ware to make these measurements and papers. adjustments for you. This brings ac- curacy and objectivity to the process for a few hundred dollars. Basically, you need two different devices: one for emitted colors on the monitor and one for the reflective colors in prints. Measurement capabilities and prices are now quite reasonable, and differ- ent options are available for more ad- vanced users and special needs. There are differences in printer pro- filing processes. Manufacturers target In short: We move beyond the physi- coarse units, and on the other hand photographer – to adjust the screen different groups: Some specialize in cal world of color and rely on multiple must depend on the agility of their successfully to match the densities of the higher priced specialty segment digital devices that interpret colors eyes. Unfortunately the eye quickly ad- prints. serving prepress (CMYK offset printing) differently. If you look at the this color justs to color casts, as can be seen by But even for the black and white and others in more affordable tools clutter armed only with your eye, at- changing display profiles; what looks photographer, the money invested in designed for amateur photographers, tempting to create corrections for wrong at first, soon becomes typical. trial-and-error sample prints would which are today in the language as a each of these devices is beyond hu- Regardless of whether the colors be better invested in a good monitor marketer “Prosumers”. man capabilities. Some people stop be- are right or wrong, our brains adjust calibration tool. This would then assure Datacolor products target the mid- ing aware of these variations, because to color cast within minutes - similar a universal correction, not a device- priced segment that we are addressing their eye adapts to the differences, and to the way we can adapt very quickly specific match to one printer. Such here, focusing primarily on advanced they mentally compensate. Those that to the lightness or darkness of an en- one-on-one matching of a screen to a and professional photographers as are color sensitive despair, because on vironment. It is actually possible for printer fails when a different display well as fine art printmakers. However, the one hand, they are expected to ad- a photo lab professional - especially must be used, or a different printer is Datacolor products also address vid- just color with primitive controls and when working with a black and white required, say for a larger print. eography and other related uses. Color Management for Photographers | aha Understanding Digital Color | 8 10 What exactly do ICC profiles do? 11 What exactly do ICC profiles do? Framework “An ICC profile is used to describe the point, the color management system characteristics of a device recording (CMS) of the computer’s operating sys- Before you deal with color profiles in and display of color, to compensate tem. There, the variations are checked the color channels to remain balanced. detail, you should keep this in mind: for errors in color reproduction.” This and balanced. Ideally, this results a uni- Inkjet printers are relatively constant Working with profiles does not neces- catchy definition by Andreas Kunert formity of color reproduction in all de- over time, but vary depending on the sarily improve the visual elements, but (from: Color Management in Digital vices, providing reliable results. paper and the ink used. Laser printers, does improve the technical elements Photography, Bonn, 2004) illustrates Unfortunately, it is not enough sim- on the other hand, vary with tempera- of an image. A photo may look “pretty” the principle of ICC-based color work- ply to profile each device once to use ture and humidity, requiring seasonal without color management, but it may flows: to assure accurate reproduction it afterwards in any situation. Moni- reprofiling. Digital cameras need to be at the same time be less accurate. Accu- of all devices; camera, scanner, moni- tors change over time. Here repeated corrected for white balance and color racy and consistency first, can allow at- tor, and printer, have a description of calibration is necessary for the color calibration for different lighting situa- tractiveness to be produced later, with- their color at the central collection temperature to remain constant and tions and workflows. out compromising color management. Color Management for Photographers | aha Understanding Digital Color | 10 12 What exactly do ICC profiles do? 13 ers. The starting point of the consor- tium was an invitation to the commu- nity - Forschungsgesellschaft Druck eV (Fogra) in 1992, with the goal of defin- ing the future of color communication in open computer systems.
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